Full Chisel Blog

July 24, 2009

Turning, Sanding and Sharpening

After examining many old turned objects, be it spindles, finials, legs, stretchers, split columns, etc., I have come to the conclusion that turning just isn’t the same today as it was in the past.

A couple of things emerge; first the nature of the finish of many turnings and the much different tools illustrated in old trade publications, catalogues, etc.  I find little or no evidence of the use of sanding as a finishing step to smoothing turnings.  Gouge lines, chatter and a clear not fuzzy look to the surface is one indication.

Another is the crisp detail left by a sharp tool as contrasted to pieces that have been sanded.  I do sand to finish on occasion, mostly to match worn details on repair or restoration projects.  And while reproducing old work I tend to do what the originating craftsman did and sanding seldom shows on old work.

The second divergence from turning practices of the past is the variety of turning tools available back then.  Granted, many are for ornamental turning and scraping ebony, lignum vitae and ivory, why aren’t there any being reproduced today?  Today we may think we have many more choices than ever, but that just isn’t the case.

Even with the large choice of tools, it appear that many turned pieces that only one maybe two tools are used.  I am of the opinion that straight chisels were the most common used tools, especially the skew.  Gouges are more expensive than chisels and more difficult to sharpen.  Consider Moxon’s description of straighting out hook turning tools, sharpening them then re-bending them to their original shape.

 Sharpening turning tools today is much different.  Also the old tools have better quality metals and required less sharpening attention.  At the first sign of dullness, many today go immediately to the complex sharpening systems/stations.  I can not say for certain, but I think sharpening is overdone and over rated today.

Sanding turnings, is another modern remedy for lack of turning skills.  Abrasive removal of material during turning was done in the past.  Sandpaper in one form or another was around since the mid nineteenth century but it was expensive. 

Other materials like horsetails were collected, prepared and used to smooth both wood, bone and ivory and metals.  The stuff will scratch even a hard steel file.

Pumice and rottenstone are powdered abrasives, solid pumice such as holy-stones were used for cleaning and smoothing ships decks and wooden floors.

Ell skin and shark skin, especially dogfish skin are good abrasives, flexible and work in only one direction.  Perhaps the most unusual abrasive material was also used as grips on swords, handles on cutlery, etc. and that material is shagreen from sting-ray skins.

The material is unique in that it has mineral deposits spread over the rays on the upper back side of the skin, the belly skin is smooth.  The tubercules of mineral deposits graduate from fine on the edge to more coarse near the spin or backbone of the fish.

Commercially available ray skins are polished smooth after dyeing the skins usually green, hence shagreen, brown, black, gray and other colors.  The interest to the woodworker or turner is the minerals on the skin.  These can be roughened up with abrasives to produce an abrasive surface that is very durable.

It can be left smooth to act as a burnisher, which I believe was used extensively in the nineteenth century and earlier.  And while I may be repeating myself from the last post, this material is important enough to talk about again.

A turning process called ‘boning’ was done with burnishers made of a large animal bone.  Worked smooth and polished bone burnishers are handy tools for making a surface glass smooth.  Boning can also be done with any other material that is harder than the surface being turned.  Burnishing or boning is also done to woodwork other than turnings.

   

These are some bone folders that I have made.  They are in the white but will get some color.  I have also not buffed them to a high gloss, but that just takes a few minutes with my hand buffer.  I have several bone burnishers that I use on a regular basis, these are a little fancier but still see service burnishing.

Another method of getting a smooth surface is to raise the grain.  I do this on everything I make to insure that the raised grain will never happen again.  I do this on all my turnings as well.  I get it wet, raise all the grain and allow it to dry completely.  I then smooth it again and burnish or bone.

A great deal of stuff was turned while green or at least air dried.  Kiln dried wood is harder and more brittle than its air dried counterpart.  Once wood is heated above 185 degrees, fatty acids in the lignin irreversibly harden making the wood hard and brittle.  So green or air dried woods are much easier on tools than modern kiln dried woods.

