Let’s make a saw….Finale (Part 4)

After much anticipation, the time has finally come to sharpen this little lady up and get her out on the dance floor once more…I think she’ll be a real delight! ;o)

Sharpening a hand saw is without a doubt a topic about which you will find much literature, both in print and online (relatively speaking of course….It’s not quite as popular a google search as Lindsey Lohan…well, not yet anyway!) Everyone has their own way of doing it (sharpening that is, not Lindsey Lohan) and I am no different…but all of us do share certain steps in common.

However, in stead of launching into a long post, I will briefly cover how i sharpen. I certainly will be posting an in depth tutorial on my sharpening and filing methods in the future, so look for that soon.

To start, of course, I select the appropriate triangular tapered file for the teeth, and my trusty mill file  for jointing. You can use a chart to match the pitch of the saw to the file (see below, curteousy of Tools For Working Wood) or you can match a file on hand to the height of the saw tooth (the saw tooth should be half the height of the width of the file face) Some use a smaller file than this…Mike Wenzloff asserts that you should use the smallest file that will work in order to give the deepest gullet. I have done both and not noticed a big difference…plus, I’m cheap so I use the traditional method to get three usable sides to every file.

For this saw, since its 8 points, I use a 7 inch extra slim taper file, and of course, a handle…I like the Skroo-Zon brand the best…comfy and they grip tight.  You can get good files and supplies here or here.

Here are the files I will use…you will note the mill file mounted into a block of wood to keep it square to the tooth line…

The first step is of course jointing. I run the mill file across the tops of the teeth to level them…a few passes and each tooth should show a tiny flat area on the top. The jointing is essential and ensures that each tooth be the exact same height and do its duty as required of a fine saw. I’m sure you’ve seen many old saws with tooth lines that look like a roller coaster track…these saws do NOT perform at their peak and are the result of not jointing teeth before sharpening.

Here she is mounted in my old Disston #2 saw vice after jointing…you can just see the tiny flats on the tip of each tooth from jointing…

The teeth on this old saw plate (now our NEW saw plate actually) are in decent shape…very straight and level so only a few strokes of the mill file and their all level. This saw was originally a cross cut saw, so the teeth have a good amount of fleam on them. Fleam is created by changing the file angle relative to the tooth line to create a more acute angle on the edge of the tooth, thusly making a knife point (you can see this in the illustration above). This edge, as opposed to a chisel like edge for rip teeth, more efficiently and cleanly severs the cross grain fibers of wood. Without launching into an extensive treatise on saw tooth geometry, those links above for saw files will also lead you to the websites of Joel Moskowitz and Pete Tarran, respectively, both of which contain great info on saw teeth geometry and function, as well as on sharpening.

So now I’m ready to file the teeth, but interestingly enough, I’m not going to keep any fleam on this saw. Why? Because lately I have been putting a theory of some to the test….namely, that fleam in not necessary on hand saws. Yes….I said NOT NECESSARY. So, this saw is going to be one of my “fleam free” experiemental saws. I’ll put her through her paces in both ripping and cross cutting and report back how she does.

As a note, interestingly enough, the greatest advocate of fleam free saws was Tage Frid….also a Rhode Islander like myself. Perhaps I feel some inclination to test his theory out of a geographic loyalty? Or state pride? Perhaps. Or perhaps, maybe i just like causing scandal in my tiny little cyberspace woodworking community. ;o)

Anyway, no fleam it is on this 8 point saw. I will use a somewhat relaxed rake though…I don’t measure…I just use a consistant angle to keep the theeth even. Also, this relaxed rake will help with cross cutting somewhat.

So now onto filing…it only takes a few strokes per tooth to get most of the fleam out. Here’s a pic…you can still see a bit of the bevels on the teeth….the last remnants of fleam…

Another light jointing, more filing and the teeth are just about finished.

Next, I always set my teeth and then sharpen…some sharpen first, then set, but to me, setting first makes sense because when the teeth are set, it changes the geometry of the tooth. If you set first, then joint lightly again and THEN sharpen last, you ensure that all the teeth are of even height and shape.

To set, I use my trusty Somax saw set on the #10 setting…

Now for another light jointing just to top the teeth and keep them even…and then the actual sharpening.

I sharpen my saws filing all teeth from the same side…I don’t flip the saw around in the vise for the alternately set teeth and here’s why: Good sharpening is about creating muscle memory and keeping consistent filing angles. When you turn the file around in the vise to file the alternate teeth, you create a whole new angle to hold your file at…and a whole new set of potential errors. By filing from one side, you only have to worry about the one rake angle of the teeth and keep it. Like I said, its about developing muscle memory in your wrists…why work so hard at creating that muscle memory if you’re going to turn the saw around and erase it? Interestingly enough, I think I just read on Andrew Lunn’s blog that he does the same thing. Smart guy! FWIW, I’ve never noticed any adverse effects from only having burrs on one side, as I stone them off anyway…

So after the final sharpening, I remove the saw from the vise and stone the sides of the teeth…this evens the set and removes the burrs noted above. Two swipes per side and she’s done!!!!

Now we can put this baby to wood! I have some birch ply next to my bench, so I fix it up and rip away….she tracks good out of the gate….take a look…

Not too shabby! Since I filed this saw as kind of a hybrid (8 points, relaxed rake, no fleam) I’m going to give it a good work out cross cutting 4/4 through 10/4 stock, some plywood work, and light ripping in thinner stock and see where she shines. It will be interesting to find out. I’ve been using more fleam-free saws in my shop, though this is the corsest pitch thus far…I’ll report back soon on how they do.

