Full Chisel Blog

January 26, 2012

Cutting Wooden Threads

Spiral threads have been cut in wood for centuries.  I discussed making thread by hand earlier.  During the nineteenth century the tools had been perfected but still retained their original design.  There are two components to threading; there is the screw and the nut.  The screw has external threads and is referred to as the male element and the nut has internal threads and is referred to as the female.  While these can be meticulously cut by hand, it is much easier to accomplish this by using some simple tools.   There are two tools used to make the threads by hand and they are the tap and the die or die box or screw box.  Wooden threads can also be cut on specialized lathes from a design first proposed by Leonardo da Vinci.  This discussion will be about using the two hand tools to make the threaded screw and nut.

There is nothing quite like creating wooden threads.  The process is a unique experience and the results can be rewarding.  You are capable of making your own wooden screw clamps, veneer presses, vices and adjustable items such as music stools, embroidery frames and candle stands.  Threading wood is something unique, a wooden nut and bolt is unusual, something that few others have.  The projects, tools, furniture and fun things you can make with a set of these tools are endless.  Wooden threads have always intrigued me; there is just something fascinating about them.

Wooden Thread Cutting Tools

There are two ways to go, the first is to buy a set of wooden thread cutting tools or you can make your own.  The new wood threading tools are of good quality and generally follow traditional designs.  If you choose to make your own you will need to have made a tap of the proper size that you are interested in making.  This should have sharp edges to make clean cuts; a machinist or good blacksmith can fabricate a tap to your particular dimensions.  These taps are similar to modern metal cutting taps except they are larger and have fewer teeth per inch.

Eight teeth per inch is about the minimum for a ½” tap and larger should have 6 teeth per inch and on very large screws for presses 4 TPI to withstand the pressure.  To make a tap the threads can be cut in the metal for the tap and then the four sides flattened to produce 4 cutting edges at each thread.  Regular taps have a tapered end to make it easy to start the tool into the wood.  Bottoming taps are not tapered but will cut to the end or the bottom of a blind hole.  Do not use a bottoming tap for initial threading as it can easily cut off centered internal threads.

There is another old design that has the threads machined on the outside and a hole drilled in the center of the end of the tap.  On the end of the tap, the threads are machined down to form the taper and at the first thread a small hole is drilled at an angle into the large center hole.  This forms a very sharp tooth that cuts and the chips go through the small hole and out the larger hole in the end of the tap.  This type of tap does produce a very smooth cut, but the traditional 4-sided tap, if it is sharp and used properly will also produce clean cuts.  The wooden handle should be strong and long enough to give leverage for the sometimes difficult process of cutting internal threads.  The handle should be rounded and shaped to fit the hand as the hand is touching the handle a lot during tapping.

Once the tap is made it is possible to make the die box and all that is required is a V-shaped cutter that is secured in the box and cuts the external threads.  Unlike the tap, which will cut with four cutters on each thread, the die has only one cutter that cuts all of the threads.  A proper sized hole is drilled for the tap into a piece of hardwood such as beech or maple, see list below.  This hole must be square to the body of the die box.  The holes are then chamfered or countersunk to prevent the tap from splitting out the wood as it enters and exits the hole.

The tap should be lubricated with linseed oil to make the threading easier.  The tap is then inserted carefully into the hole and started squarely to insure a straight threaded hole.  It is very important that the tap is started perpendicular to the surface and square to the hole.  If the tap binds up gently back a ½ turn then start again, if it becomes too difficult, remove the tap, lubricate and try again.  Make sure the exit hole is countersunk to insure that the tap doesn’t break out any wood when it exits.

Now that you have the die box drilled and threaded, the next step is to cut a mortise for the V-shaped cutter that is on the front leading edge of the die box.  The cutter is positioned right over the first complete thread peak at an angle of 30ºand the leading edge of the cutter should engage the wood at the widest part of the cutter first to score the wood being removed.  The end of the cutter is ground at an angle of 15º with the top of the V leaning forward, with the bottom of the V trailing.

The cutter needs to be sharp and set to cut just slightly deeper than the threads that were cut by the tap.  This insures that the newly cut external threads will not bind up in internal threads of the die box.  The die box can also be equipped with a removable plate that will center round pieces as they are fed into the screw box.  The plate needs to be thick enough to line up the piece to be threaded and removable so the external threads can be cut all the way up to the shoulder of a turned piece if necessary.  The internal threads of the screw box should be well lubricated to make the cutting of the screw shaft easier.

Nut – The Nut is the part with the internal threads that are cut with the Tap.  The nut is prepared by drilling the hole using the following starting holes sizes.

Starting holes:

½” threads use a 3/8” drill

¾” threads us a 5/8” drill

1” threads use a 7/8” drill

1 ¼” threads use a 1 1/8” drill

1 ½” threads use a 1 3/8” drill

1 ¾” threads use a 1 5/8” drill

2” threads use a 1 7/8” drill

2 ¼” threads use a 2 1/8” drill

2 ½” threads use a 2 3/8” drill

 

It is important that the hole is drilled square and perpendicular the flat surface of the nut.  The wood for the nut should be a wood that is capable of taking the threads.  While most hardwoods will hold the threads some are better than others.  Beech, maple, hickory and oak can be used for nuts and will take threads, as can alder, elm and poplar.  Some brittle woods such as cherry are difficult to thread, but it can be done.  The thicker the piece of wood that is threaded, the stronger the threads will be.

On thin pieces for the nut, the threads can easily be cut at an angle, so make sure the hole is straight and the threading is done properly.  When threading in an angled hole, the grain orientation is important as is beginning the cutting with the tap.  The tap needs to go straight down the hole; if you get off at an improper angle the threads will be too deep on one side and too shallow on the other.  While the internal threads on the nut are not as critical in terms of strength, the screw needs to be constructed of specific woods.

After the proper sized hole is drilled, the edges need to be chamfered or countersunk to prevent split out during the entry and exit of the tap.  This must be done on both sides, as the tap will chip out the wood.  The tap is lubricated with linseed oil or beeswax and it is inserted in the starting hole.

