Help with sharpening handsaw

[lowell holmes]

I have been learning to sharpen handsaws. I have a saw vise and the files. Actually, I feel like I am making good progress. I have the Lee Valley sharpening jig.
I have successfully touched up both rip and crosscut saws.

After re-toothing a saw and setting the teeth, it will cut quickly and will saw on a line.
The issue that keeps cropping up is that the saw will hit a spot about 2/3 the length of the saw where it jams. I have to force it past that point.
I can do that by shear force or maybe easing the downward pressure on the saw.

I inspect the teeth, and they are not mishaped nor is the tooth set apparently wrong. I have re-jointed the saw and sharpened again, but the issue persists.
What am I overlooking?
Any help will be appreciated.

[Chris Griggs]

Check to make sure the tooth line is not subtly concave. I've redone saws that seemed perfectly jointed and filed only to have them jam up the way you describe. A straight edge revealed a subtle concave curvature across the toothline. Where the slope start going back up hill was precisely where it was jamming.

[David Weaver]

It could be high teeth or it could just be that the rake is too aggressive on the saws. If you put a straight edge on the teeth, or something relatively close to straight, do you see any high ones?

Is the rake consistent on the teeth?

If your rake is extremely aggressive on a rip saw, it will grab as you get to the end of a stroke.

[Jim Koepke]

The issue that keeps cropping up is that the saw will hit a spot about 2/3 the length of the saw where it jams. I have to force it past that point.

You do not mention whether this is a rip or cross cut saw.

Some of the causes for stopping in a cut have been mentioned. It could also be excessive set on one or more teeth.

Sometimes looking at the marks left by the saw in the cut pieces can indicate a problem of a few teeth being over set. It will have little gouges in the wood where the excess set is cutting a wider kerf.

Being very careful one can sometimes find the errant tooth/teeth by lightly running fingertips from heel to toe feeling for high or over set teeth.

Also knowing where the problem area lies a small ruler may help in identifying the misbehaving tooth/teeth.

Norsewoodsmith.com has information on > saw troubleshooting < that can be found by searching the site.

jtk

[Ken Shepard]

Before making any changes to the set, try rubbing the blade with a bit of candle wax. Sometimes with a taper ground blade, the set may not be quite enough to provide clearance for the thickest part of the blade, but with a bit of lubrication the saw will cut without binding.

[Mark Kuzee]

Lowell,
Without seeing the saw it would be hard to diagnose but I have a few things to check.

1. Is the blade clean. Get it clean and apply some wax.
2. Is the blade kinked. This can be a tough one to resolve.
3. You did not mention a brand or vintage of saw you are working with. If it is a lower quality saw I may respectfully suggest that you find a better quality to work with.
4. There is one other item that I would like to mention. I have found this on a few saws that I have sharpened and it really had me going for a while until I figured it out. If we knew what brand/age of saw you were working with we would know if it is a taper ground saw. A taper ground saw, when new, has a consistent thickness (gauge) at the tooth line. As the saw is sharpened (you mentioned retoothed) the tooth line can vary in gauge from thin at the toe to thicker under the handle. If you are using a minimum amount of set across the length you may be running into a situation where the kerf that is made by the toe is not able to accept the thickness of the blade 2/3 of the way. My clue was that you are having to force it past that point. If it was a kink you may be able to get past a kink but not if you have the scenario I described.
A quick test would be to determine the point at which the saw binds and add a little more set from that point to the toe.

Best of luck

Mark

[lowell holmes]

[QUOTE=Mark Kuzee;2137967]Lowell,
Without seeing the saw it would be hard to diagnose but I have a few things to check.

1. Is the blade clean. Get it clean and apply some wax.
2. Is the blade kinked. This can be a tough one to resolve.
3. You did not mention a brand or vintage of saw you are working with. If it is a lower quality saw I may respectfully suggest that you find a better quality to work with.
4. There is one other item that I would like to mention. I have found this on a few saws that I have sharpened and it really had me going for a while until I figured it out. If we knew what brand/age of saw you were working with we would know if it is a taper ground saw. A taper ground saw, when new, has a consistent thickness (gauge) at the tooth line. As the saw is sharpened (you mentioned retoothed) the tooth line can vary in gauge from thin at the toe to thicker under the handle. If you are using a minimum amount of set across the length you may be running into a situation where the kerf that is made by the toe is not able to accept the thickness of the blade 2/3 of the way. My clue was that you are having to force it past that point. If it was a kink you may be able to get past a kink but not if you have the scenario I described.
A quick test would be to determine the point at which the saw binds and add a little more set from that point to the toe.

Thanks for responding.

The saw is clean (not shiny), taper ground, Warranted Superior, 1960's vintage Craftsman. There are no obvious kinks. I converted it from cross cut to rip because I wanted a 10 point rip saw.
A few years ago, I had it sharpenedrip cut at Circle Saw (Houston). It cut straight, but was slow. I realised it had the original cross cut rake.