Here’s some more shots of our new saw….

I hope you enjoyed this project as much as I did…thanks for stoppin’ by.

And as always, more to come soon…!

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Published in: on November 3, 2010 at 1:06 pm  Comments (8)  

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8 CommentsLeave a comment

  1. No fleam eh? Watch out for flaming bags of dog poo on your front porch with a statement like that. Ok I’m game, can you explain the basis for your theory a bit? I have certainly heard the opposite that a crosscut saw can rip but not the other way around because the relaxed rake and fleam make for a cleaner slicing cut. Are you suggesting that only the rake is what accounts for this slicing? It is possible that like all things in our information overload digital age that we are just over analyzing the saw tooth geometry issue and as long as the saw is sharp it will cut well. I’ll be watching to see how your experiment works out. It would certainly make sharpening easier to ditch the fleam.

    • Thanks for the comment Shannon…good questions….

      Flaming bags of dog poop though, huh? Sweet! ;o)

      As for the basis of my theory, well its not really my theory at all…Chris Schwartz had written a bit on the origins of fleam, as have others. The thinking right now (IIRC) is that fleam probably showed up sometime on western saws in the 17th or 18th century…no one is certain for sure, but there does seen to be agreement among tool historians that fleam is a recent addition in the 5000 or so year history of saws (three hundred years in 5000 is relatively recent)

      I’m most certainly not an a tool expert, or historian, but my thinking is that, just as you say, cross grain cutting can be accomplished with a relaxed rake that acts more like a shear than a chisel. My big question at this point is how well will the edge hold up as a shear? Teeth being filed straight across and having a working edge of 90 degrees certainly makes it more stout than a more acute angle with fleam (85 to 45 degrees at the extreme)so this may help.

      So far, I’ve experimented with high pitch saws with no fleam…I have a couple panel saws with 10, 11 and 12 points (a tenon saw too) with relaxed rake and no fleam. They cut fast and leave an acceptable finish on cross grain cuts, but I need to use them more and see how the teeth hold up.

      As I mentioned, Tage Frid wrote and stated often that the first thing he would do upon getting a new saw was to file the fleam out of it. He claimed it made the saw faster and plenty smooth…testimony enough for me to try it at least…so, you can call it HIS theory that I’m testing out.

      Matt

  2. “I just use a consistant angle to keep the theeth even. Also,….”

    Hi Matt. That would be “consistent” and “teeth”. From your friendly editor.

    I guess since the world was only know to be round since the 1400’s then it is relatively recent, and maybe it really is flat? Just sayin’.

    I would like to see you take a crosscut Acme 120 and file it rip. I think I could hear the screeching from here.

    Also there is something about an argument that contains a statement saying relaxing the rake will make it more like a crosscut saw.

    I would argue that it is much harder to file a saw crosscut and get it consistently correct, and if it doesn’t give you any advantage why do it?

    Rick

    • @Rick: common misconception, but utterly untrue. Eratosthenes proved the world was round as early as the late 3rd century BC. From your friendly fact-checker.

      And by the way, that would be, “the world was only knowN to be round…”
      Just sayin’…

      Thanks for the fun and passionate content on this new blog, Matt. Keep it up.

  3. I can hear that screaching from here too, Rick…don’t think that’s one I’d put to the “fleam-free” test.

  4. A nice series. I have a Disston 12 that belonged to my father. It is a favorite. Your finished product looks almost like it, so well done.

  5. Thanks for the blogging. I am working to try to improve my saw sharpening, so I am eager to hear more about your technique. I do have a couple of quick questions. First, you sharpen filing all the same way. If you were to use fleam, would you still do this, with the angle changing every other tooth? Also, have you ever had problems with what Tom Law calls “little tooth, big tooth,” or something like that? I read about it on the Tom Law blurb you can download from the Tools for Working Wood Web site, and still I am having this problem with my saws.

    Thanks!

    • Thanks for the questions Matt and I’m glad to hear you are enjoying the blog.

      I should clarify one thing, as several people have asked about it….I do use fleam on some of my saws. I’m not swearing it off, I’m just making a few fleam free saws to try them out and see how they work. Call me crazy, but when I learned about Frid’s theory, I just had to try it out.

      When I do file a saw with fleam, I use both sharpening methods…all from the same side, and flipping the saw around to alternate sides. the reason I do both, is because I like to try new things and find what works best. Plus, when I first started sharpening saws, I had trouble maintaining the proper rake angle when I would flip the saw around, so filing all from one side made sense, especially for rip saws.

      That said, filing all from one side on a saw with fleam can be a little screechy….especially on low pitch saws (less than 7 or 8 points), so those might be best sharpened from both sides.

      If you haven’t noticed, I like to always try new things. I’ll sharpen one way for a while, then try a different approach…it keeps me learning and trying new things. I encourage you to do the same. there are no hard and fast rules!!!

      Challenge convention, question assumptions, try new things and make your mind up for yourself…at least that how I roll! ;o)

      And the ‘little tooth, big tooth’ challenge is always tough to over come…maybe even the MOST difficult when you are first learning to sharpen. I found that the best way to remedy this is to know your file, and learn how to read the teeth. By knowing how and where to accentuate your stroke, you can choose where to remove material on a tooth. Then, when you learn how to read a tooth and where more or less material needs to be filed away, you can remove more from the big tooth and less from the little tooth easily.

      I will certainly be posting more about the specifics of filing and sharpening in the future…and this concern in particular. Stay tuned and keep practicing!
      -Matt


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