It is very important to make sure that the tap is perfectly square and lined up with the hole.  The tap is twisted and forced into the wood, taking care to make sure that it is perpendicular to the surface of the nut. Enough downward pressure is exerted to engage the tap into the hole, after the cutting begins, the tap is self-feeding.  If the tap binds in the hole, gently and carefully back it off a half a turn and start again.  If it still binds, back the tap out of the hole, lubricate it again and carefully start the tap back into the cut threads.

Be careful when doing this so you don’t cross thread the screw and ruin your work.  Every once in a while, back the tap out a half a turn and continue until cutting becomes more difficult, then repeat and go at it again.  It is better to take your time and make sure that the work is done properly.  Continue until the tap comes out the exit hole, clean out the shavings and back the tap out of the hole.

If you are threading a blind hole, your starting tap will hit bottom, then back out the tap, remove the dross and carefully place the bottoming tap into the threads and run it down until it cuts the internal threads on a blind hole.  If the wood is fuzzy on the inside of the threads, I wet the piece with water and raise the grain.  I allow it to dry completely and run the tap down the hole again to remove the raised grain and fuzz.  Sometimes running the tap in from the opposite direction will remove the fuzz and clean up the internal threads.

Screw – The Screw is the part with external threads and is cut by the Screw Box or Die.  The selection of the material for the screw is important as certain woods make excellent threads while others are more difficult.  Softwoods are difficult without an extremely sharp cutter in the screw box.  Hardwoods are preferable and woods such as beech, maple and hickory are the best for wooden bolts or screws, those with external threads.  Strong, tough woods such as elm are better than brittle woods like cherry.  Walnut also accepts threads as well.  With care any wood can be threaded.

It is also important that the grain be as straight as possible.  This is for strength and for a more uniform cut.  The piece to be threaded should be turned to the size of the thread box.  Therefore if the threads are for a 1 ½” screw then the dowel or piece should be turned to just under 1 ½”.  All it takes is just a 32nd under to make the piece just the right size.  It may take a slightly smaller say 16th under to get a proper fit, it may take some experimenting.  But I guarantee if it is too large the threads will crumble as it is forced through the screw box.  If it is too large it will not fit into the screw box and if it is too small it will not properly thread through the screw box.  A slightly smaller screw works much better than one that is too tight.  I like nice crisp threads, so I always turn the pieces just under the required size.

For some applications where you don’t necessarily need sharp peaks, such as heavy duty tools, the screw blank or dowel can be slightly undersized producing flat topped threads instead of sharp peaks.  Small fine threads such as 8 threads per inch can be difficult and these fine external threads can easily break off.  Denser woods work better for these fine threads.  If the dowel is undersized, it is important to make sure that the screw box travels over the dowel in a uniform manner to insure proper threading.  If flat-topped threads are required, I usually turn the dowel to the proper size, thread the piece, then re-chuck it in the lathe and turn off the peaks.

When you turn the screw or dowel on the lathe, just use your gouges and chisels, do not use sandpaper.  The sandpaper can leave residue in the wood fibers that can dull the cutter in the screw box.  Also you will want to chamfer the edge of the dowel or screw blank to make it easier to start the screw box.

I always dip the end of the screw blank or dowel in linseed oil to provide lubrication for the cutting process.  I usually clamp the screw blank in a vice to hold it during the threading process.  It is important to make sure that the screw box engages the screw blank or dowel perfectly square to insure accurate threading.  I always look down the waste hole in the screw box where the chips come out to see how the cutter engages the threads.  I try and exert enough pressure to engage the wood on flat grain first rather than the side grain.  It just seems to start better if the cutter enters the wood on the flat grain.

Once the cutter has began to make threads they engage and pull the screw blank into the screw box, so the pressure can be reduced.  After cutting begins, simply turning the screw box is sufficient.   When the cutter has made the first part of the threads, they will engage the internal threads of the screw box and advance the screw into the tool creating a perfectly cut spiral thread.  The first ½” or so is usually not perfect and I always allow for an extra half inch or so to cut off after the threads have been cut.

Once the cutting has started, the tool should ‘sing’ through the work.  If the stuff is tight in the tool, the cutter may be set too shallow or the dowel is too large.  Most screw boxes have a removable plate that guides the screw blank into the screw box.  This is removed if the threads are to be cut up to a shoulder.  The plate should be used to cut well into the screw blank and can be removed to thread just the last inch or so.  A properly positioned and very sharp cutter will make the cutting much easier.

It is important that you keep your tools sharp and well maintained.  The teeth on the tap need to be clean and sharp at their cutting edges.  The new made tap and die sets require sharpening.  The screw box has a V cutter that needs to be honed mirror shiny on the outside and perfectly flat on the inside. The V-shaped cutter in the screw box should be ground at the proper angle of 15º and should be very sharp and properly positioned.  The bevel is ground on the outside of the cutter.  Both edges must be honed for a good clean cut.

New set of ¾” taps and V-cutter, factory ground, NOT sharp.  Note improper ground V-cutter, burr protruding from the bottom of the V.

New set Sharpened.  Threads and slots have been dressed and V-cutter sharpened and honed.

The tap needs attention as well.  The V-teeth need to be dressed to remove the grinding burr left during manufacture.  Make sure to get both sides of the slot and both places where the slot and the V groove meet, especially on the leading (cutting) edge.  Use a triangular file to dress the teeth.  Use a thin flat mill file to dress the gullets so the cutting edge is sharp.  Then go back and re-dress the V-grooves with the triangular file to remove the last of the burrs.

The sharper your tools the easier the work.  I use a bit of sandpaper over the files to hone the edges to a mirror gloss.  Your holes need to be clean, straight and countersunk and your turnings need to be of the proper size and chamfered to produce the desired results.  Use linseed oil or beeswax to lubricate the parts being cut, it just makes the job easier.  Make sure the tool engages the work squarely to produce quality work.

Clean out any shavings that can interfere with the cutting operation.  Work slowly and carefully.  This is not like cutting metal threads; it is a continuous operation, only backing out when the cutters jams or the cutting is complete.  After you are finished using the tool make sure to clean off all excess linseed oil before it dries!

