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Eric Schubert
08-21-2014, 3:55 PM
I've been reading a lot of information regarding saw sharpening lately, and something struck me as odd. (Keep in mind that I'm both new to woodworking and I've yet to attempt sharpening a saw, so all I have is information and no experience.)

If I follow what seems to be the accepted steps of saw sharpening (joint, file/shape teeth, set, file fleam, dress with oil stone), I see that you shape the teeth before setting them. Rip saws are usually shown having tips that cut flat, while crosscut saws will cut along the tips, causing a small peak in the center of the cut due to fleam.

If I set the teeth after shaping them, the tips will not be flat. They'll be bent slightly outward, cutting a slight groove down the center of the curf. The tips would not really be flat.

Would it make sense to joint the saw again after setting the teeth to get a flat tip? Or is this just being overly picky about details that don't really matter? Do the tips flatten out as you file the fleam? (I don't see how they could, but maybe I'm missing something.)

David Weaver
08-21-2014, 3:59 PM
It really doesn't make any difference if you set a saw last or next to last or third from last.

The reason for the rows on a crosscut saw is only due to the fleam and not due to anything else. They'll be there even if you set the saw as a last step (which is what I do, and I've never had trouble getting any saws to do what they're supposed to do - nor would I have trouble if I set earlier).

if you think about it, you'll refresh a saw a couple of times without setting the teeth again - at least laziness will drive you to that (and pragmatism), setting only when it's needed. That's more like setting next to last, even if you set and stone last when you do set.

When you sharpen a few saws and you get a couple that come up short in terms of speed and bite, it will become immediately evident which things matter (teeth relatively similar height with no flats on them) and which aren't (identically sized teeth, identical fleam tooth to tooth, when you set the teeth, etc).

Tom M King
08-21-2014, 4:24 PM
That's the reason I've always set the teeth on a rip saw first, but I don't really know that it makes much difference. Sometimes it is better to have the outside edges a wee bit higher. I'm not sure about the effect of having the center of the teeth higher.

I'll whet a saw two or three times, and only set it when it needs it otherwise. For some woods, I'll put a little angle on the vise for a rip saw to make the edges of the kerf cleaner (smallish V sort of like a crosscutter).

I only stone one if it has a tooth or three to hit outside the others somewhere in the cut. Then I just hit that spot. I dont' know that I have ever done a whole side of one.

Jim Matthews
08-21-2014, 5:06 PM
I apply set last. If I needed to reshape the teeth, I would set before filing.
I don't bother with saws that are that far gone - that's for Big Dogs like Mike Allen.

For me, setting before filing means that I could be filing off some of the set and
inducing bias in the cut as a result. If I set last, I know that it's consistent.

I file everything with teeth smaller than 10 TPI progressive ripcut.

I don't get the finest results, I'm sure - but they're consistent and simple.

http://norsewoodsmith.com/content/sharpening-continued

Eric Schubert
08-21-2014, 5:59 PM
Thanks, guys.

I didn't know if having flat bottoms for a rip saw made any difference when cutting wood. And actually now that I think about it, having a slight groove down the center from setting teeth after shaping/sharpening may help the saw track better. The order makes even less of a difference for crosscut saws with fleam.

Being a mechanical engineer makes me consider some of the minute details. It may make for an interesting conversation about theory, but perhaps it doesn't make any difference in reality. To compare results in the real world of jointing teeth on a rip saw a second time after shaping and setting them to truly get flat-tipped teeth would likely only be to satisfy my own curiosity.

David Weaver
08-21-2014, 6:21 PM
We've all been the minute details. The ability to consider them is what is going to allow you to do better work later on. It's nice, however, when experience Allows you to disregard some of the details as immaterial.

Jim Koepke
08-22-2014, 11:56 AM
With an old saw there is often too much set from a previous owner.

If one is building a new saw it is often that the new saw plate is used without set to cut the kerf in the handle.

Other than that, it really doesn't matter.

jtk

Fitzhugh Freeman
08-22-2014, 4:02 PM
I've just taken the plunge myself, though I did sharpen a few a while back, choosing the ones with which i could just let the file follow what was there.
As a novice I do have a piece of advise I ignored for too long myself: go ahead and try. I had tried to get it all sorted in my head first but now I've found a little time with a file on a saw and the book knowledge all seems to be clicking into place. I first did a craftsman plywood handled saw a neighbor was tossing, a good choice because I was more worried about wasting the file than the saw. It cuts nicely now. What an eye opener.