Full Chisel Blog

June 29, 2008

Beating a Saw with a Hammer

Filed under: Sawing,Techniques,Uncategorized — Stephen Shepherd @ 5:47 pm

No this is not when you take the hammer away from a child because they are making noise by pounding on a hand saw but the purposeful hammering of a saw blade in order to straighten it out.

Hammering was done on new (19th century new) saws once they were made and prepared for sharpening.  Hammering was done to ‘tension’ the saw blades during the manufacturing process and work hardens the blade but allows it to remain flexible.  And of course hammering is done to old saws that are bent to straighten out a bent or kinked blade.  Badly bent or kinked blades that have cracked or fractured the steel of course the hammering will not repair that condition (I am not sure it is possible to repair).

Old blades should be cleaned of rust and brought to as ‘bright’ a condition as possible in order to have a reflective and smooth surface on the saw.  Bright tools tend to resist rust.  Once it is cleaned, it is time to examine the blade, which I do by sighting down the back of the blade.  This also applies to backed saws, sight down the back to see if there are any kinks, bends, bows, cups or curves.

 Some hammer saws on a metal anvil, and small saw anvils do exist, I however choose to use a wooden anvil with a slightly different technique.  I do have a metal plate that I use occasionally but for the most part it is on top of my chopping stump, a large squared timber cut off at about 34 inches tall, which I use for a variety of uses.

I always straighten out the back of the saw first, as this will usually straighten out the entire blade, depending on the bends and kinks.  I hold the saw with the blade straight up and down (the handle) with the back of the saw roughly parallel with the earth.  Thus by sighting down the back you should be able to see any problems with the blade.  Note where the bends are and place the blade down on the ‘anvil’ with the convex side of the blade up.  In other words the bump or kink is bulging up from the anvil.

S&J Bent

Planishing hammers with a slightly rounded face is the best, I use a small tinners hammer with a slight belly to its face.  It should be a round face to prevent denting, I however use a square faced hammer that I like and it has a slightly convex face (belly).  I am comfortable using these smaller hammers and have straightened dozens and dozens of hand saws.  I can never resist an old saw for $2.00, and rarely pay more than $10.00.  I am careful in my hammering not to go too fast and that my blows are deliberate and controlled so as not to dent the saw while attempting to remove dents.

A few ‘well placed’ blows with the hammer on the bulge, then I check the back of the saw again by picking it up holding it the same and sighting down the back again to check the progress.  I do this after every 3 to 6 strikes with the hammer.  Later I will check the saw after each blow when things are getting straight.  Now what is a ‘well placed’ strike?  That might be difficult to explain as I think it comes from experience.  Now different saws will behave differently, some straighten easily while others tend to need more attention.  I avoid striking on the very back edge of the saw (and of course I avoid hitting the teeth when working near them).

Hammering pattern

This illustration shows the pattern in which I strike the saw with the hammer, on a wooden anvil.

I hammer in a square pattern of a couple of blows next to each other near the back edge of the saw, then a couple just below.  I avoid striking the saw in the same place (unless I am working on a dimple or small bulge) but spread the blows around to prevent ‘popping’ of the blade.  That is when a dent reverses direction when struck with a hammer.  These can be tricky and may require more attention to get things flat.

S&J Straight

This saw was difficult to photograph, but the blade is now straight on both the back and the business side.  It had a significant kink and other minor bends, but it took less than 40 hammer strikes to straighten out the blade.  When striking the saw make sure it is laying as flat as possible on the anvil, this can be difficult with a bad bend.  I can tell when a blow from the hammer does something as it ‘sounds’ more solid when struck.  If it makes a bit of a ‘ringing sound’ then the blow probably didn’t do anything, it is when the blow ‘sounds solid’, that work is done.

I should mention that there are other methods for straightening metal by considering that the hammer blow will expand the metal on one side, so the work is done on the reverse side of the above mentioned technique.  This particular method requires a metal anvil as the idea is to expand the metal by hammering.  I have had some success with this method on other bent metal items, but I do not use it for saws.

