A dovetail saw question

[steven c newman]

I was watching a show one time, showing how the craftsman down in Colonial Williamsburg would sharpen their dovetail saws. It seems that they wanted a saw without any "wobble" in a kerf. They would take a freshly sharpened saw and rub the teeth across a whetstone. They would remove some of the "set" this way. The "proof" of a good saw to them was whenin a cut, one could let go of the saw, and it would stay put. They claim it made for a finer kerf. Anyone else hear of this technique?

[Roger Benton]

That makes sense. I've heard of stoning one side of the teeth to reduce a tendency to wander.

It seems like success with this technique requires a very well developed feel for the tool.

[mike holden]

Steven,
this is a ripsaw without set. Works fine till the teeth fill with sawdust, then you have to remove the saw, remove the sawdust, then put the saw back and continue. This often works on dovetails as the cut is not deep nor is the material thick, so the teeth can get clean when they pass out of the wood.
Disadvantage is that the saw cannot be steered, once you begin your cut, that is the line it is on, period. (well, you can fudge a very slight amount, but not much) Means you have to hit your lines perfectly. Takes a good sawyer.
Also, when trying to make adjustments, it is easy to bend the sawplate and ruin a good saw.
If you are making, or reteething, your own, then dont put any set in the teeth. If you are starting with a commercial saw, then stoning both sides to remove the set is the time-honored way to go. If you are ordering a custom saw (Wenzloff, Adria, etc.) order it without set. You can always add set later if you dont like the results.

One last thing, remember that the folks at the Hays shop speak only of the methods known to be used at that time, in that shop, any later improvements are "unknown" to them as they have not happened yet. (they do a really good job of staying "in period") So, the way they do things works, but may not be the best. For instance, all their saws are filed rip, because there is no evidence that crosscut saws were used in the Hay shop, even though crosscut saws were known in that time frame.

Mike

[Jim Koepke]

They probably didn't cut any dovetails in pine that is either still a little damp or has a lot of pitch. There are times when even a saw with too much set will stall or get stuck in a cut. Some of my wood seems to swell as it is being cut. Using a coarser saw sometimes helps.

jim

[Carl Maeda-San Diego]

I have always taken out all the set from my dovetail saw and yes, you have to start your cut carefully but the kerf you leave is straight. I haven't had any problems with pine or any other material but I have never tried to cut dovetails in green wood but I have cut dovetails in air dried wood.

[george wilson]

We made the saws used in the historic area in Williamsburg in the tool maker's shop. Jay Gaynor thought that the saws were all filed rip early on,but when I examined the unused saws (NOS) in the Seaton Chest,it seemed to me that the crosscut saws were actually filed at about a 10 degree angle,or about 1/2 of the angle that crosscut saws are filed today. Like everything else,things seem so evolutionary.

Those old Kenyon saws were hard to see the teeth on,as they were quite dark,but with a good close look,I could see that they did have some angle on their teeth. It is really hard to determine exactly what was done in the 18th.C. on saw teeth. I suspect,like everything else,the tools were supplied with teeth on them,but they may have been filed in,ready for the USER to finish up. Many things,like carving tools,were supplied without handles,and just roughly ground. The user was expected to know how to finish up his tools. The makers were very "thrifty" back then.

At first we did file rip teeth on our saws as per Jay's suggestion,but they didn't cut as well as they might if filed more acutely. I was usually not doing the research,just the making of tools,based on what I was told to do,but I did examine the old saws,and observed that there was,as said,about a 10 degree angle in those saws,so changed my ways.

The Hays shop was the only shop in the historic area who sharpened their own saws. All the rest sent their saws to us to be re sharpened. My old journeyman,Marcus Hansen,was the one in the Hays shop who re sharpened their saws,but he had been trained by me back when I was the musical instrument maker. I'm not saying that he might not have picked up instruction from Mack Headley,who was then his Master.

Personally,I never stoned the teeth down. I just squeezed the teeth down in a smooth jawed machinist's vise to remove some of the set,and to smooth out the set in the teeth. I do not really like the idea of stoning the sides of the teeth. I think that doing this makes flat spots on them that are parallel to the direction of the cut,and causes the teeth to rub,somewhat. This is just my own thought.

We did file dovetail saws rip,as they do cut with the grain. Some of my favorite dovetail saws had nearly no set.

The men who made their own marquetry saw blades from watch springs did not set the tiny teeth. They just left the "rag" of the file on the teeth to act as a slight set.

[David Weaver]

On my combination dozukis, I always run them two swipes across a bester 1200 stone. Two light swipes, light pressure and care to make sure all of the teeth travel the length of the stone.

Same with a saw that is for dovetailing only, but western. Obviously, if you stone the teeth nearly flat and out of set, if you go beyond 3/4ths of an inch or so, you start to notice the pressure on the side of the saw. You can wax it, but that's probably not what you want to do in dovetail long grain.

I also put a little fleam on the only western saw that I use for dovetails - it cuts very close to as fast, starts easier and leaves a nicer finish.

[Stanley Covington]

This is a valid and historical method for correcting a saw that has too much set, and tends to drift. It is also a good way to remove excess set from Japanese replaceable-blade dozuki saws. Down side is that it shortens the life of the saw. In the case of induction hardened replaceable blades however, it is the only choice. A hard arkansas stone works best in my experience.

Think for a minute about what happens to the grit from the stone. Some of it gets stuck in the teeth, then embedded in the kerf, and then dulls the following teeth. Best to rinse the teeth with the solvent and brush them good with a toothbrush to remove the grit before cutting anything.

Stan

[Jim Koepke]

Personally,I never stoned the teeth down.

George,
I am curious about one detail. When you file teeth, do you file the tooth with the set toward you or away from you?

TIA

jim

[Don Dorn]

Very interesting thread -allot of knowledge here. The hope of being here is to learn something, and I'm definately getting that in this thread.

[george wilson]

I file with the set away from me,so the file doesn't chatter.

[Jim Koepke]

I file with the set away from me,so the file doesn't chatter.

George,

Thanks for your reply.

I am quite sure your experience and skills at saw sharpening are much better than mine.

When I file with the set away, there is a little bit of metal pushed over the side of the tooth. When stoning the sides of the teeth, it is this and only this that I am trying to remove. Maybe as my skill improves I will be able to avoid this.

I do agree with you about stoning changing the quality of the cut. I have not done a lot on this, but there are polished streaks on the cut piece of wood and it is my thought that these maybe caused by a tooth or a few teeth being flat on the sides. When looking at the cut piece, these can be seen repeating in the cut.

It seems there is always something else that needs being done before I can get around to spending time to analyze the effects of saw teeth in a kerf.

jim

[steven c newman]

sometimes are better than having a tooth or two sticking out, cutting a groove in the side of a cut.

[David Keller NC]

There is yet another means of removing some of the set from a saw that was elaborated on by Mike Wenzloff a while back - I cannot remember whether it was on this forum or the SAPFM forum (which anyone can view regardless of whether you're a SAPFM member or not).

Essentially, he described taking a small, lightweight brass hammer and lightly tapping down the toothline of one side of a saw and then the other, with the saw resting on a hard maple block as an anvil.

I tried this technique with an antique that had an incredible (and inappropriate) amount of set, and it really worked well.