I recently came into possession of two Disston D8 handsaws…rip and crosscut. They were in fair condition with some surface rust and pitting on the blade. I used steel wool to clean the blades.
Once the blades were clean, I began the process of sharpening the saws. I planed the blades, and shaped the teeth. Then…disaster. As I started to set the teeth, half of the teeth either snapped off or fractured at their base! (Yes…I did stop after seeing a trend.)
I’ve never seen teeth come off like this…what could be causing it? I have a theory and I wanted to see what the wisdom-of-the-ages here agreed.
Is it possible that the rust would have deteriorated the teeth to the point that they became brittle? The teeth, having the most surface area, would seem the most vulnerable to rust. If that’s the case, would it be possible to file off the current teeth and start over again with steel that is more sound?
Any thoughts would be appreciated!
Thanks in advance!
Cliff
Replies
Hi Cliff,
Is it safe to rule the possibility that you used your set incorrectly? It sounds as though you've done this before. Just out of curiosity, what is the pitch/tooth count and what style of set were you using?
Its possible the rust was deeper than you thought and it have weakened the teeth. But you would have felt that those teeth offered less resistance. I don't think rust would have made the teeth more brittle per se. Its been my experience that older saws are often more brittle than newer saws and I'm not sure that makes them better. This is one of the reasons why.
For anyone else, remember to set only the top third of each tooth and use gentle, slowly increasing pressure. I don't trust any set to deliver uniformity automatically. You must feel the same pressure in your grip on each tooth. I feel it important to set all a saw's teeth at once. Dont' do half then another half tomorrow.
Adam
Adam,
Thanks for the reply. I checked the set and it was correct. Even with the anvil set at a very slight pitch, some of the teeth would snap off. One even snapped below the gullett!
The saws have some sentimental value so I'd like to keep them and use them. Any hints on where I might send it to have new teeth cut?
Thanks again for your reply!
Cliff
I recently (the past month), sent an 8" saw to Cooke's in York, PA to be re-toothed and sharpened. It was originally about a 20 tooth pattern and I had it re-cut to 15 tooth rip. While it was there I told Steve to also sharpen it after re-toothing. Future touch-ups will be done be me. Saw began as a Freud (I believe, but it looks similar to any of a half dozen English full-handled similar saws). I made a new handle in the pattern of an old Disston I have, with an open handle angled slightly more upward.
Cost of the work and return postage was about $26.00. I stoned some of the set out of the saw, and know have another dovetail saw that cuts with the best of them. The saw had been lying around, unused in my shop for at least a decade, had Cooke's cost and a Sunday afternoon making the handle. As the blade is touched up by hand, the feel of the saw and resulting cut will seem all the more smoother (randomness of hand filing????).
T.Z.
The saws were ground with dull wheels.This caused the teeth to overheat and now break off. If the saw was filed instead of machine ground this would not happen. The teeth now have to be ground or filed flat and the saws retoothed. Probably not worth the effort.
mike
I don't follow. Wouldn't grinding with a dull tool create heat that would draw the temper and soften the steel? I always think that older saws may be harder just because they have work hardened.
Adam
I have an old Disston that I acquired for a rip saw. I sent it to a sharpener (company) that used a machine to punch new teeth into it and it broke in a few places b/c of this. They said it had become too hard - perhaps from extreme heat and thought it was trash.
I then sent it to someone in MD who does saw sharpening and he ground it flat again and cut the teeth in w/ a file and said some older saws were just harder than some but nothing was wrong with this one. I had it sharpened as a rip saw so I'm not sure if it has less set than others - and thus less chance of breaking teeth when setting it.
KD,
I have a relatively new (25-30 yrs old god I'm getting ancient) Pax brand saw, that I broke a few teeth off of when trying to add more set. I agree with Adam that the placement of the anvil of the sawset makes a difference...
Had my sharpener cut new teeth on it, which he did with no problems. It'd be quite a job, to file all the old teeth off, and file new ones on; easier to get a sharpening service to punch new ones, and file them sharp, imo.
If you are missing just a couple of teeth, you can use the saw as is, gradually filing in new ones as the saw needs touching up oveer the uyears. Many teeth missing, however will make the saw want to jump in the cut, aggravating. In my case, the teeth bothered my aesthetics, felt like I was looking at granny Clampett every time I picked that saw up!
Ray Pine
Cliff, I notice you say ''either snapped off or fractured at their base''- at their base? I suspect that you may not be using the saw setter tool correctly: possibly placing the anvil too low down on the tooth. It should be at a point no lower than half way down on an average 10tpi saw- better at slightly under half way.If you have an Eclipse type that you squeeze like pliars these are easy to work with.