There is no end to the possibilities for using wooden threaded devices and the results are delightful.  Wooden screws are capable of exerting incredible pressure when used for clamping applications and can provide for ease of assembly and disassembly for transportable furniture.  There are endless applications and uses of wooden threads and they are fun to make.

Stephen

January 24, 2012

International Shipping of Books

Filed under: For Sale or Trade,Publications,Uncategorized — Stephen Shepherd @ 9:59 am

I had to add an additional $10.00 to cover the cost of international shipping.  I have received several orders and the rate I have posted is for domestic shipping.  Instead of adding an additional button to each order, I have just added this new button.

So if you are placing an order and you live outside of the United States please add the additional international shipping charge.  Full Chisel Store.

Thank You

Stephen

January 19, 2012

Back in Business

Filed under: Of Interest,Uncategorized — Stephen Shepherd @ 3:17 pm

My blog and website have been off line for a couple of days due to changing host server.  I can now get back to work.

Stephen

January 12, 2012

Preparing for the 18th Century

Filed under: Finishing,Furniture,Historical Material,Of Interest,Publications,Uncategorized — Stephen Shepherd @ 11:35 am

One hundred years before my general interest in woodworking technology [being the 19th century see Shepherds' Compleat Early Nineteenth Century Woodworker], I do have some understanding of the earlier tools, materials, and techniques of the 1700′s.

I have a couple of projects ahead that requires 18th century material.  So in order to prepare for this I thought I would start at the ground floor and work up.

I traded for these ‘straights’ [the common name for shoes that are neither left nor right footed] from Sir George and they came with some awful* reproduction buckles.  I traded a pair of Fry lanchet shoes for these Fugawee shoes, but kept my buckles I got from the Sutler at Mount Misery back in 1976, those on the left.

*The forks on the large military shoe buckles are too long, as you can see in the before picture.  I nipped them off and filed them to a point, trimmed the lanchets and made new holes.  The buckles work just fine now.

I will break the shoes in by wearing them for a day then switching shoes the next day, I am however open to hiring someone to break them in for me.

Now, I guess I need a pair of knee breeches and maybe a Moxon wig.

Stephen

January 1, 2012

Carving Chisels and Gouges

 

Carving chisels and gouges differ from cabinet chisels and other gouges in that they are usually somewhat thinner and are sharpened with a finer angle on the cutting edge.  Some are intended for handwork only while others can be struck with a mallet and of course are never struck a metal hammer.  They have thinner blades and handles that are easy to control, are comfortable and don’t tend to roll on the bench.  I have replaced every round handle on my carving tools with a tapered octagon handle.  This eliminates any rolling of the tool, when I place it down on the bench it stays there.  If I am using a series of chisels and gouges for a particular job I have a mat, a piece of carpet that I use to lay the tools down on to protect their cutting edges.  I also point the sharp ends away from me on the mat to protect me from the very sharp cutting edges.  Most carving jobs are done with two or three tools; sometimes a couple of more but each carving job can require different tools to accomplish the task at hand.  Therefore if you intend to do a lot of carving you will want to equip yourself with the necessary tools.  While both chisels and gouges come in different sizes and with gouges different sweeps you can invest a substantial amount of money to have all of the various sizes of chisels and different sizes and sweeps of gouges.  There also Palm Chisels and Gouges that are smaller versions usually with mushroom or knob type handles for ‘better’ control of these tools.  I have several of these small ‘palm’ tools but like my other chisels I have replaced all of their handles with long tapered octagon wooden handles, I just find them easier to use and they all match.   Large heavy duty carving tools can have socket handles but the most common have tangs to secure them to the handles.

Back Bent Chisel is a regular flat chisel with the blade bent backwards to a curved chisel.  The advantage of this tool is that it brings the cutting angle down very low to produce a finer cut.  The bevel is ground just the opposite a regular chisel with the bevel on top.  Useful for rounding over and shaping convex and protruding detail work.

Curved Chisel is a flat chisel with a blade curved opposite the bevel and is used to get down into areas that need to be flattened.  The curve of the blade will allow for the cutting angle to engage the wood fibers at a low angle.

Double Bevel Chisel is a special carving tool that has a bevel ground on both sides of the blade.  This tool, usually with a straight blade is used for cleanup work; the double bevel is not good for layout work as the blade pushes in both directions when it is plunged into the cut.  Single bevel tools are used for striking the work into the groundwork.  This tool is also available is a skew, which is handy because you can easily reverse it to get into tight areas.

Fishtail Chisel is like a regular chisel but of lighter weight and the blade tapers from wide at the cutting edge to narrower at the tang.  One great advantage to this tool is that it can get into tighter areas; the angle of the taper allows the cutting edge to work up against a shoulder or other interior detail.  These chisels are usually more flexible than regular chisels.

Flat Chisel is very similar to a bench chisel in that it has a flat blade and the cutting edge is at 90º to the blade.  The blades are usually manufactured with a tang and are thinner than a cabinet chisel and may or may not have bevels up the sides of the blade.  Because of the thin nature they are more commonly like a firmer with no side bevels.  One of the more useful carving tools a surprising amount of work can be done with a flat carving chisel.  Most are ground at a fine 15º angle on one side of the chisel.  Some are ground with a double bevel. The single bevel is used to layout and strike work into the groundwork.  Also called a firmer or carving chisel.

Skew Chisel is like the flat chisel but the cutting edge is ground at an angle to the blade.  The skew angle can be either left or right and ground on one or both sides.  When ground on both sides the skew is reversible, if it is ground on one side then a pair may be required.  These chisels cut smooth because of the skew angle and can get into tight corners for easy clean up.

V-Chisel is also called a veiner and is used to add V-shaped details in wood.  This tool and the U-Chisel are used only for shallow work; if deeper V-cuts are needed straight chisels are used to cut down both sides of the v-groove.  Like the U-chisel curved cuts can present grain direction problems.  I make my first v-cut shallow on the side of the curve that is with the direction of the grain.  I then reverse and make my second v-cut to final depth with the grain of the wood.  Tipping the tool up when engaging the wood will start the cut on the top edge of the wood first preventing chipping out.  Some of these chisels are sharpened with the outside edges projecting further than the center part of the V.  This allows the tool to score or cut the wood ahead of the V to prevent tear out.  This tool can also have a bent blade such as a long bend or short or spoon bend to just the end, allowing v-cut detail work in deep excavations.