I severely jointed the saw almost smooth. I used a LV tool for filing card scrapers. I have a steel straight edge (LV) and I know the tooth line is straight, not bowed. I said I retoothed it, but really with
the severe jointing and re-shaping the teeth, filing to 8 degree rake, it amounted to retoothing. Initially, test cuts showed a fast cutting saw with no issues.

Then when I used the saw, the binding occurred. My next step is to flatten the set between two hardwood, endgrain blocks of wood, checking the teeth for any mis-shapen teeth.
I will set the teeth very carefully and go from there.

I took a piece of straight and square mdf and ran it down the side of the set. There are three or four teeth that are slightly protruding.

OBTW, I am using the LV file holder with Grobet files. I really like the file holder. It allows the rake adjustment to be made easily.

[Jim Matthews]

I have the same problem, with most all of my saws.

I suspect it's technique, where the front of the saw wants to tip downward,
and the angle of attack where the cutting edge of the teeth meets the wood
becomes progressively steep -

like uneven stair height, when you're carrying something heavy.

It's most pronounced, when I'm ripping a board that's vertical in my vise,
or pretty far along my sawbench - my arm wants to swing through a curve
and the sawteeth want to stay in the same plane.

As with most things, I find less force often more persuasive than trying to bulldoze my way along.

[Michael Ray Smith]

I have the same problem, with most all of my saws.

I suspect it's technique, where the front of the saw wants to tip downward,
and the angle of attack where the cutting edge of the teeth meets the wood
becomes progressively steep -

like uneven stair height, when you're carrying something heavy.

It's most pronounced, when I'm ripping a board that's vertical in my vise,
or pretty far along my sawbench - my arm wants to swing through a curve
and the sawteeth want to stay in the same plane.

As with most things, I find less force often more persuasive than trying to bulldoze my way along.

Thanks for that tip, Jim. I've sporadically run into the same problem. I've managed to get through by (as you suggest) by using less force, but I've never really been sure exactly what I was doing wrong. I suspect I'm doing the same thing, with my arm swinging through a curve.

Your tip illustrates why this board is so helpful for us newbie Neanderthals trying to learn proper techniques without the benefit of serving an apprenticeship under George Wilson.

[lowell holmes]

Well,

I'm glad that I'm not the only one.

[Mike Allen1010]

I have the same problem, with most all of my saws.

I suspect it's technique, where the front of the saw wants to tip downward,
and the angle of attack where the cutting edge of the teeth meets the wood
becomes progressively steep -

my arm wants to swing through a curve and the sawteeth want to stay in the same plane.

Lowell, lots of great advice here about possible "saw tuning" issues that could be causing your problem.

With regard to technique, Jim, I think you're right on target.

The situation you describe is exactly the reason why a "breasted" (or convex curved) tooth line is particularly helpful -- especially with coarser pitch saws. As your hand and arm move through the the arc that is the natural motion of the sawing stroke (as opposed to linear piston motion) The breasted tooth line maintains a constant angle of attack for the cutting outages were edges relative to the work piece.

Between the set up and technique tips I hope you have a good outcome.

All the best, Mike

[lowell holmes]

Mike,
This has been a great string. I've gleaned a lot of good info from it.

In spite of the fact the saw looks good and straight, when I slid a scrap of mdf down the sides of the teeth, I found two teeth that were sticking out a bit.
I couldn't really feel them but the block found them.

They were not at the problem site though.

I'm going to make the set more consistent and see what happens.

Thanks to all that responded.

[Chris Fournier]

I have the same problem, with most all of my saws.

I suspect it's technique, where the front of the saw wants to tip downward,
and the angle of attack where the cutting edge of the teeth meets the wood
becomes progressively steep -

like uneven stair height, when you're carrying something heavy.



It's most pronounced, when I'm ripping a board that's vertical in my vise,
or pretty far along my sawbench - my arm wants to swing through a curve
and the sawteeth want to stay in the same plane.

As with most things, I find less force often more persuasive than trying to bulldoze my way along.

I would look closely at Jim's suggestion. There's a lot of "English" going on when we saw by hand. Quite simply oversimplified: be loose, let the saw flow with gentle guidance. A hard hand will net poor results.

[Jim Matthews]

Your tip illustrates why this board is so helpful for us newbie Neanderthals trying to learn proper techniques without the benefit of serving an apprenticeship under George Wilson.

I'm not fit to be mentioned in the same sentence with George Wilson.
He's already forgotten more than I'm likely to ever learn.

I'm only familiar with this problem, as I make the same mistake at least once in a session.
This problem is one of the reasons I'm migrating toward lighter saws, and heavier planes - I want inertia working for me.

[Mike Holbrook]

I have a couple saws that like to stick at specific places along their blades. In my case I believe the issue is related to small kinks in the edge of the blade. Sometimes owners or those attempting to restore saws for sale in a hurry use a hammer to roughly straighten blades which have been bent. One of my saws has clear hammer marks near the edge. Another saw just has a very hard to see little kink. With all the discoloration on the edge of many older, restored saws it can be very difficult to see small kinks near the edge of the blade.