Saw Sharpening Equipment Changes

It’s been saw season around here lately. A few months ago, Lee Valley introduced their saw filing holder (or as I like to call it, “a doo-hickey that you put on the end of the file”). I bought one almost as soon as it came out. Unfortunately, an injury to my finger (not induced by woodworking) and other matters have kept me from doing much in the shop this year. However, I did get a chance recently and because I had a number of saws that needed help, I thought I’d start there.

Strangely, the last thing I did in the shop in the previous year was also to sharpen a pair of saws that ended up in Ethan’s workshop in Taiwan. I did those with the old “block of wood on the end of the file” method. For those, I also made myself a quick-and-dirty saw jointer:

saw_jointer

This is another one of those things I should have done a long time ago. It took maybe 20 minutes.

Now, the only real reason that I bought the Veritas holder was being fed up with the million little saw file blocks that accumulate over time:

saw_filing_blocks

Not only do those blocks take up a lot of space when I’m not using them, but it’s hard to keep the angles consistent on both sides, and trying to keep track of them all is irritating.

The first saw I worked on was a small crosscut saw for a friend. I said that I would do this saw last year and thought I’d better get it out of my queue first. This saw also featured another first: The first time I ever hammered out a kink in a saw. I’m amazed that it worked. Then I jointed and shaped the teeth. The shaping was the first time I used the handle, and because I just used it straight across to establish a halfway decent tooth geometry, there isn’t much to write about other than that it seemed reasonably comfortable.

Then I set the teeth. Here’s another departure from the norm. I’ve been using a Millers Falls saw set for a long time, and although it works fine, it’s a little uncomfortable to use for a long period. I thought about a replacement such as the famed Stanley 42X, but that has the same kind of grip as the MF. For whatever reason, I decided that I’d try to figure out a Disston Triumph saw set (Stephen Shepherd has written about them here):

setting_with_disston_triumph

It turns out that these things are not bad at all. It’s got the height and depth adjustments that you want on a set, and has a little “gripper” to grab the saw plate just before the plunger presses the tooth into the anvil. One size doesn’t seem to fit all, though; the plunger on the one I have is much too wide for fine-tooth saws (there are smaller versions, and I think you could file down the plunger, too).

With the set done, I could apply a final light jointing, and sharpen the teeth:

filing_with_veritas_handle

The Veritas handle was still reasonably comfortable, but now that I was filing to create fleam and sloped gullets, I noticed that the rake angle setting on the handle was really no longer realistic (the protractor that sets the fleam angle guide was slightly better, but read on). So instead of trying to figure out the correct angle, I just placed the file in the gullet with the fleam and slope that I wanted, and rotated the rake angle setting until the protractor guide was parallel to the saw. However, I did take note of the rake angle setting that resulted on the file holder, because I reversed it when I filed the second half of the teeth from the other side.

The resulting saw worked as well as any I’ve filed before:

de_saw

Of course, it only worked well once I glued the beautiful apple handle back together after I’d cracked it trying to take the picture above (sigh).

The next saw to work on was a new rip saw that I had on my list for a while. A while back, I had found yet another Disston No. 7 with quite a lot of blade left (but not in the greatest of shape rust-wise). After removing the rust and waxing the blade, I set about making the large teeth by removing every other tooth, converting a 7TPI saw into a 3.5TPI saw. I was a little worried about setting this saw, because I might be trying to bend every other back against its original set, and that could break a tooth. But it turned out that once I’d filed out all of the new teeth, there wasn’t much set remaining anyway, so it worked out fine:

cutting_new_rip_teeth

It was during the filing of this saw that I determined that the Veritas handle was helping me file a little faster. This had nothing to do with the angle adjustments. It was because I could pull the file with my left hand as I was pushing with my right. This was possible because the file holder grips the file tightly (as opposed to the block of wood, which does not). It made a difference on this saw because there really was quite a lot to file away to create the new teeth.

But I also determined that you really do have to take the measurements on the saw file holder with a grain of salt and make adjustments as necessary. The large teeth on this saw require a large file, and this is what it looks like when the file holder is on the end:

veritas_handle_on_big_file

Because there’s an increased taper at the end of the file, the file holder grips slightly askew from the file’s line. So if you want to keep this file perpendicular to the saw plate by using the protractor, you have to adjust the protractor off the zero mark. There is less of an effect on smaller files, but it’s still there.