It is also possible, (long shot), that someone may have used a de-rusting liquid in the past-some of these concoctions cause metal to become brittle-this happened to me when I used ''a chemical solution'' to de- rust some spring calipers: everything cleaned up and shining, but the spring plates that maintain tension simply shattered....How bendy are those saws?(;)
Thanks for the reply Philip.
I've got the anvil set to contact the top 1/3 of the tooth so I don't think that's a problem. It's just very strange to have the teeth when pressed on the top 1/3 snap off at the base! The metal seems to have become very brittle.
I'm also beginning to wonder if in the past, someone set the teeth at the base thus stressing them.
Thanks again!
Cliff
"I'm also beginning to wonder if in the past, someone set the teeth at the base thus stressing them."That could be. Stressing is the wrong term. A set "yields" the teeth. And absolutely the teeth will locally work harden there. Tell us again what set you are using? If you have a 42 X and its working correctly, you should NOT be stressing that portion of the teeth to even give them the opportunity to fracture.See what I'm thinking is if you joint off the teeth, you may have the problem reoccur. So spill your guts on exactly what you are doing, what set, how many teeth per inch etc.Adam
You wrote: "I planed the blades, and shaped the teeth."
What do you mean by the bolded sentence?
As well as the questions and advice already given, and just as general comments:
[1]...if one tries to set the teeth to the opposite side of how they were at one point in time, they probably will snap.
[2]...too much set and they might snap.
[3]...too much force squeezing the saw set and they might snap.
[4]...lifting up or a twist on the saw set while squeezing may cause the teeth to snap.
Probably more. And that's aside from other causes mentioned. Including the steel. No idea why some saws become hardened over time. But some do. In the not too distant past I retoothed pre-Seaton chest Kenyon backsaw [made prior to 1793]. Steel was great both punching and sharpening. I have also had Disstons in that were made around 1900 so brittle I wouldn't do them.
Take care, Mike
Mike:Are Disstons of that period prone to trouble? I have a pre 1917 one with a beautifully shaped very comfortable apple handle, but dull blade. Was about to send it out (yes, after our discussionf of s couple of weeks ago, I do plan to learn to sharpen, but a nice old saw like that is not the place to begin, IMO).So to why -- something in the steel -- alloy or treating. As you all know, steel is fickle stuff, and was generally speaking, less consistent in the pre-spectrograph days. These days, every melt is tested by the lab at various points before it is poured, and adjusted as to alloy -- or if that is not feasible, the metallurgist will either issue instructions for getting the right physical characteristics via heat treatment, forging, etc., or he will redlight the melt. At the turn of the century and befoe, the tools were just not there for this kind of accuracy.
Hi Joe,
No, I don't think prone would be a good word to use. Gotta remember that during that period, Disston was making literally millions of hand saws a year --making his own steel since the mid 1800s. I suspect if it was merely a "bad mix," far more saws would be affected.
My point, if I had one, is simply to say that age is not a great indicator of embrittled steel in a saw. A brittle saw plate is fairly easy to tell--try a Nicholson saw file on it. Brittle saw plate is hard and cheap Nicholson files don't like it.
I tend to believe that for saws after a given point in the history of steel, embrittlement in handsaw plates was done by users sometime during their lives. But grinding isn't one of the ways, unless one quenches the hot steel immediately. Plates which needed straightening--hammered on an anvil or other hard surface--is one possible explanation. At least for handsaws. Doubt too many backsaws were hammered. And I have seen and replaced many brittle backsaw plates.
Making a saw is not a gentle process. I doubt a saw with "bad" steel could go through such a process without evidencing problems.
While it is true that steel is a highly scientific enterprise these days, it wasn't alchemy then either. I look at tool steel making much like I do about furniture making--a lot of attention is paid to some ideal of perfection when not an absolute necessity.
Take care, Mike
Excellent points, Mike. Thanks for taking the time to give such a thorough answer.
Actually, even today, ordinary steel making is not as precise as my post may have implied. The nice thing about steel, as you know but our readers might not, is that there are multiple routes to the same end. Even if the alloy is off a few points, the physical characteristics can often be attained through treatment. And, the requirements for saws are not as demanding as some kinds of applications (bearings and other kinds of machine parts).
As I know from many nights of watching the furnaces and reading the lab reports, this ability to treat steel to get what you need has saved the bacon of many a foundary, because there are lots of ways to get inconsistent alloys.
You are undoubtedly right about later work hardening. I was just keying in on the idea that you had had multiple turn of the century Disstons, which might have argued that the steel in that period was at fault.
