Saw Jointing Question

Re: Saw Jointing Question

Dean J in MN

>

It appears that the blade has a gentle curve in it - with both ends of the saw on a straight edge, the middle of the blade is a bit above the straight edge.

Should I leave it as is and just sharpen it? I suspect not. My impulse is to scribe a line and file the blade down on one end or the other. Is that a good idea? If I did that it would take the blade down about 1/8" at either the heel or toe. All things being equal, is one end better than the other? My impulse is to take it off the heel.

I'm a bit confused -- Is the blade (tooth edge) convex or concave? Sounds like it is convex, that is fine. But the last paragraph makes it sound like the toe and heel are higher? (The taking the blade down 1/8" in toe/heel comment threw me).

If it is convex (breasted), you can work with it as is, some people like breasted saws.

-Dean

Re: Saw Jointing Question

Skip in Falls Church

>Hi Dean,

Sorry, I was trying to be *so* careful in my description - it's the opposite of breasted (I *think*), concave. With the heel and toe on a flat surface, the center portion of the blade is not in contact with the surface.

Skip - Still wondering if this saw sharpening is such a good idea. :)

Re: Saw Jointing Question

Mark Kuzee

>Skip,

I've sharpened a number of saws with the same malady you describe. I assume that people sharpened the part of the saw that was dull (basically the middle 80/90% of the blade). After a few sharpenings the tooth line began to receed some. I say you should sharpen to at least a straight line and over time have a slight concave (breasted) shape.

Here's what I do:

Take a straight piece of hardwood (or some other sacrificial straigtedge) and clamp this to the saw so that the bottom of the end gullets are just below the straightedge. Clamp the saw and all together and file down all the exposed teeth until your file contacts the straightedge. Keep your file 90 degrees from the blade during this time just like you were jointing the saw. All gullet bases should still be visual for you to start sharpening at this point. Remove your straightedge and sharpen only the teeth you need. Repeat as needed till you can joint the saw conventionally.

I use liquid shoe polish to make the teeth more visible. Slop some on and wait a minute and joint the saw and the flats will really pop.

Heck you need the practice anyway. I find that it isn't hard to improve on most old saws as far as the sharpening goes. But to get one "dead nuts" on the money takes some practice.

Let me know if you need more help.

Mark

Re: Saw Jointing Question

Dean J in MN

>Ahhh... Yeah, I'd joint it flat, or breasted if you'd like. But, this may require cutting new teeth if you joint off too much.

However, you could look at this as great pratice in learning how to sharpen! If you joint a bit, then shape the teeth, then joint a little, then shape, etc, you'll end up with flat saw, you'll be comfortable with the shaping/filing of teeth and you're ready to tackle the next saw that comes along.

Dean

Re: Saw Jointing Question

Skip in Falls Church

>HI Dean,

Thanks, I suspected that was the answer. If I understand the method Mark described below, I can minimize the number of new teeth I have to cut by essentially taking metal off both ends. mumble, mumble

Skip

Re: Saw Jointing Question

Skip in Falls Church

>Hi Mark.

If I understand your method right (hoping I do)it's essentially a matter of taking a little off both ends preserving the gullets as a guide. That makes a lot of sense!

Skip

Re: Saw Jointing Question

Adam Cherubini, NJ

>Boy, I'm full of something today. Let's call it "opinions" since we're in mixed company (some power tool guys might be reading).

I've had bad experiences doing what Mark suggested. I can't explain exactly why, but what seems to happen to me is that I've got some teeth that look okay and some teeth that are just gullets. As I sharpen, the pitch gets all screwed up and I wind up with teeth all different sizes and shapes.

I'm not saying it can't be done. Obviously, this is what Mark does. But here's my alternative suggestion anyway:

Scribe a dead straight line, removing as little toe material as practical, then grind to the line with a bench grinder. Straighten and square that edge by jointing/draw filing then cut all new teeth. To get them all the same, count strokes (and start at the heel- by the time you get to the teeth you actually use, you'll have the process down pat). You get no more than one hour for the entire job. If you find its taking you all afternoon, write and ask for help. I'm so pleased and encouraged to say there are many fine sawyers and saw sharpeners here. That probably wasn't true 5 years ago. I think we all owe Pete Taran and Ralph Brendler (and several others) our gratitude for their trail blazing.

A 16" rip (is that what you said?) in my opinion, isn't all that helpful. If it was a backsaw, I'd feel differently. But a 16" cross cut saw can be a handy little tool. So I'd recommend 10-12 tpi, 20-30 degree rake 20-30 degree fleam tooth for this saw. I have a saw at pennsbury about like this with a straight handle on it like a bread knife. We like it. I was using it to saw tenon shoulders this past weekend in very poor light. Worked like a charm.

So that's my opinion and enough for the day!

Adam

Re: Saw Jointing Question

Skip in Falls Church

>Hmmm, a newbie to saw sharpening and two different opinions from two very experienced woodworkers I sense a dilemna coming on. It was so much easier when Tom Law was sharpening. :)

I realize it sounds a little funny to want a 16" rip saw - but I do a lot of smaller stuff, mostly boxes. (Have I mentioned that my wife is addicted to boxes?) I do have a 20" cross cut - and I guess I could use it but I'd rather use a rip saw on a rip cut. Using a 4 or 5 tpi rip on a piece of 3/8 or 1/4 inch stock a foot or so long just seemed a bit crude to me. :)

OTOH using a back saw on the same sized stock can be awkward. After struggling with back saws for so long it just seemed to me that a small rip saw was the solution. I was really hoping that Tom would have one at the PATINA in Damascus - but he didn't.

Skip (mumbling - a little off both ends, all of it off the heel?)

Can I change my answer?

Adam Cherubini

>See I knew I should have shut it. Ignore my post and stick with your instincts.

adam

Re: Can I change my answer?

Skip in Falls Church

>Hi Adam

No, I do thank you for the suggestions. You had no way of knowing exactly what I was doing and I didn't say. :) Besides, I owe you for freeing me of the tyrany of planing wood to some exact dimension in inches. It really does make things easier.

Skip

Re: Saw Jointing Question

paul womack

>Great answer!

In the light of Adam's comment, a little care should be taken to keep the teeth even sized - in practise this is same as keeping them evenly spaced.

Side -issue. It is normally recommended to file straight across (like a rip saw filing) when reshaping teeth, since it's both easier to do, and it saves having to "flip" the saw to file from each side.

BUT: if you're shaping teeth for a Xcut saw, I would recommend changing to a fleam angle a little early (as you move from shaping to sharpening). The initial change from straight across to "fleamed" filing can be quite disconcerting and hard to control. So I change early, to make the process slower, but easier.

BugBear