Dog Leg Chisels are also used for carving work and are referred to as entering or cornering chisels.  These tools are particularly handy, the offset or dogleg is usually in the shank just at where the blade starts to widen out.  This offset allows the back of the blade to be flat keeping the cutting angle low for a smoother and easier cut.  In a set of three there is a straight blade, left skew and right skew to handle any application.

A gouge is any chisel with a curved cutting edge; this includes even very low sweeps or curves.  If it is curved it is a gouge.  Some heavy-duty carving gouges are quite similar to a bench gouge, but most are smaller, thinner walls and lighter duty and they are sharpened to a finer edge.

Back Bent Gouge is a handy tool for finishing off curved convex surfaces.  The bevel is on the top and this tool can perform functions that no other single tool can accomplish.  While you can do the same with a flat chisel, the back bent gouge can do the same job in one or two strokes.  The back bend can be on full-length gouges as well as the spoon gouge shape.

Curved Gouge is a gouge with a curve to the shaft allowing the tool to work on deep inside curves.  The curve along the length of the shaft gives a lower angle of attack to the cutting edge.

Fishtail Gouge is a lightweight gouge that has a wider cutting edge and the shaft tapers back to the tang.  The fishtail gouge like the fishtail chisel in that it is flexible and the taper allows the sides to be moved up next to a corner or edge without the shaft interfering with the cutting action.  The fishtail also makes the gouge lighter weight, as there is less metal in the blade.

Flat Gouge is the standard classic carving gouge.  With thinner walls and lighter construction than a Cabinet gouge, this tool comes in many sizes and sweeps to the curve.  The shaft is straight and attaches to the handle usually with a tang in some rare instances a socket.  The bevel is ground on the outside or convex side of the gouge.  When used for laying out and working the background this chisel is used to follow the sweeps of the curves in the carvings.  The appropriate sweep is chosen to match the pattern for the carving.  You can see why you might need several sizes and sweeps of this tool to match all curves that might be encountered.  A special grinding (on the inside) to this tool produces an ‘in cannel’ gouge and the outside of the tool can be used to do the lay out and initial chopping.

Fluting Gouge is similar to the flat gouge but usually have a greater sweep with high thin walls.  More of a U-shape these tools are great for deep flutes and other deep detail.  When using a gouge it is important that sometimes when you are cutting you are cutting with the direction of the grain on one side and against the grain on the other side.  Always be aware of the direction of the grain and cut first on one side and finish up the other direction on the other side of the flute.

Spoon Gouge has a shaft that becomes a spoon shape near the cutting edge.  With more curve along the length of the shaft than a curved gouge these tools are ideal to get down in the bottom of bowls, spoons and other steeply sided excavations in the wood.  The curved shape to the spoon also gives added leverage to the cutting process.

U-Chisel should actually be classified as a gouge as it has a curved cutting edge.  This very fine U-shaped edge is used for adding details and fine u-shaped cuts into the wood.  When using this tool always keep in mind that on curves one side is with the grain and the other side is against the grain.  I do the initial cut a little shallower in the correct direction for that cut.  I then I do the second cut in the other direction to keep me working with the grain of the wood.  This tool can also have a bent blade such as a long bend or short or spoon bend to just the end, allowing detail work in deep excavations.

Individual wood carvers have their own preferences for how the tools are sharpened.  Most agree on a fine angle of 15º for the bevel on the cutting edge.  Many sharpen a secondary bevel on the cutting edge, but I prefer a single 15º bevel that is flat and not hollow ground.  The problem with hollow grinding is that it is impossible to polish the entire bevel, which I believe makes for a smoother and easier cut.

As for storage of carving tools, the tool roll of canvas or leather is popular as is hanging the tools up on the wall to both display and keep the cutting edges from getting dull by banging into each other.  This can happen if they are kept in a drawer.  A drawer will work if it has dividers that separate each tool.  I have used tool rolls and they are handy if you have to take them out of the shop but for storage and accessibility I prefer to hang them up and show them off.  After I use my carving tools, I always wipe the blade down with turpentine to remove any pitch or sap that might be on the blade.  I also keep my entire tool bright and free from rust.  A tool that has a bright finish will not tend to rust as one with just a ground surface.  I also check the sharpness and touch up the blades if necessary so they are always sharp and ready to go.

Stephen

 

December 28, 2011

‘Little Shaver’ – product review

Filed under: Historical Material,Of Interest,Proper Tools,Reviews,Sharpening,Uncategorized — Stephen Shepherd @ 10:26 am

Annually, my family selects names for gift exchange as well as a list of items as suggestion for gift ideas.  And this year this tool was on the top of my list.  Originally produced in the early 1900′s, it looked like a cool tool and is available from Lee Valley.

I don’t use any of my chisels or sharp knives to sharpen graphite pencils as they leave residue on the blades and is tough on a fine edge.  I have a designated small clip point knife that I use for pencil sharpening, now I can clean it up, sharpen it and keep it for other purposes.

As luck would have it I got the sharpener, thanks Travis [great nephew].  It worked right out of the box, although when I get back home to my shop I will hone the blade just a bit.  I also noticed a small casting defect [to the right of the cone], but it doesn’t effect the operation.

I first tried #2 pencils which were made to a surgical fine point and later on a 3H pencil.  To my surprise it got that very hard graphite to the same degree of sharpness.  I then tried to sharpen a tiny pencil I keep with my pocket ivory notepad and it worked.  I am impressed.

Stephen

December 22, 2011

Chisels and Gouges

Filed under: Historical Material,Of Interest,Proper Tools,Uncategorized — Stephen Shepherd @ 10:41 am

 ‘Some folks carve their reputations, others just chisel and gouge.’