I think that a craftsman should be familiar with their tools and know as much as possible about all things involved.  The study of metallurgy, of geometry, of physics, of chemistry, of morphology, the macroscopic and even microscopic study can add to the arsenal of knowledge and understanding.    Expose yourself to as much learning as you can, question experts and continue the quest, don’t limit yourself.  Like Mark Twain said, ‘Don’t let Schooling interfere with your Education”

Stephen

June 28, 2008

Price of Iron and Steel in the Nineteenth Century

Filed under: Laid Steel Tools — Stephen Shepherd @ 8:55 pm

After the recent comment made by Matt on Laid Steel Blades giving the value of steel as being 5 times that of iron at the time of the American Civil war, got me to thinking, and you know where that can go.  I realized at that point that the price difference was not great enough to be of significance.  And as he pointed out the manufacturing costs add up.

Well a friend of mine, just today, gave me some information from a book published in 1868 or 1869 about the History of Industrial Production in America from 1610 to date.  I will get the title to quote it exactly, but knowing I am interested in the price of metals in the nineteenth century, gave me some facinating information.  (I am hoping I can scan the complete book).

He mentioned that they lamented in 1820 that the price had falled from $140.00 a ton for iron bar in 1818 to a price of between $100.00 and $120.00 a ton.  That means it dropped from $0.07 a pound to $0.05 to $0.06 a pound, if my math hasn’t failed me.  Now using the 5 times ratio, let me sharpen my pencil (Invented by a Conneticut cabinetmaker in 1822) that would mean:

In 1818 the price of Steel would be about $0.45 cents per pound.  By 1820 the cost of steel would have dropped to approximately $0.25 to $0.30 per pound.  The drop in price is from advancements in iron and steel manufacuring and competition.  So.

Let say a plane iron contains a half a pound of iron $0.03 and lets say the steel is 2 ounces (remember it is just a thin veneer of steel on the large wrought iron blade) at a cost of $0.0375.  Now I don’t do well with that new math but I think I got the numbers right.  So a plane iron might have $0.07 to a dimes worth of material, then the cost of charcoal (or green coal or coke) for forging, the three heats, the labor, if the blade was made of steel it would cost $0.15 in material, without the cost of laying on the steel.

The economy explaination just doesn’t hold (wait, that is just too gentle, the economy theory is just exactly wrong), they did not put the steel on in a thin veneer to save money (where is the savings?), they put it on because they could make superior blades, pure and simple, do the math.  (Lets not forget the smoking gun: the brine quench).  I have a friend that is a statisician and I am going to have him analyze some plane irons and chisels to determine the exact ratio of steel to iron in these tools.  I do believe I will have more to say on this particular subject in the future.

But, for right now I am just basking.

Stephen

June 26, 2008

Cross Cut Saw verses Rip Saw

Filed under: Dovetails,Sawing,Sharpening — Stephen Shepherd @ 7:44 am

The great debate, the endless questions, the historic evidence, the ideas and theories, the dilemma, rake, fleam angle, taper, belly, grip,  set, down to the saw bolts has been discussed where ever woodworkers gather and talk saws.

I will be discussing saw sharpening only briefly (if that is possible) as it is covered elsewhere including here.  I will talk of set (oh wait I did that part) but I am going to discuss whetting or side joining saws as the final and I believe important step in properly saw sharpening.  I will get to hammer straightening a bent blade which I should have done earlier but there is nothing I can do about it now.

A cross cut saw is used to cut across the grain of the wood and are sharpened like knife points to score then shear the fibers of the wood.

A rip or splitting saw is used to cut with the grain and are sharpened like chisel points (or little tiny plow plane blades) to excavate the wood from the groove.  Usually with fewer teeth per inch and larger gullets to remove the dross.

Now in order to blur the line a little, here is a RIP/CROSS CUT saw blade in a nineteenth century American pattern bow saw, curly hickory arms, maple handles, white oak stretcher and the walnut and mahogany toggle is inspired by Eric Sloane.  The blade is after one illustrated in Salaman.

Rip / Cross Cut Bow Saw

And while it may be difficult to see the blade is cranked at 90 degrees in the middle of the thin blade.  The portion on the right is sharpened rip and the portion on the left is sharpened rip.  I use this saw to remove the waste between the pins when finishing my dovetails (tails first, as I gang saw the tails).  It is surprisingly easy to use and astounds people when I demonstrate how it works.  It cuts (rips) down to the score line, then when the crank (with its tapered transition) is pushed it begins to cut (cross cut) to finish the removal.  Attention must be paid to the angles of the pins and sawing is done on the money side (the one that shows). 