In the end, I don’t think this matters much. It would be a tricky (but not impossible) engineering problem to fix it, but the worst part would be an additional adjustment on the handle that would be far more confusing than the ones already there.

The third saw that I filed was my Winchester crosscut saw. I did not need to shape the teeth because I wasn’t starting from scratch. I lightly jointed the saw, set the file holder angles by eye for the first half of the saw, then reversed the angles for the other half. It went quickly.

I also used the filing handle on a fourth saw, a brand new one. That one isn’t finished yet; I’ll post when it is.

A summary regarding the Veritas file handle is as follows: I don’t think that the accuracy of the rake and fleam angle measurements are important. Consistency is more important, and it works fine for that, but not any better than a paper fleam guide and blocks of wood (and remember that practice trumps all). It also won’t help you with the most important part of saw filing: keeping the tooth height uniform (just use a jointer; if you want to throw even more money at them, Lee Valley can sell you one).

For me, it does what I want it to do. There are no more blocks of wood cluttering my saw sharpening supplies, and it’s fairly comfortable to grip. The extra force that I can apply to the file stroke when shaping new teeth is a welcome bonus.

Cutting New Saw Teeth

When I remark that I’ve cut teeth entirely from scratch on many of my saws, some people think that it either involves stamping, a machine, or some sort of magic trick. It’s nothing of the sort. If a klutz like me can do it on the abomination of a saw vise that I have, anyone can.

It’s actually quite simple because it’s derived from normal saw-sharpening practice. You start with a file with a handle and flat block of wood as described in Lee’s book and any saw sharpening site out there. To get the tooth spacing, make yourself a little guide. I wrote my own PostScript program to do it (check the Plans and Guides page for PDF versions), but I imagine that there are plenty of ways you can do it with several packages.

Get some reading glasses; they help a lot.

Fold the guide over the front jaw of the vise, put the blade in, just peeking over the top, and make a first pass with the file, just filing in a little notch over the top of each line (sorry about the fuzziness, but I just don’t have a macro lens):

Notice that I’m not really getting the spacing spot-on; you can tell from the flats at the tips of the newly-formed teeth. Don’t worry about this on your first pass–you’re going to refine it later on. You don’t even have to worry much about the file itself on the first pass. The one I’m using here is way too big for the final tooth size (this will be a 16TPI saw that I will reveal later). I’m doing this because I don’t want to put unnecessary wear on a relatively expensive small saw file.

After you’re done with the first pass, do a second pass to go deeper. Make an attempt to correct for uneven spacing by putting a little pressure left or right as you’re filing, but use a very light touch; don’t make any extra strokes with the file just to even it out, and don’t press harder than you normally would. You still want to be fairly consistent in the newly-cut tooth valley size. The unevenness will disappear as you make more passes with the file.

In the saw above, the teeth are so small that I went most of the way with my second pass, this time using a file that’s appropriate for the pitch. You can see that the teeth are slightly uneven, but not by extreme amounts:

I then set the teeth, jointed them, and did a final filing. At that point, the teeth were quite even. It’s important to joint and file after you set the teeth because the act of setting the teeth dramatically alters the orientation and shape of the cutting edges. In addition, you’ll often accidentally set the teeth more than you need. A final pass at sharpening helps reduce the set. For the saw above, I used a fine-tooth saw set at its minimal setting, and it was still too much!

Rip Panel Saw: Choosing a Sawplate

While the handle is in the varnishing stage, I’ve been worrying about how to approach the sawplate for the new saw. Being the cheapskate that I am, I have been considering using the plate from this thing that I picked up for a song and a dance some time ago:

The basic shape is right, but of course, I’d cut the tip off to make it look halfway normal, mill off the teeth, and cut new ones, and do whatever else is necessary to get it fit on the handle.

The trick to all of this is the thickness of the plate. It’s kind of a tricky business, because all of the old saws were taper-ground, and you won’t find a cheap saw these days that is. So I’d be giving that up, but I don’t have any old saws that I can cannibalize anyway.