 

Chisels and gouges are two very important tools groups the first of which is a very common woodworking tool. A chisel as a flat blade to cut flat straight work and a gouge has a curved blade to cut curved and other shapes. Chisels are usually sharpened with a bevel on one side with the back of the chisel being perfectly flat. Some carving and turning chisels are double beveled for their particular application. Both chisels and gouges cut with the cutting edge perpendicular to the grain of the wood but the cut is much smoother if the cutting edge is held at an angle or skew to the wood grain. The direction and amount of the angle depends upon the type of wood and the grain. Cutting can also be easily accomplished on certain occasions and applications by cutting across the grain of the wood; this is especially true with gouge work. I will mention this at the beginning and will not talk about it again but never, ever strike a chisel with a metal hammer of any kind. Always use a wooden mallet to strike a wooden chisel or gouge handle.

Back Bent Chisel is a specialty chisel used mainly in woodcarving. The advantage of a bent chisel is that the bend in the blade changes the angle of attack of the cutting edge. You can get into difficult areas to deal with difficult grain and this tool can do that where other chisels cannot.

Bench Chisel is a term to describe a typical woodworking chisel used by cabinetmakers, furniture makers and others. It is of full size with a 5” blade and 5” handle and is usually a tang type but older ones do come with sockets. The blades are not too thick and the tops are beveled along the sides. The reason for the bevel is to allow the chisel to work on dovetails, with beveled sides, that is possible, if the sides are square like on mortise chisel or firmer chisels they will damage the sides of the dovetails. The bevels also lighten the chisels weight.

Butt Chisel is a smaller version of the bench chisel with a short blade and short handle. These are used for installing hardware such as butt hinges and are small enough to carry in the toolbox for work out of the shop. Some bench chisels become butt chisels after repeated sharpening.

Cabinet Chisel is another term for Bench Chisel and denotes the bevel edge wooden handled chisels in sizes: 1/8”, ¼”, 3/8”, ½”, 5/8”, ¾”, 7/8” and 1” are common and in increments up to 2”, after that they are usually considered a Slick. These are the common everyday chisel used by the cabinetmaker, carpenter, furniture maker and other woodworkers doing normal woodworking tasks.

Carving Chisel generally has a thinner blade and is sharpened to about 15º angle which is easier to use when hand carving as opposed to mallet carving.

Corner Chisel is another specialty tool that comes in small ¼” size for cabinet work to 1 ½” and larger size for building and boat construction. This tool has a blade that is formed into a right angle along its length with sockets on the large versions and tangs on the smaller ones. The tool is ground flat on the outside and the bevels are cut on the inside leading edges. The sharpening is a thicker angle for heavy construction work at about a 25º angle to prevent chipping of the blade. Small cabinet corner chisels have a finer 20º angle to square up mortises and other right angle joints. Also called a bruz.

Dogleg Chisel is a handy tool to have for working the bottom of shallow mortises and for truing up groundwork during the inlaying process. The offset or dogleg is usually in the shank just at where the blade starts to widen out. This offset allows the back of the blade to be flat keeping the cutting angle low for a smoother and easier cut.

Firmer Chisel is similar to a bench or cabinet chisel but without the bevels up each side. The blades are usually thicker and some old ones have a curved top to make the blade even stouter for heavy-duty work. Most handles are joined to the firmer with a socket to withstand the heavy mallet work associated with this robust tool. Some of the handles have a hoop around the top to prevent the head of the handle from splitting and mushrooming. The cutting edge bevel is ground to a 20º angle to withstand the heavy work, prevent the blade from chipping yet cut easily. The mass and strength of these tools withstand the heavy use to which these tools can be subject. Larger versions are also called framing chisels.

Fishtail Chisel is a lightweight chisel that should probably included in Carving Chisels but I use mine all of the time where access is limited. The chisel, a tang type has a thin shank that flairs out to the finished width at the cutting edge of the blade. The shape forms a fishtail and while it works for some applications, the shank is too flexible for some purposes. The blade is sharpened on a low 15º angle like a paring chisel, is extremely sharp and makes light cuts easily. Also called a fantail chisel.

Mortise Chisel is a stout square or rectangular blade with a thick shank and joined to the handle with a socket or tang and ferrule. The squareness of these blades produces square mortises. The stoutness of the large thick blades withstands pounding with a mallet and levering against the walls of the mortise to clean up the bottoms. Smaller mortise chisels are ground at 20º while large construction mortise chisels are ground to 25º.

Paring Chisel is a long thin usually side beveled chisel used for fine smoothing and finish work. The long thin blades are flexible and the cutting edge is sharpened to the low 15º angle to provide the smoothest of cuts. These tools are almost always with tang handles and are never struck with a mallet. The length and suppleness of these chisels are favored by patternmakers and are delightful to use.

Slick is a large chisel 2” wide and wider with a long blade and invariably has a socket with a very long handle sometimes with a pad turned onto the end. These are used to shape large construction members in building and boat construction. The pad on the handle is placed against the shoulder, which is used to force the slick through the work. The length and mass of this tool make it a tool that is relatively easy to use. Slick is also a term to describe any chisel over 2” wide.

Socket Chisel is a type of chisel that holds its handle within a socket formed on the shank of the chisel. Socket is a method of attaching the handle to the blade. A socket can be used on any type chisels and most types in one form or another are to be found with a socket. This type of chisel is usually of the heavier types capable of taking pounding on the handle. One problem with socket chisels is that when the handle breaks, most people apparently just kept hitting the socket itself mushrooming it over.

Swans neck Chisel is a special type of chisel used to smooth the bottoms of mortises or other deep holes in wood. With the curve on the end of the chisel, the blade is at the correct angle to properly smooth the bottoms of mortises. Also called a Bottoming Chisel.

Tang Chisel is another type of chisel construction in which a thin tapered part of the shank (the tang) is inserted into a handle. Tang is a method of attaching the handle to the blade. There is usually a bolster or shoulder between the tang and the blade that rest against the handle. This type of construction is usually for lighter duty chisels. The tang should be properly fit to prevent the handle from splitting. Many of these types of chisels also have metal ferrules to prevent splitting.

Turning Chisel is a flat chisel that is used specifically for turning on the lathe. I have used cabinet chisels and skew carving chisels on the lathe in a pinch but most often the tools are sharpened differently to be interchangeable and I have never used a turning tool as a bench tool.