Tooth count: the general reference for the coarseness of saws is TPI or teeth per inch.  Now there are PPI or points per inch and I don’t know why there is a difference, perhaps a saw maker could respond?  Rip saws usually have fewer teeth per inch with larger gullets to remove the dreck rapidly as is their want.  Cross cut have finer teeth and vary remarkably as do the teeth of rip saws.  And here is a general guideline (I avoided the use of the word rule), finer tooth patterns are for thinner boards and coarser tooth patterns are for thicker wood.  This helps eliminate the saw dust easily.  Fine toothed saws, either rip or cross cut will tend to bind up on thicker boards.  Finer teeth produce finer cuts and are more suitable for thin pieces of wood.

Some blades are taper ground with the teeth being the thickest and the back being thinner.  This helps reduce binding and allows for little or no set to the blade and still cut and not bind.  Some open hand saws are tapered in the same way but also tapered to be thinner at the tip and tapering to thicker at the handle.  This of course makes the nicker nib nice and thin and capable of breaking off.  (It is easily filed back into the tip of the blade).  That nib works just fine, it doesn’t need to be as wide as the teeth, all it needs to do is make that fine nick on the edge of the board to start the cut. 

And the reason for the blades being wider at the handle or heel and narrower at the toe?  Because you can use the narrow toe to correct any errors in sawing as the narrower tip allows for correction to an arrant saw kerf.  Like a narrower blade can make a tighter circle, a narrower part of a blade can do the same thing.

And apparently not all saw were provided straight as many had bellies (breasted) with the teeth being higher in the center.  Now I am not talking those floor or veneer saws but open hand saws, cabinet and panel saws (maybe there is a distinction there).  And the P.S. Stubbs blade I have, albeit a web blade has a belly.  I am not sure it could be called breasted because the entire blade as a belly (convex), the back being slightly concave.

And of course there are those progressive toothed saws, finer at the tip and coarser over the rest of the blade, this is to assist in starting the cut after using the nicker nib.

And there are examples of both cross cut and rip in open and framed.  The open saw is lighter in weight but can have a much thicker blade than a framed saw.  The frame saw has the advantage of using thin and narrow blades for certain applications like cutting curves, they can also be used to hold thin and wider rip blades for splitting boards with a thin kerf.  The disadvantages of framed saws are weight (which isn’t that much of a disadvantage) and most importantly limited cutting because of the frame.  At some point, unless ripping off the edge of a board the frame will get in the way.

The advantage of the open saw is that it has no frame (and no back) so it can cut through pieces of wood that could not easily be done with a frame saw.  Speaking of back saws, as many of you know I am not a big fan of backed saws, I am down to only one very small brass backed Gent’s Saw that I use for fine work.  Larger back saws have always felt awkward in my hands and I never found one I liked, and I have gone through a couple dozen.  I think this is another marketing ploy by manufacturers, ‘a thinner saw kerf’, I think less saw, more money.  Why would anyone in the nineteenth century worried about the size of the kerf?  Ok, marquetry, but that is a different saw.

When I saw dovetails, I use my widest (kerf) unbacked dovetail saw, the more wood I can saw out the less I have to remove with a chisel.  If I did finer work, maybe I would want a thinner saw.  But my dovetail saws are all used for general purpose ripping of small pieces, I grab the big rip saw to rip the big boards.

Then there are the saws that need to cut both cross cut and rip, like a fine turning saw, compass saw, coping saw, fret saw, &c, how are these sharpened?  Half and half, the teeth are filed with the hook of a rip saw and the fleam or side angle of 80 degrees.

Stephen

June 25, 2008

There is an interesting discussion…

Filed under: Laid Steel Tools — Stephen Shepherd @ 1:27 pm

over on Roger Nixon’s site Traditional Tools and here is the link to the thread in a friendly exchange of ideas on Laid Steel Blades: Wiley, Wilbur & John Henry.

It is a great discussion with much information and I am sure it will continue.  I just had to post this and I will get back to saws momentarily.

Stephen

June 24, 2008

Saws

Filed under: Sawing,Sharpening,Uncategorized — Stephen Shepherd @ 10:00 pm

Now I would like to start at the beginning.  In the beginning God created… well this is not going to be a Michener novel, so saws go back a long way.  I have a knapped flint or agate blade that is serrated and will cut wood, it is a paleo-Indian artifact and is about 2 inches long.  Looks like 4 teeth per inch, I don’t know what the ppi is but it is close to 4.  I can not determine the set nor the rake nor the fleam angle but it does cut wood.  No markings or touchmark, but it is sharp, when I picked it up off the ground near Deadhorse Point in Southern Utah, I ran my finger over the blade (don’t try this at home) and turned that pretty translucent light brown stone, blood red.  I don’t do that anymore.