Furthermore, until now, I really didn’t know the thicknesses of any of the plates that I was working with; I was only able to sort of guess by looking at them. Well, that all changed when I finally got off my butt and bought a micrometer. Why I didn’t get one before, I’ll never know. It’s really taken a lot of the guesswork out of a lot of stuff.

I’d been wondering about this because I’ve got saws that turned out in certain unexpected ways due to this, and I really didn’t know about it before. For example, my crosscut carcase saw works wonderfully, but a rip version of it didn’t turn out the way I wanted it to. The plate on those two saws is .0263″, but you’d really want something more like the 0.020″ thickness found on most dovetail saws.

What’s .0063″ of difference? Well, one way to think about it is that it’s 31.5% thicker, which is pretty significant. In theory, you’re cutting 31.5% more wood, and so it’s 31.5% more work to do it. (This does not hold for a crosscut saw, where you are slicing fibers out instead of scooping shavings.) You can also look at it visually; take a look at the following image that I just cobbled together as a PostScript program:

The difference between .020 and .0263 looks pretty striking here. These thicknesses are at the cutting edge. I have the measurements for the tops of the saws that are taper ground, but I’m going to set that aside for the moment.

As you might have noticed, I put labels on this image. Of course, after I got my micrometer, I obsessively measured all of my saws. I don’t have a Kenyon saw, but it’s listed here as a representative for a big tenon saw (the Wenzloff versions have .025″ plates).

There are some surprises, such as that Stanley dovetail saw with the gents handle. This is a relatively new one that I picked out of a basement. I never bothered with it because I already had the Crown equivalent (.0205″), but you can see that it’s quite thin! This is the saw featured in Korn’s book, and it should be pretty obvious that if you’re willing to learn how to sharpen it, it will give you experience with a thinner plate and should work just fine. It’s no wonder he has no trouble recommending it.

So getting back to the question at hand, is the lovely “Kobalt” plate going to work? I think I’m going to give it a shot. It’s about 16% thicker on its cutting edge than the original that I’m working with, but that doesn’t seem that bad (and some of this thickness may be lacquer). The thickness of the original is a little unusual anyway; full-size saws are about 33% thicker. The only blade I have that’s close is my frame saw blade (0.029″), and, er, that’s not gonna work.

Then there’s the matter of taper-grinding. Should I try this? I’ve got sort of an idea of how I can do it without a power tool (although if I were sane, I’d ask to use someone’s belt sander). Would that warp the plate? Hmm.

Frankensaw; Saw Sharpening Guides

I’m finally done with sharpening the last saw on my to-do list. This and the one in my previous post were both acquired at an estate sale over in the Sunset district last year. They’re both Disston No. 7s, but both have been rehandled. The first one I worked on had some sort of modernish handle on it. The one I just finished has a No. 12 handle.

Someone must have liked these saws. They were both rust-free and had pretty good visible etches. Unfortunately, the sharpening on them was crap. The No. 7/12 Frankensaw needed serious jointing (and therefore, serious tooth reshaping) before it could be pointed.

But once at the pointing stage, things went pretty quickly in spite of it being a 26″ saw with 8 teeth per inch. I used a 10 degree fleam angle this time, and used a roughly 10 degree slope on the gullets as well. Here’s a shot of the sharpening in progress:

This picture shows one of the issues that often comes up when sharpening crosscut saws that I’ve been talking about recently, and that is, that the shape that the tooth appears to be can be misleading. Look at the teeth on the right side of the saw in the preceding image. See how they look kind of spindly? It’s a trick of the reflected light. Here’s a close-up, where you can see the reflections and the full tooth profile:

Obviously, there are some uneven spots here, too, like the second-to-left gullet, but those were taken care of on a second pass. but the point is that you have to be careful about what you see. Just be consistent with the angles you work at, look at the tops of the teeth to see when you’re done.

Here is the saw in its finished state:

You can see my fleam guide in the photo of the work in progress. I worked a little on the code for this before starting this saw. My previous version required you to use two different cutouts to sharpen each side of the teeth. That was kind of stupid, because you can see only one side of it at a time. So I reworked it.

Update: I now recommend that you use the versions that are on the Plans and Guides page rather than the following, but I’m not going to remove these any time soon.