And now for a discussion about bent chisels, commonly referred to as the Gouge. Gouges are chisels with a curved or bent cutting edge that makes curved or bent cuts or gouges in the wood. Even the slightest amount of bend qualifies as a gouge. The bevel of the gouge is usually ground on the inside or concave side of the gouge and the back is flat. An in cannel gouge has its bevel cut on the outside or convex side of the gouge and the inside is flat.

Back Bent Gouge is a gouge with a shank and a short blade that has a reverse bend in the blade and is useful for low angle work during modeling and shaping. These are usually fitted with a tang handle arrangement and are seldom struck with a mallet. An unusual tool that is handy on those occasions when this tool is the only solution for tricky grain and rounded undercuts.

Bench Gouge is a gouge to do simple hollowing work such as moldings and coves. These are light duty gouges with a tang handle. Also called cabinet gouges these may be the only gouges that many woodworkers need for simple hollowing operations.

Bowl Gouge is a short stout wide bladed gouge used for making the hollow inside of a bowl as the name implies. The blade can be straight but are usually curved along its length to fit down into the bowl. The handle is also short to accommodate working inside of bowls and trenchers. Most are socketed to withstand mallet use and the end of the handle is hooped to prevent splitting.

Cabinet Gouge is another name for the group of lighter duty Bench Gouges.

Carving Gouge is much thinner and lightweight, than other gouges and usually not as long and invariably fitted with a tang handle and sharpened to 15º angle.

Fishtail Gouge similar to the fishtail chisel this gouge is usually small and light duty. The nature of the fishtail limits the useful life of this tool. The blade keeps getting narrower as the tool is repeatedly sharpened. An advantage is that the tool can get into places its wider counterpart cannot. Also called a fantail gouge.

Firmer Gouge is a heavy-duty thick bladed tool fitted up with a socket and hoop handle to handle the repeated blows from the wooden mallet. These tools can take a lot of abuse and have application in large ship and building construction as well as tool making and mill work. The cutting edge is sharpened 20º for finer work to 25º angle for heavy-duty gouge work.

Paring Gouge is a long thin bladed gouge used for pattern making and fine carving work. Fit up with a tang handle these tools are used with hand power and are not struck with a mallet. The angle of the cutting bevel is a low 15º angle for smooth effortless cutting. Some of these tools were sharpened with the bevel on the inside, called in cannel sharpening.

Socket Gouge can be any gouge that has an iron socket formed on the shank of the blade into which a turned wooden handle is inserted. The handle has a taper on the end to precisely fit in the metal socket. This type of handle/tool connection takes the most abuse when pounding with a mallet. Unfortunately many were used without handles and struck with iron hammers and have mushroomed over. These can be restored if you have access to a forge.

Spoon Gouge is another handy tool for working inside of concave surfaces such as bowls and deep carvings. The spoon is bent along the blade in the same direction as the sweep of the curve of the gouge. This enables the tool and handle to be at the lowest angle possible. Some are light duty and have just a small spoon at the end of the shaft; others are large and have the hollow spoon shape along the entire blade. The cutting edge bevel is usually sharpened on the inside or concave side of the gouge to a suitable angle for the type of work that it is being used for. Rough out work will have a greater angle than will fine inside smoothing which needs a shallower angle to work properly.

Tang Gouge is any gouge that is attached to the handle by a sharp tapered end on the shank of the blade. Some have bolsters or shoulders, swaged on the shank to prevent the tang from working deeper into the handle splitting the wood. Many gouges with tangs also have iron or brass ferrules around the handle where the tang goes in.

Turning Gouge is almost always a long blade tang fit into a long handle. The longer the blade and handle the easier a turning gouge is to control. Like long half cylinders the turning gouge is used to rough out work on a lathe as well as doing the intricate hollows and coves of turning spindles and for roughing out faceplate work. The end is sharpened different from cabinet gouges in that the angle is much steeper angle of 30º. The tool is not usually honed, as some prefer a burr on the cutting edge of the turning gouge. The end can be ground straight across for roughing work or the cutting end can be rounded like a thumbnail for more delicate turning on an inside radius.

 

Chisel and gouge handles fall into two basic types, those for tang tools and those for socket style tools. The wood for tool handles should be of a hard, strong and stout wood that will resist splitting and breakage. Boxwood, apple wood, beech, hornbeam and maple make excellent tool handles that resist shock and splitting. Hickory, white oak, ash and elm work well especially for socket handles with ferrules and hoops. Dogwood, ebony, rosewood and other dense and strong woods can make good handles. Ferrules are cylinders of metal; iron or brass that reinforces the end of the handle where the chisel or gouge shank and tang enters the wooden handle. A hoop is an iron or brass, reinforcing ring that is placed in a rabbit turned or formed around the top of the handle where the mallet strikes the tool. As the wood is struck with the mallet it spreads out and the hoop prevents the tool handle from splitting. The shape of the handles varies but some standards have come about. Having different types of handles for different types of tools gives you a visual clue to the tool by the shape of the handle, which can facilitate picking the tool from all of those cluttering up the work bench.

 

Cabinet Handle has octagonal handles in cross section with turned rabbit for a hoop and a turned bulbous knob just before the rabbit for the ferrule of this tang mounted chisel or gouge. The cove before the bulb knob gives a place for the fingers and thumb to grip the tool and the octagonal handles give control when using a mallet.

Palm Handle is a short stubby type of handle that is a rounded mushroom shape knob into which is inserted small tang chisels or gouges. The wide topped knob spreads out the pressure of the tool to the hand and gives good lateral control because of the surface of exposure to the grip. Does not have the leverage advantage of a longer handle.

Pattern Maker Handle is similar to the Round Handle but has turned round cylinder handles but with the same bulbous knob on the end and is slightly longer. The long flat nature of the tool does not tend to roll like other chisels and gouges.

Round Handle in both single taper and double taper is a common chisel and gouge handle. While turned the style is very simple and can be for both tang or socket applications. One problem with round handles is that they tend to roll and there is nothing worse than a sharp chisel or gouge falling on the floor after rolling off the bench. A good overall handle on a tool that will be used for handwork and with a mallet.