Stephen

5 Comments »

  1. Stephen,

    I am looking forward to some tutelage on the working of bone.
    Thought you’d be interested that the NY Times travel section has some info on your area and former employer:
    http://travel.nytimes.com/2009/07/24/travel/escapes/24amer.html?hpw

    Regards,
    Mike

    Comment by mike hamilton — July 24, 2009 @ 1:27 pm

  2. Good article. This is new stuff to me.

    What kind of bone are we talking about? I would guess that modern agriculture would produce feedlot animals with softer bones than wild or range fed animals.

    Comment by Luke Townsley — July 25, 2009 @ 9:56 am

  3. Mike,

    I will do something on bone in the future, and thanks for the heads up on that article.

    Luke,

    I am sure it is from a slaughter house in China. The blanks are commercially available bone folders I get at a good price then rework them to this shape. I also get some bone roach spreaders, for Native American head dress that are a bit wider and somewhat shorter than the folders. They are cheap too and not as strongly bleached as the bone folders. I am not sure about feed lot v wild range difference, interesting thing to consider.

    Stephen

    Comment by Stephen Shepherd — July 26, 2009 @ 6:15 pm

  4. Great post, I really enjoyed reading it. I do disagree on a couple of points,
    “Also the old tools have better quality metals and required less sharpening attention.” We have an immense range of metals to choose from these days, we can choose a metal for every type of wood and cutting technique and all of these metals are exactly reproducible. It is just a matter of matching metal to tool use. There are also some fantastic old tools and I have some, for example Gilpin and Whitehouse tools are a joy to use, but I also can easily buy fantastic new tools. Yes, I think we can become a bit OTT about sharpening and the plethora of systems, we did not have so much choice in the past, we just got on with it.

    I find it very hard to believe that many turners of old straightened out their hook tools to sharpen them, bowls of all sorts of sizes and shapes were turned out one after the other, and were everyday ware for many many centuries over here in the UK. Could he be referring to doing this when the tool was used and sharpened so much that a new tip or hook needed to be made? Is any of Moxons writings available on the web?

    I am interested in traditional abrasives and would like to know more, for example how do you prepare marestail so you can abrade with it. I am trying to get people to stop sanding there spoons and if they want them smooth to scrape, and then burnish them. It was interesting to read about bones for burnishing as my dad used them in his leather work, I will have find some bones and make my own now. I like seeing the tool marks on wood, and often find it adds to the aesthetics of the artefact, again we have become as a society obsessed with the plastic smooth and gloss finish, it has its place but not to the extent we see today.

    I do use kiln dried wood and yes it is more brittle, but are you sure it is irreversible. I say this because I have made many fan birds from kiln dried ash which I have boiled and then soaked for a couple of days before riving and making the fans. All the information has said this is not possible and can not be done, but I have! Still I prefer to use green wood any day, as you say it is easier on the tools and kinder on the body when working them. Sean

    Comment by Sean Hellman — July 28, 2009 @ 11:05 am

  5. Sean,

    Well I will comment on both posts to which you commented. I also think the hardening techniques of the past coupled with laid steel blades lead to better tools. As for what is available Moxon on CD from Gary Roberts has all sections including Blacksmithing and Turning. I am just reporting what he observed.

    To prepare Horsetails or marestails or joint-grass or Equisetum is to collect them and separate them at the joint. Then dry them in the dark, this gets rid of the green chlorophyll. After they are dry, they are then soaked in water (I add a few drops of glycerin to keep it flexible), split them end to end and flatten them out to use as small rectangular sheets. The larger the horsetails in diameter the larger the sheets will be.

    Your work with kiln dried wood for your fan birds, you are softening them by boiling, the heat and water makes the wood flexible enough for your work. Once it has dried is is still more brittle than if you did the same with air dried wood.

    Stephen

    Comment by Stephen Shepherd — July 28, 2009 @ 11:42 am

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