Shortly after the Stone Age, the Bronze Age produced some serrated bronze blades, the earliest are lost wax cast in a mess then sharpened.  The Egyptians had some specially hardened copper blades as well as hard bronze saws.  The first saws were crosscut, now someone tell me I am wrong.  It was too easy to split wood, saws were needed for crosscutting.  But things change and other types of saws were developed.  Saw developement in the Orient was early and dynamic and produced first quality tools as well. (That is an entirely other discussion which I have no real expertise).

It is hard to tell if the Egyptians split out their veneers, smoothed them and glued them down (with hide glue no doubt) then scraped or planed them down, or if they sawed them from baulks.  In which case they had rip saws.  Come to think of it I have seen hieroglyphic representation of a worker ripping a board.

Now on to the Iron Age and the introduction of iron, an ‘improvement’ over bronze and copper (although old techniques of hardening these metals has been lost).  And then the ability to control the carbon in iron gave way in about the 14th century to the advent of steel.

The Romans had saws, difficult to determine their configuration but they were certainly capable of cutting both cross grain and rip.  Saws also developed in the East, but I know little of these saws, Mercer makes comments on them.  It is interesting that Colonial Williamsburg uses only rip saws as these are those documented, I applaude them for keeping to tradition.  Being concerned with nineteenth century woodworking technology, I for one am happy to have a good crosscut.

English Bow Saw

I made two (well actually 3, I kept one) 17th century English style bow saws in white oak for Historic Plimoth Plantation and they were fitted with coarse cross cut blades as per their request.  They are bow saws not turning saws, the blades are fixed in one position.  Turning (bow) saws have handles capable of turning the saw blade to different angles, allowing it to be used as a rip saw, with proper configuration of the saw teeth.

There are at least two types of saws; crosscut, those meant to cut cross grain and cut boards or timbers to length.  Rip or splitting saws are meant to cut with the grain and along the length of the board.  Because it is so easy to split boards, cross cut saws outnumber rip saws in overall numbers (at least from my experience, gees I am getting defensive).

There are at least two type of saw holders, framed (like a bow or web saw) and open (handle on one end) and it is difficult to determine which was first.  Early cast bronze saws were open but most early saws were framed as the metal (iron and steel) was expensive and needed the tension of the frame to hold the thin blade taut.  With improvements in iron and steel manufacturing, more open saw were made and were usually much lighter as the frame was no longer necessary.

Of course the framed saw continued as it was an excellent way of holding narrow blades, allowing for curved cuts.  Frame saws, coping saws, fret saws, fellows saws, veneer saws, up down sash saw, are all of this type.

Stephen

June 22, 2008

Setting Teeth

Filed under: Sawing,Sharpening,Uncategorized — Stephen Shepherd @ 3:11 pm

Well, I have certainly opened up a topic here  (I wasn’t suggesting pulling teeth), I thought I would get more response on sharpening, but I am glad to get other opinions about the subject.

Now for exceptionally large saws, here is an exceptionally large saw set.  It is hand forged from an old file.  There is a wooden plug held in with a thin soft metal clip.  I am sure it is for large two man crosscut timber saws.

Large saw set

I don’t have a saw that big, but in case I ever do, I have the set for it.

Here is another one that has several adjustments but like the others does not ‘crush’ (my opinion) the tooth.

saw set

And another view showing the reversibility of the anvil (I am not sure which is the anvil, I think it is the pointy part with the thumbscrew on the bottom).

saw set

saw setNow these types of saw wrests do not ‘pinch’ or squeeze the tooth but just bend it a bit.

The important thing is to bend just the tip of the saw tooth, if you bend the whole tooth, there is a good chance of breaking the tooth at its root (this is a real term, not a joke).  And if one looks at good saws they do not have that much set and setting as far as saw sharpening is concerned is not encountered that often.  Some old blades are taper gound and have no set as the grinding relieves the blade, making the set unnecessary.