Socket Handle is any style handle that has a turned cone, which fits, into the metal tapered socket on a tool with a socket for the handle. The fit should be tight to insure that the stresses are spread out evenly along all surfaces of the end grain of the wooden handles. Some are turned with shoulders that engage the top edge of the socket and are flush on the outside surfaces.

Tapered Handle in an octagonal cross section is my favorite tool handle. It does not roll of the bench, it is easy to control and can be used for handwork as well as light mallet work. I start with square stock and taper off the corners. I then taper off the flats toward where the tang enters the tool. It is wider at the back to disperse the force of the palm of the hand against the tool as well as provide a wide area of surface to strike with a mallet. The octagonal shape is easy to grip and provides excellent control of the tool.

Turned Handle for both socket and tang applications can have some nice curves. Turned on a lathe these handles will have swellings on the back end to provide a good hand surface as well as one that can be struck with a mallet and can have a slight swelling near the ferrule or socket for a thumb and finger rest. Decorative beads, lines, moldings and details can also be turned into the surfaces of the tool handle. Some of the older designs have quite pleasing designs, details and decorations to make them beautiful as well as functional. Turning Tool Handle is much longer than the regular chisel or gouge handle. Usually with a large ferrule to reinforce the end of the handle to the force to which it is exposed during turning the length gives a necessary leverage advantage necessary. Both longer and larger in diameter, it is shaped to fit comfortably in both hands and smooth enough to provide a good grip for control of the turning tool. The size is necessary for strength required for the constant forces of turning. A traditional flaring at the end or a knob turned on the end gives a tactile reference when picking up the tool.

Taking care of chisels and gouges should be a matter of course, always protecting the cutting edge, using only wooden or rawhide mallets, never metal hammers and keeping the blades clean, the handles in good repair and the edges very sharp. You can use a chisel roll made of leather or canvas to store your tools or you can make a drawer that keeps the tools separate. You can also make a rack on the wall of the shop or in a toolbox to hold the tools in position. If the ends of the handles become frayed with repeated mallet work, it is a good idea to file off any mushrooming of the wooden handle. Smooth over the top of the handle to insure that the mallet strikes it squarely. I prefer a round carver’s type mallet as they strike the same with every blow and do not have sharp edges that can split tool handles. Treating the handles with periodic applications of linseed oil will consolidate any frayed and dried out wood and make the tools look good. A very light coat of linseed oil on the blades will prevent rust from forming, also keeping the tool sharp and bright retards rust. When fitting up new socket handles make sure that the outside taper of the handle matches the inside taper of the socket exactly. When fitting up tang tools into handles, make sure that the square tapered mortises are exact to fit the metal tang. If the mortise is too small, the tang will split the handle when it is driven in place. I apply rosin to the tang of the chisel as well as the socket to help secure the handle in place. Keep these tools sharp and prevent the cutting edges from knocking into each other and other metal objects. Always be aware of the cutting edge of the tool and its relationship to you and you will never be accidentally cut by your sharp tools.

 

December 14, 2011

Progress of Sun-thickened Raw Linseed Oil

I started this small batch of raw linseed oil in April and it has been exposed to sunlight every day since then.  I have done several experiments with raw linseed oil all of which are covered in Shellac, Linseed Oil, & Paint – Traditional 19th Century Woodwork Finishes.

The oil started out much darker and less viscous and with the action of the sun it has lightened in color [with the chlorophyll being bleached out] and it has thickened up.  Because it is oil I let it stay outside even in the freezing weather.

The other morning [it was 17 degrees F] I noticed that the oil had clouded up, so I took a photograph of the cloudy oil.

I took the oil inside and allowed it to warm up overnight and it clarified.  Could be residual moisture in the oil that cause the turbid appearance.

I will keep it in the house in a sunny window and let it continue to thicken up.  I do open the bottle occasionally and have noticed that the odor is much milder than fresh raw linseed oil.

Stephen

 

 

 

December 12, 2011

Furnishing Louisiana, Creole and Acadian Furniture, 1735-1835

Filed under: Finishing,Furniture,Historical Material,Of Interest,Publications,Uncategorized — Stephen Shepherd @ 1:08 pm

I just received this rather large publication by the Historic New Orleans Collection from John H. Lawrence, Director of Museum Programs.  The book is 9 3/8″ wide, 12 3/8″ long and 2″ thick while weighing in at 9 pounds, 538 pages and 1500 illustrations most in color.

As it will take some time to get through the written material, the color photographs of the furniture together with historical documents makes for a rather in depth look at early furniture from the Mississippi River Valley.

There were even illustrations of a few painted and grained examples with many having been stripped of their original painted finishes.  I am surprised there are not more painted and grained pieces in their collection.

The exhibit starts Feb 24, 2012 and runs through June 17, 2012.  I will be in New Orleans on April 5th through the 8th to do a lecture and workshop on traditional furniture finishes.  First time I will have been on an airplane in a dozen years, I think I will ship my tools and props so I don’t have problems with security, imagine what steel graining combs look like in a scanner?

Should be fun, never been to Louisiana.

Stephen

December 10, 2011

Unusual Characteristics of Wood

Filed under: Alchemy,Historical Material,Of Interest,Trees,Uncategorized — Stephen Shepherd @ 2:08 pm

Certain woods have unusual characteristics that are not widely known.  These are characteristics that are beyond the normal everyday usage of the wood.  These also include unusual ways that trees grow as well as folklore, myth and legend associated with certain woods.  While this information is not necessary for woodworking, a craftsman should be fully informed.

Wood that grows on the south side of trees (in the northern hemisphere) is more flexible and springy that wood which grows on the north side of the tree, which is harder and denser.  Under normal growing conditions the center of the tree is closer to the north side of the tree.  Trees are sugared on the south side of the tree and sap is removed for navel stores on the south side of the tree.  Under the largest branch also produces more sap.  A large Oak tree can transpire over a ton of water (250 gallons) in a single day.