Here are PDF versions for:

If you know how to use PostScript, ask me for the source code; you can put in any fleam angle you like. (I haven’t figured out how to trick WordPress into letting me upload a .ps file without doing something stupid like archiving yet, sigh.)

Also, I have a PDF tooth pitch gauge (toothgauge) that you might be able to use at some point.

My Sloped Gullets

Leif over at Norse Woodsmith did a recent post on sloped gullets. Strangely enough, I’ve been working on restoring a couple of saws lately, and about the time he posted, I was starting to sharpen one of them, an old Disston No. 7. I finished this morning and decided to take a photo of the result. Unfortunately, I don’t have a macro lens, so I can’t get much better than the following shot, and also unfortunately, I don’t think the angle is very good, because you can’t really see the bottom of the gullets too well:

In any case, take a look at the bottom of the brightly reflected edges, and you’ll see that the rear is higher than the front, especially on that tooth all the way to the left. This shot was taken straight from the saw coming off the file, so you can see some burr here and there. You can also see how difficult it is to judge the height and shape of the teeth here. In this shot, it looks like the teeth set towards the camera (the all-dark ones) are a little bit lower than the ones set away, but in reality, they’re all the same. It really is easier to tell by jointing the teeth and filing until the flats are gone.

I’d mentioned in a comment on Leif’s post that the angle I used for fleam and slope was not that great. On further inspection, it seems to be moderate. The fleam angle is 20 degrees and the slope is about the same. I think a 10-15 degree fleam and slope would be easier to file, and I plan to try it out on the other saw I need to sharpen.

All of this theory is useless if it doesn’t work in practice. Here is a test cut in beech:

It’s about what you would expect from a 6TPI saw that’s 26″ long. The important part is that it belches sawdust profusely when sawing, and with a controlled cut, you don’t get much tearout. And it’s always nice to get a 110+ year old tool working again.

Frame Saw: Important tweaks

After a bunch of sessions with the new frame saw, I determined that it wasn’t working the way it was supposed to. It didn’t cut quickly, the kerf was too wide, and the blade wandered all over the place. I suspected that more than one thing was wrong, and I had a few ideas.

First, I caught on to the fact that the blade wasn’t really sharp, although it had the appearance of being sharp. I really need to learn that if the guy who made your saw doesn’t have a name like Wenzloff, it probably isn’t sharp, so you should save yourself a lot of trouble and sharpen it before using it. Groan.

I reshaped the teeth to have a fairly aggressive zero-degree rake angle, and took a considerable amount of care when sharpening to make sure that the tips were all very close to the same height. The result looks like this:

frame_saw_new_teeth

When doing this, I realized two additional things about this blade. First, it had way too much set, and second, the saw plate is a little thicker than I thought it was. This latter point was a big deal, because it seemed like the tips of the points originally were chamfered or slightly rounded. I couldn’t see this originally, even with reading glasses. And obviously, it makes a big difference in use, because, as I find over and over again, sofa-shaped blades don’t cut wood very well. (I wonder why.)

The difference in sharpening alone was really remarkable. Because the process removed most of the set, it made for a wonderfully thin kerf, and therefore, it tracked a line much better, even though the blade wasn’t terribly taut. And the more aggressive and sharp teeth cut much faster and smoother.

Now, the second problem I was having was that I couldn’t increase the blade tension too much, because the little screws that I was using to hold the blade in place were snapping due to the tension:

frame_saw_failed_pins

Yikes. So I cut and filed a few brads for this purpose:

frame_saw_new_pins

Now that there’s enough tension, I don’t have a problem with the blade twisting around (thanks for the pointer, Dan). The only issue I have now is that it’s difficult to keep the blade straight when tightening it up. Christopher Swingley uses a wrench on the flats, which seems like an idea that might work.

After making these two changes, this saw really seems to be on the right track, and I think I’ll be able to do decent work with it. I already sawed out some 3/16″ slices from a couple of smaller boards (without even marking!), and they came out great.

There always seems to be a lot of discussion about frame saws, and what kind of blade is appropriate. Tom Holloway’s saws use thin blades, and I can attest to how effective they are, having played with them. Bob Easton uses thicker blades from old Disston saws and that seems to work too. It seems to me that there’s more than one way to skin a cat.

