Why I am breaking coping saw blades?

[Gordon Sindelar]

hello, longtime reader, first time poster. been building my neanderthal tool and skill set for about a year now. really enjoying myself.

However, i'm having a lot of trouble with the coping saw. i'm using it to cut curves in quarter sawn sycamore, so the wood is not terribly difficult. I only cut about 6-10 inches before the blade breaks. i can't believe this is to be expected. something has to be off, but i'm not sure what.

the saw is an older standard hardware store design. it doesn't reek of quality, but it doesn't seem like junk either. I get good tension on the blade when it is initially inserted into the saw. i'm using stanley 15 tpi blades new from the hardware store.

I can only believe it is one of two things: the saw is prematurely losing tension on the blade causes stress and breakage, or it is my technique. I tend to saw fast and aggressively, but as I said, even with moderate aggression, the blades seem to be breaking way too fast.

I've had my eye on the knew concepts saw, but I frankly don't want to drop $100+ on a coping saw if I don't need to.

Any advice is greatly appreciated to solve this issue!

Gordon Sindelar.

[David Weaver]

If you're breaking coping blades, you'll go out of your mind with fretsaw blades. Unless knew concepts makes coping saws, my bad if they do.

If you're cutting curves, it could either be that you're using a saw that does lose tension too fast, or it could be that you're applying a lot more binding pressure on turns than you need too. that's unproductive pressure that increases the tension on the blade and doesn't increase the speed or quality of the cut. If you find that you're often far away from your line or constantly correcting, it's probably a matter of too much influence on the saw.

In the curves, work the saw with a little more speed and a little less pressure, and think of the turn as you're pointing the blade in the direction you want it cut rather than twisting the saw to force the blade. Move the frame with a little less force and keep the amount of the cut a little less until you get the touch and it feels like you're working with a trained horse that goes where you're thinking with little influence rather than one you have to lean into.

You should essentially be able to use them until they're dull unless stanley blades are complete junk.

[Tom Stenzel]

Do you have the blade mounted so it cuts on the pull stroke? No one had ever told me that, I figured it out one day on my own. When I was cutting with the blade on the push stroke my blades would break all the time.

My skills with a coping saw are still shaky but at least I don't break blades like I used to.

-Tom Stenzel

[David Keller NC]

My thought is that you're aggressive enough to be building quite a bit of heat on those blades. It's also possible that you got a bum pack of blades that are too hard (and therefore brittle).

Try this: saw like mad for about 2 inches, then take the saw out of the cut. If the blade's so hot you can't touch it, then you've largely a technique issue (too aggressive) or a "set" issue, where the saw teeth have insufficient clearance between the cutting edges and the blade back. Also, keep in mind that if you are indeed heating the blades up excessively, then your original high-tension set-up is now loose from the blade expansion.

You might also consider lubeing the blade - get a piece of candle or canning wax, and drag your sawblade through it right before you go into the cut. If it's working, the sawing should be considerably easier, and the blade far less hot when you take it out of the kerf.

[David Weaver]

With the paraffin or whatever other lube, you can certainly tell if the blade is getting too hot. If sawing is getting the blade to the smoke point of paraffin, there's too much binding or perhaps a coarser tooth is warranted.

[John Coloccia]

I can honestly say that I can't remember ever actually breaking a coping saw blade. I've abused them and bent them but that's about it. Maybe just try some different blades? It could certainly be your technique. Everything David says is valid. I just can't imagine that you're able to consistently break coping saw without doing something obviously incorrect and abusive unless you have some bad blades.

[Gordon Sindelar]

Thank you to everyone for the advice, extremely useful. In response:

The blades are oriented to cut on the pull stroke.

The blade does get very hot. So hot that it burns the skin on my hand to the touch.

I will be trying the methods suggested herein. Thanks again.

By the way, any recommendations on a maker of blades other than the stanleys?

[Jessica Pierce-LaRose]

Olson blades are my favorite. I've been getting them from Tools For Working Wood, but I've found them a couple places locally, as well. I think the 16tpi skip-tooth is what I use for most of stuff (sawing out dovetail waste mostly). I know it's a skip-tooth, maybe it's 18tpi?

[Jim Koepke]

Gordon,

Welcome to the Creek. Your profile doesn't indicate where you are located. You may live near another member with the New Concepts saw that would be willing to let you take a test drive.

My revelation with fret saws came by using a spiral blade from Lee Valley.

http://www.leevalley.com/us/wood/pag...884,42904&ap=1

These didn't break as often as the straight blades. It seems turning the blade before the teeth are going in that direction can stress the blade and cause breakage.

Also if the blade is bowing in a cut, it is being stressed by being pushed too hard into the cut.

jtk

[jason thigpen]

I've been using the el cheapo Buck Brothers variety pack from the Borg. They cut clean and I haven't broken one yet.

[David Weaver]

I've been using the el cheapo Buck Brothers variety pack from the Borg. They cut clean and I haven't broken one yet.

That's what I've been using, too.

[Jim Neeley]

Gordon,

What is the thickness of the stock that you are sawing? If it is not thin you may need a skip-tooth blade to carry away the sawdust and permit the blade to remain cool.

Jim

[Sam Stephens]

fwiw, i cut w/ the push stroke. i find it easier to control as it's more like all my other saws. mine is the blue borg version but i doubt it's much different than the orange borg one.

[steven c newman]

Wore out the stanley blades, trying some by Kobalt. Might have to try the Olson ones. SDC14318.jpgJust some older saws, still work though.

[Gordon Sindelar]

Gordon,

What is the thickness of the stock that you are sawing? If it is not thin you may need a skip-tooth blade to carry away the sawdust and permit the blade to remain cool.

Jim

Jim, it's 3/4 stock that I'm cutting. Nothing crazy.