While Basswood is excellent for carving because of its uniform soft grain and its ability to deaden sound and used in musical instruments, it also can be soaked in water and compressed to about half its size, it will spring back to its original shape when it dries.  Used to make puzzles where one piece of wood is placed through another piece of wood without any trickery except its ability to be compressed and forced through another piece of wood.

Most trees grow in relation to the seasons, the sap is up in the summer and down in the winter. Satinwood however grows to a different cycle, the sap rises on the full moon and drops on the new moon.  Perhaps this is why the wood is so full of minerals that contribute to the crystalline look of this beautiful wood.  In the fall, the Ginkgo biloba, while a primitive gymnosperm from China, can loose all of its fan shaped leaves in as little as 30 minutes.

Both Ash and Walnut (which are related) have collapsible pith at the center of their branches and were used by the Native Americans to make pipe stems.  A grub was put in one end and allowed to eat its way through the soft pith to the other end.  A hot wire can easily clear the pith from the center of the branch.  Black Ash trees can be pounded while the wood is still green and this pounding loosens layers of wood used for baskets and chair seat bottoms.  The open ring porous part of the wood (springwood) is crushed and the layer of solid wood (summerwood) comes off in thin layers, which are scraped and formed into strips for weaving.

Cherry produces the sweetest fruit but the inner bark of the tree contains concentrations of strychnine and is used medicinally for sore throats, coughs and as a stimulant.  The inner bark of Willow contains salicylic acid, which at the turn of the twentieth century was used to synthesize modern aspirin.  A branch of willow will keep mold from growing in the glue pot.  The bark of Cork Oak (Quercus suber) is periodically harvested every four to seven years without harming the tree for making of all things, cork.  The best comes from Portugal; the finest quality cork comes from 2nd, 3rd and subsequent harvests.  The bark is thicker on the north side of a tree.  The root of the Spruce tree is used to flavor ‘root beer’ and is used as cordage by the Native Americans for lashing canoes and other bark utensils.  The bark from the roots of Sassafras makes a delicious tea, is a blood thinner and a tonic.  You can rub the ‘nut’ of the buckeye on joints to alleviate pain.  The shavings of Osage Orange can be used as a dye for lightwoods or textiles.

The largest tree on earth is the Giant Sequoia, the largest living thing on earth is the Aspen tree and the oldest living tree on earth is the diminutive Bristlecone Pine that can grow more than 5000 years if not accidentally cut down.  When trying to determine the age of these trees, scientists did a core sample of what they thought was the oldest tree in a stand in the West.  At 4600 years, they thought it was the oldest, so they cut down a smaller one nearby to do a ring study, that tree was over 5000 years old.

Some trees such as lodge pole pine, jack pine and limber pine requires fire to scarify the seeds for proper germination.  Controlling natural fires have caused a decline in propagation.  The aspen is a short-lived nurse tree for evergreens and for the same reasons the total number of individual examples are dwindling.  If you have seen one aspen tree you have seen them all.  Every aspen on earth are genetically identical with every other aspen.

Coppice (also called copse) is a thicket or scrub forest originating from root growth, stump sprouts and suckers.  Climax forest is old growth at its maximum maturity and called original growth, virgin forest or wildwood.  Previously logged areas that have re-grown is second growth and because of the more open growing conditions the wood will have wider rings that the old growth which competed for nutrients.  A weald is an English term for a heavily wooded area.  Arboreal, Alburnam and sylvan are terms used to describe anything relating to trees.  Sylvan or Silvan is a spirit that frequents the forest.  ‘Wood’ is an Old English term for being insane or mad.  If you are ‘out of the woods’ you are free from danger.  If someone is a ‘chip off the old block’ they resemble their parents, as does ‘that acorn didn’t fall far from the oak tree’.  If someone has ‘a chip on their shoulder’ they are ready for a confrontation.  A ‘woodenhead’ or ‘blockhead’ is a numskull.  ‘Timber’ can be used as a noun to describe growing trees and as an interjection to describe trees being cut down.  A person can ‘lumber’ along or be ‘lumbered’ with burdens.  You can ‘board’ a ship made of boards on a gangplank.  With all members ‘on board’ the ‘board’ met in the ‘boardroom’ and agreed ‘across the board’.  ‘Springboard, sideboard, buckboard, blackboard, bulletin board, dart board, dough board, cutting board, game board, dashboard, backboard, headboard, footboard, centerboard, bundling board and board like.  One can ‘leaf’ through a book or ‘needle’ an opponent.  Trees and other vascular plants produce most of the oxygen made on this planet.  Dryads are wood nymphs and Druids are ancient Celts with a fondness for oak trees.  The word ‘wood’ can mean the place where the tree grows, the very material itself or something made out of wood.  And no one ever wants to be taken to the woodshed.  How far can you walk into the forest?  Only halfway, then you are walking out of the forest.  If a tree falls in the forest and no one is there to hear it, does it make a noise?  Of course it does, it will make a physical noise or sound but not a perceived sound.  If you walk around a tree, and there is a squirrel on the other side of the tree and it remains out of site on the backside as you walk around the tree, do you walk around the squirrel or not?  ‘Knock on wood’ or ‘touch wood’ is a superstition intended to bring luck or at least ward off bad luck.  While its origins are obscure it appears that it has to do with the spirits inhabiting sacred trees such as the holly, ash or oak.

There are about 100,000 species of Hardwood commercially available in the world today.  There are about 700 species on North America and about 100 species of Conifers on this continent.

Phrases relating to wood and trees:

A real log jamb.
A walk in the woods.
As the twig is inclined so the tree is bent.
Augers well.
Barking up the wrong tree.
Can’t see the forest for the trees.
Cash on the barrelhead.
Chip of the old block.
Chip on the shoulder.
Dull as a froe.
Fall off the wagon.
Get on the bandwagon.
Going against the grain.
Hammer it out.
Knock on wood.
Lock, stock and barrel.
Neck of the woods.
Out of the woods.
Out on a limb.
Over a barrel.
Sleep like a log.
Sleep tight.
Square peg in a round hole.
Squeaky wheel gets the grease.
Stiff as a board.
That acorn didn’t fall far from the oak.
That old saw.
Top drawer
Touch wood.
Turn the table.
Walk the plank

 

Stephen

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