I don’t know what I am going to do when I talk about taper ground blades, because I have been putting my American Standard Wire Gauge on my old saw blades and there are multiple tapers in a given blade.  I hope others will provide input as to the reasons for these tapers.  And there must be reasons, as I am still convinced that our ancestors were not stupid and did things for a reason. 

Now of course a ground tapered blade (thicker at the tooth section and tapered thinner to the back of the saw), doesn’t require any set so this discussion does not apply.  And after checking the thickness of various parts of old blades on my saws, I see why I don’t use the saw set that much, no need.

Stephen

June 21, 2008

Setting Saw Teeth

Filed under: Sawing,Sharpening,Uncategorized — Stephen Shepherd @ 8:28 pm

Now this is a pointy issue and I have my opinions about saw tooth setting.   (This is spurred by a recent visit from an Old Tool Galoot from MN, an original Galoot I hear and it all started over some people talking about saw sets).  My favorite type is the most simple, a piece of metal shaped, drilled and cut with a hacksaw this type has small lead plugs (tin will work too) in the holes to protect the teeth of the saw.

Old Style Saw Wrest or Wrench

And here is one of my favorite styles, this one is a little fancy.

Saw Wrest

Saw Wrest

It has an adjustable and reversable stop for the proper tip to the teeth when making the set.  Although it is badly pitted, it is still a servicable tool, I need to replace those plugs.  The different slots for different thicknesses of saw blades.

Now this one is old so it is missing the little plugs of lead in each of the holes, which prevented the teeth of the saw from touching the saw set.

I have had several of this type and have made one that I use on a regular basis.  Well that is not true as I almost never set the teeth of the saw.  On rare occasion I will need to set some teeth, seldom all of them but on occasion I need to reduce the set of a tooth or two and these tools work well. 

I make all my small dovetail and detail saws and use traditional panel and cabinet saws in both rip (splitting) and crosscut.  When I sharpen these old saws the set seems to be good in most cases, some are trash and require retoothing and setting, but in most cases setting is not necessary.  And the set is not that much and of course after I sharpen the teeth I whet the sides of the saws, the last most important process in the sharpening process.

Well I have started in the middle of saw sharpening, I will need to go back to the beginning; hammering and straightening, joining, etc, etc.  But I wanted to talk about using saw wrests instead of saw plyers.  I think that the plyer type saw set crushes the tooth, work hardening them and causing problems.  The wrest will not crush the tooth and when properly used performs admirably.

 It takes some getting use to but once you get the feel (and all saws feel different) the right amount of force can be given to gently nudge the tooth into its proper place.  An accomplished saw sharpener can set the teeth of a saw quickly with this tool.

Stephen

June 20, 2008

Spring Cleaning

Filed under: Of Interest,Uncategorized — Stephen Shepherd @ 7:58 am

I had to get it done today as summer starts tomorrow.  So I am re-arranging my web log, with catagories (I figured that out finally) and I am going to change the look as soon as I feel comfortable doing that.

So far nothing seems to have crashed.  I have not gone through all my posts to get them in catagories, but I am about half finished with that task.

I also plan on redoing the blogroll with the same entries but better organized.

Thanks to everyone that gave me advice to do this, I wish I had known when I started this endevour.  I appologize for any inconvenience this may cause.

Stephen

June 19, 2008

Time to Slow Down and Smell the State Flower

Filed under: Of Interest,Uncategorized — Stephen Shepherd @ 8:37 pm

The Sego Lily, called the Mariposa Lily in California.  The pioneers are have said to survived by digging and eating the roots, a large corm that I have been told is quite delicious, although I wouldn’t know.  It is protected in Utah.

 Sego Lily

 When I went out to plant a heirloom tomatoe plant in the back 40 this morning, this had not yet opened.  Later when I went out to attend to the irrigation ditch, low and behold this rare little flower.  It will close up tonight and open again in the morning.

What is your state flower and how does it smell?

Stephen

June 18, 2008

1835 Cabinet Shop Inventory

Filed under: Historical Material,Uncategorized — Stephen Shepherd @ 2:39 pm

This is from Shelby County Indiana:

(do is ditto)

1835 Cabinet Shop Inventory

It appears to be a probate inventory of the entire household of a farmer/craftsman of the period.  This provides information of the (fair trade) value of items during the early nineteenth century.  These values will vary from prices charged for new items in the same time period, which usually are higher priced.

Stephen

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