Best method to cut ply?

What's the most accurate and efficient way to cut 1/8" to 3/16" ply for a glider fuselage? I'd imagine using a utility or hobby knife would take forever and burn up a lot of blades, and I don't have any power saws (which would probably splinter/tear up thin ply like this). I'm new to this so any help/advice would be greatly appreciated.

For hand tools and straight cuts with a thin kerf, a razor saw does a nice job.
For curved cuts using a template and pattern following bit it’s hard to beat a trim router.
Google “how to cut veneer”

3/16" is a bit hefty to be cutting with a knife, but it can be done. Use a steel straight edge as a guide and go slow. Trying to rush and make deep cuts results in nasty red stains on the wood.
A bandsaw or table saw with a sharp blade is the best. To prevent splintering on bottom have the good part on top of a sacrificial piece.
I know you said you don't have power tools, ask around your local club if someone has a saw. A local cabinet shop (smaller the better) may cut it, it's amazing what you can get showing up when a shop opens with a box of doughnuts.

M

Coping saw. Cheap and works well with straight or curved cuts.

Took this shot this last year, while cutting parts for the motor pods for a 3X Gyroc Upscale. Pretty sure that is 3mm hobby grade plywood I was cutting.

The curved-blade veneer saw at the top of the image, just above the aluminum angle I was using as a straight edge, is good for making short straight cuts in thin plywood. The jeweler's saw, with a push-pull blade is good for cutting centering rings, etc (the tabs on the rings here were intended the rotor flaps on the Gyroc straight, until the pod ejected).

For longer, straight cuts, a short dozuki panel saw or a Zona pull saw will work well on thin plywood.

Coping saws are cheap and will do the job. About $8 at Lowes. Practice first; they can be a bit tricky for newbies. The blades are thin and flexible so they can do curves. They don't always go where you think they should as you try to turn.

Much thanks gents! Learned a lot--I've never heard of some of these cool tools (dozuki panel saw & Zona pull saw) but it sounds like something fine-bladed with a lot of tooth count is what I need. You've given me a lot to consider and I'll do a few practice runs with my razor saw to get a feel for cutting technique first. I'm leaning more toward a 32-tooth coping saw or dozuki panel saw.

Zeus-cat said:

Coping saws are cheap and will do the job. About $8 at Lowes. Practice first; they can be a bit tricky for newbies. The blades are thin and flexible so they can do curves. They don't always go where you think they should as you try to turn.

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There are spiral blades sold for jewelers saws (which are also sometimes sold as fret saws) which cut in every direction -- making it easier to cut inside corners and small radius curves.

Spiral Fret Saw Blades at Lee Valley

I have a "Japanese pull saw" that I bought at Home Depot a couple decades ago. It looks like a Dozuki saw but has no backing on the blade, rather it has finer teeth on one side and coarser on the other. It works great for cutting without tearout. I have a fair amount of power tool options, but I still use it a lot in the winter when I want to work in the warmth of the kitchen.


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Just an update: I bought a 32-tooth coping saw and tried it on 1/8" birch ply but the results are far from what I hoped it would be. There was a fair amount of tear out even though I taped the edge and clamped the ply sheet to a 2x4 support. My razor saw has finer teeth and had better results except the reinforcing spine on it limits how far I can cut (about 1/2 inch).

RocketFeller said:

I have a "Japanese pull saw" that I bought at Home Depot a couple decades ago. It looks like a Dozuki saw but has no backing on the blade, rather it has finer teeth on one side and coarser on the other. It works great for cutting without tearout. I have a fair amount of power tool options, but I still use it a lot in the winter when I want to work in the warmth of the kitchen.


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I think that's what I need, something without that reinforcing spine to limit cutting depth. Can you recommend a brand?

Rktman said:

I think that's what I need, something without that reinforcing spine to limit cutting depth. Can you recommend a brand?

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The spine is less of an impediment than you might expect, and it helps with making straight cuts. The height of the blade is much greater than the thickness of the stock you are proposing to cut. The saw is is held at a shallow angle while making the long cuts, which puts more teeth in contact with the stock and puts a wider section of blade in the cut -- making it easier to keep the cut straight. Its only when you are starting and finishing the cut that you hold the blade nearly perpendicular to the face of the stock, which is when you use the part of the blade the protrudes beyond the spine. There are lots of "how to" guides on line for this.

I think the style of saw Rockefeller is describing is called a ryoba.

I think my dozuki is a Gyokucho. Vaughn and Bushnell sell a couple different styles of made-in-Japan, Japanese-style back saws under the "Bear" label. They are good enough, as far as I can tell. I haven't looked to see if they still sell them, but I bought a Bear ryoba blade at Lowe's. I mounted it in hickory hammer handle (that'd split badly enough that I didn't want to use it to bang on metal anymore). Probably 10 years of light-duty cutting and it is still sharp.