A case in point here is what I edited in as a note in my last post, that there’s a version of a Japanese saw, the “oga kobiki” or something, that has a gigantic blade, but seems remarkably easy to use. Check out the pictures in this link if you haven’t yet. You see how that tiny woman is using that huge saw? Look at how beautifully the cut turns out. Oh, how I would love to examine that saw that they’re using.

So it seems that if the kerf is even enough–not too wide, not too narrow, of constant width, and straight–it doesn’t matter how big your blade is, as long as it’s slippery and sharp.

I don’t think this is going to be the last blade for this frame saw. I’ve got some ideas that might make it faster. Let’s just say that the gigantic teeth on the Japanese saw got me thinking.

I also got to thinking that I might need to do something about my saw vise. It works pretty well for small saws, but when you start to file the big teeth, it shakes too much. What to do here? Finally make my own? Cave in and get one of those new Gramercy saw vises? Find someone who has a good one and mug them?

A D-8 named Sawthra

The last saw to be complete from the pile o’ handles I refinished a while back was a 28″ Disston D-8. The plan was to make it a replacement for the 7 TPI D-7 that I’d been using for a rip saw.

When I first got the D-8, I was somewhat ecstatic. The blade was pretty clean, reasonably straight, and even had its etch. So all I needed to do was refinish the handle, clean off the blade, and sharpen. Easy, right?

Well, I got to sharpening, and about halfway through from the heel to toe, my file started to make strange noises and didn’t want to cut the metal. Huh. It turns out that there was a roughly 8-inch length where someone had done something unholy to the teeth. They were hard, very hard. We’re talking “breaks the teeth off your file” hard here.

I wasn’t going to let a saw make a monkey out of me, though, and managed to work through the hard metal. It seemed to go about 1/8″ deep into the blade. After this, I was tired. Very tired. I thought, well, maybe I should name this thing “Sawzilla,” but quick research indicated that it wasn’t a terribly original name. So here is Sawthra, named after the slightly more obscure Mothra:

disston_d8_sawthra

The Disston D-8 brings me to another thought I’d been having lately, namely, “wouldn’t it be great to have a brand-new D-8?” Then at Bagathon, I made a rather unusual deal with Larry that brought me this saw:

pax_no1

Notice anything familiar about this 24-inch Pax “No 1″ panel saw? Like, maybe, that it’s a total copy of the Disston D-8, even down to the handle and the screw arrangement?

So I really do have a practically brand-new D-8 now. It makes sense, I suppose. The Flinn company tends to catch a lot of flak about its saws, in particular, that the handles aren’t as nice as century-old handles. But they do at least reproduce a true classic handsaw. The blade is taper-ground, for whatever that’s worth. Although I wouldn’t characterize the teeth on this thing as “sharp” (my little carcase saw currently cuts faster than this thing at the moment), they don’t look too bad, and probably need a little touch-up. I’ll wax the blade, like I always do.

The handle? Well, I’m not sure if I want to make a new one or not. To be honest, the handle isn’t that bad. But I always seem to end up making handles.

A Tale of Two Saws

Or, rather, two descriptions. I finally finished the pile o’ handles I was working on, and two of the saws on which they belong are complete:

The one in the back is a 28″ Disston No. 7. When I got it, it was filed at 4.5TPI crosscut. However, this pitch (and the saw’s handle) is far more suited for ripping, so during sharpening, I converted it to a rip saw. For the first time when simply modifying teeth on an old saw, I needed to add some set–there was practically none. Although the surface looks a little funky (strange corrosion patterns), it’s actually pretty smooth, and it tears through wood like a bat out of hell. I have wanted this saw to be complete for a long time. I’ll be using it a lot.

The other saw is a “Warranted Superior” backsaw from the 50s or so. There’s nothing remarkable about it. It’s not mine (it belongs to someone in the family), but I’ve had it for a while because it was in bad need of a rehab. The teeth had been nearly worn off in places. Nasty. So, after refinishing the handle and redoing the teeth, it cuts about as well as you’d hope it to. Interestingly, it’s been a while since I did crosscut filing; most of my latest projects have revolved around different varieties of rip saws.

Unfortunately, this thing was on my project list for a couple of years. Now I can finally send it back to its owner.