Joe
I really think Disston went out of his way to make harder saws for people who wouldn't, or couldn't sharpen their own. Disston was making saws for (or selling saws to) the masses of immigrants and farmers who didn't know how to use them or sharpen them. These were not necessarily disposable saws, but close to it. He optimized them for the unskilled user, much in the same way tools are today.He also probably increased the hardness of the skew backs and saws with the smaller plates (the ridiculous "light weight" saws). These were never meant for serious users. The ad copy is preposterous, obviously targeting numb-skulls.So I think this is just one more piece of evidence that my statements a while back were correct. Disston "dumbed down" saws for people who couldn't sharpen them and didn't know how to use them. Harder saws, and I'm starting to believe harder chisels, are for people who lack the means or ability to sharpen.Adam
Interesting, Adam, and while I wouldn't know, of course, it is certainly possible.
One question, though is why the early Disstons had such well carved handles. Later handles are clearly mass-produced, but those pre WW1 items took a lot of time. I kind of figured that was for the trade.
I would suggest, though that even if you are right, the farmer/immigrant market might not have been numbskulls, but rather just guys with limited needs for saws. They were farmers, shopkeepers, police officers, etc. Most of their needs would be carpentry, and carpentry itself a limited use of their time. Kind of like my need for plumbing tools and my ability to use them. I need to do the work every so often, but by no means know or need to know the trade.
And, framing carpenters used hand saws, too.
Of course, by cabinet-maker's standards, I am one of those numbskulls myself. I am a pretty fair carpenter for work that does not involve extended arches, curving stairs, eliptical domes, etc. But as I am learning, fine cabinet skills are really another world.
You, Mile, Samson and the others who are so generous with your time and so free with your advice to numbskulls like me are really shortening the learning curve.
Several, semi-random thoughts...springing off of Adam's sentiment:
Disston "dumbed down" saws for people who couldn't sharpen them and didn't know how to use them. Harder saws, and I'm starting to believe harder chisels, are for people who lack the means or ability to sharpen.
Before his death, Henry Disston lamented that it was getting harder to find a good mechanic [person using the saws] and that he both had to increase the rake and the set of his saws. It irked him. Most US makers followed suit.
No matter what the hype for a given saw in Disston's line-up, they all used the same steel. So the designations "Best" "London" and so forth were marketing babble. The main difference was in the amount of taper grinding and post-grinding polishing.
Cost-cutting for Disston and others first affected handles. The shapes were less refined over the years. After the depression, the amount of steel processing lessened as well. Still good steel for a long time, however. Atkins went from chip carving the wheat to stamping it into the handles fairly early.
Personal opinion here...as the market shifted from woodworkers to carpenters is when I think the saws changed the most. There's quite a difference cutting "pond dry" softwood and cabinet making wood. Too, there's quite a difference between site work and shop work.
However, I also think that the "bones" of the US saws remained quite nice for a really large span of time. And depending on how demanding one is of their saws, pre-Depression Disston/Peace/Atkins et al are good saws.
I think English makers held on to using heavier plates longer. At least some did. While not the best saws to choose if you are on-site cutting rafters to fit, a heavier handsaw for a given length is a great tool to use in the shop. Set and sharpened for the woods one uses, they are efficient tools.
Take care, Mike
Interesting about the steel. The handle shiftis really dramatic, just as you say. My turn-of-the-century Disston has a wonderful carved handle. Not too many years later, they were essentially just cutouts with the edges rounded.I wonder, Mike, if you of any of the others know when handle-making was mechanized? I collect avalry saddles and equipment, There is a major late 1890s change in approach to, and to a lesser extent design of McClellan saddle trees. What happened is that the Rock Island Arsenal got duplicating routers and started designing with the tool in mind. Did something similar happen with tool handles?BTW, did you note there is now a SAWS 4 thead?
Edited 4/1/2007 3:20 pm ET by Joe Sullivan
Hi Joe.
I know that Disston brought some of the first--if not the first--bandsaws into the US from France for more quickly cutting out handles. I suspect the pin routers and patterns were shortly thereafter once the benefits of speeding up production were apparent.
It isn't so much the routers or shapers which dictated the shapes. At least not at first. I suspect it was getting away from hand work which still followed the machines which was the biggest shift in design changes.
I say that because the first new wave of DT/carcass saws as made by Taran [Independence Tool Company] were roughed out using a 3 or 4 axis carver, followed by hand work. His company was sold to LN. What LN now uses I do not know. Point being that the handles Taran made were nicely shaped even though machinery was used.
Take care, Mike
Interesting. Of course, a multi-axis machine today can be a lot more subtle than a router 100 years ago. More handwork then, no doubt.
Whatever, the case, the Disston handles sure declined as the 20th century progressed.
J
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