Winchester Saw: Finished

My Winchester No. 16 handsaw has been sitting around waiting for me to do something to it since time began. I’ve had this saw for nearly five years. When I finally decided to do something about it, it was back in March, when I discovered that it was a Winchester:

 

I didn’t know what to do with it at that point. It’s a mildly rare saw, so one option was to try to sell it for something useful, for example, a pile of Disston D-8s. But the handle was in crap condition, and it had the less-snazzy “Warranted Superior” medallion, so I decided to restore it and keep it as a user. I don’t know when I decided to do that, but it was a long time ago, and as such, I’ve had the blade sitting around, derusted and waxed, waiting for sharpening. I took the handle off, and procrastinated on the refinishing.

About three weeks ago, I decided to do something about it. I finished today:

 

The saw was filed to 6TPI. That’s pretty coarse for a crosscut saw, so I was originally going to make this a ripsaw to replace my beat-up D-7. However, the handle has that funny notch on the top that would make ripping uncomfortable with two hands, so I figured decided that this would, in fact, remain a crosscut saw. The rake angle is 15 degrees, with the fleam angle at 20 degrees. I had initially filed a 20-degree rake angle, but I screwed up pointing it (of course), so on my second try, I decided that since it was so coarse that I should make it a little more aggressive. It was probably a good idea; it does saw very efficiently. The cut is fairly clean for 6TPI.

I spent about a million years refinishing the handle. It was dented, nicked, and beat up. This photo also shows how the top horn was mangled:

 

The first thing I did (several months ago) was strip the original finish. At the same time, I cleaned the sawnuts:

 

And then it sat. And sat. And sat, until about three weeks ago. Even after stripping the original finish, it was still really uneven, so I sanded around the curved parts. For the flat parts, I just skimmed it with a smoothing plane. At this time, I also learned what the wood in the handle was for the first time–American Beech (fagus grandfolia). OK, well, that’s not a big surprise.

Then there were decisions. Should I stain it? With what? I finally settled on few thin coats of a “Colonial Maple” pigment stain. I used a washcoat beforehand. Though it would result in accented nicks and dents, it would even out the flat parts, and who’s going to try to hide the fact that this saw hasn’t been used, anyway?

Finally, I decided to use the same flat-sheen polyurethane that I used on the mallet as a protective top layer. I went from a thin coat to thicker coats, then back down to thin coats for the final one. Several coats were necessary, because the varnish would run down the surfaces that were vertical, depending on the way you held the handle. I did the first coats with the handle held upright, then the later ones held flat. A close-up of the finished handle:

 

I used a progression of 320 grit sandpaper, #0000 steel wool, 1500 grit sandpaper, and rottenstone, all lubricated with mineral oil, to rub out the finish. There’s still a scratch here and there from the coarse-grit paper (because polyurethane is tough), but overall, it looks nice, and it’s very smooth to the touch.

Small tenon saw, Part 2

So the old ridiculous teeth were all filed off, and it was time to put on new teeth. On Thursday, I decided on 14 TPI (teeth per inch), put the saw along with a tooth guide in the saw vise, and set out to rock and roll.

It was not as easy to get the new teeth started as I would have hoped. I tried a small hacksaw at first. That didn’t work out, so I moved to a handsaw file. That wasn’t fine enough, so I finally dug out a set of hobbyist-grade needle files and found one that had sort of a knife-like edge. That worked, but it was slow, because that file sucked. It took forever to get the 140 little notches cut for the teeth, and my hand felt a little funky after doing it, but it was precise, so I was happy, and left it for a while.

On Sunday, I picked a rake angle of 20 degrees, and went to town shaping the teeth. Here’s what it looked like halfway through:

And close up…

After setting the teeth and a jointing, it was time to point the teeth. I chose 20 degrees for the fleam as well.

The result was far better than any crosscut sharpening I’d done before. (I don’t have a closeup, maybe on the next installment.) The best part, though, is the way the saw cuts–smoothly and quickly.

So now I have a workable small tenon saw. I don’t like the gent’s handle, and I do want to replace it with a closed-grip handle, but this is not an immediate need; I want to practice making tenons with it before going into further modifications. I’ll make the handle later.

I’m so happy with the way this has turned out that I’m considering buying a second saw for use as a ripsaw. It would only set me back another $10. Whee…