The Bear ryoba is a rip saw on one edge and a cross-cut on the other. Not that this would matter all that much for cutting plywood, but the teeth of the rip-saw side decrease in height and pitch as you move towards the handle. The idea is to start the cut with the coarse teeth at the front of the blade, then move the blade further into the stock so that the finer teeth (and stiffer section of blade) will carry the cut. Again, the idea is to make it easier to make long straight cuts.

If you want to cut curves this is the wrong tool. A coping saw, or a fret saw, is what you want.

Rktman said:

I think that's what I need, something without that reinforcing spine to limit cutting depth. Can you recommend a brand?

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I will look tomorrow, I'm on my way to our club's annual meeting. I don't recall it being branded, but there is probably something etched on the blade.


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Rktman said:

I think that's what I need, something without that reinforcing spine to limit cutting depth. Can you recommend a brand?

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The one I've got is Irwin (brand). As mentioned, it has crosscut on one side and rip on the other (pitch and type of teeth are different). I'm assuming I bought it at Lowes. The other one I had is called a "Shark" Saw (brand).

if I recall, the reinforcing backing is removable on the 'X-Acto' brand.. OS, buy a blade, rip off the spine, and go!

and, the X-Acto blades are about an inch deep, if you hold / cut at a shallow enough angle, the backing wont get in your way. of course, you'll be cutting with eth end inch or or so..

Rktman said:

Just an update: I bought a 32-tooth coping saw and tried it on 1/8" birch ply but the results are far from what I hoped it would be. There was a fair amount of tear out even though I taped the edge and clamped the ply sheet to a 2x4 support. My razor saw has finer teeth and had better results except the reinforcing spine on it limits how far I can cut (about 1/2 inch).

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There are different widths of razor saw blades;

https://www.widgetsupply.com/category/X-ACTO-razor-saw-blade.html

The widest I've found is about 1 1/2". What *I'm* looking for is a depth stop for a dozuki/ryoba/gyochuko. I'm looking at starting making kumiko, and need to make precise depths of cuts for a dado for a lap joint.

Rktman said:

Just an update: I bought a 32-tooth coping saw and tried it on 1/8" birch ply but the results are far from what I hoped it would be. There was a fair amount of tear out even though I taped the edge and clamped the ply sheet to a 2x4 support. My razor saw has finer teeth and had better results except the reinforcing spine on it limits how far I can cut (about 1/2 inch).

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What kind of cut are you trying to make?

You shouldn't be getting much tear-out with something as fine as a 32 TPI coping saw blade. Keep the blade inclined at something less than 45° to the face of the wood, and don't work too hard -- "let the saw do the work" as they say.

Also the spine on the razor saw really shouldn't stop you from making long cuts in 0.125" stock. The blade shouldn't be perpendicular to the face of the stock you are cutting. I just ran down to the shop and made a quick cut on some 1/4" scrap with a Zona saw -- probably not too different from your razor saw.

This is it. It is a Sharksaw brand.


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jlabrasca said:

What kind of cut are you trying to make?

You shouldn't be getting much tear-out with something as fine as a 32 TPI coping saw blade. Keep the blade inclined at something less than 45° to the face of the wood, and don't work too hard -- "let the saw do the work" as they say.

Also the spine on the razor saw really shouldn't stop you from making long cuts in 0.125" stock. The blade shouldn't be perpendicular to the face of the stock you are cutting. I just ran down to the shop and made a quick cut on some 1/4" scrap with a Zona saw -- probably not too different from your razor saw.

View attachment 335618View attachment 335617View attachment 335616

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I was trying to cut a 14" long x 1/2" strip for a glider fuselage.

Maybe my technique wasn't right. I'm assuming I have to hold my razor saw at a shallow angle (probably less than 45° like in your photos) since I only have 1/2" clearance between the teeth and the supporting spine of my razor saw?

Not sure why I was having so much trouble with the coping saw, whether it was due to the taller, larger teeth vs my razor saw, the angle, or how much pressure I was using.

A deeper blade like one of these pull saws would definitely help.

RocketFeller said:

View attachment 335629

This is it. It is a Sharksaw brand.


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Cool, thanks! Not familiar with the brand but I'll definitely look that up online. Would be great if I could still get something like that at Home Depot or Lowes.

Rktman said:

Cool, thanks! Not familiar with the brand but I'll definitely look that up online. Would be great if I could still get something like that at Home Depot or Lowes.

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An interesting idea. This might work:

https://www.homedepot.com/p/DEWALT-Flush-Cut-Pull-Saw-DWHT20541/203040590

Rktman said:

I was trying to cut a 14" long x 1/2" strip for a glider fuselage.

Maybe my technique wasn't right. I'm assuming I have to hold my razor saw at a shallow angle (probably less than 45° like in your photos) since I only have 1/2" clearance between the teeth and the supporting spine of my razor saw?

Not sure why I was having so much trouble with the coping saw, whether it was due to the taller, larger teeth vs my razor saw, the angle, or how much pressure I was using.

A deeper blade like one of these pull saws would definitely help.

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Coping saws are for cutting curves ( thats what coping <trim> involves). A ripsaw is for cutting straight lines, however a crosscut saw will work somewhat in a pinch. The depth of the blade and length will determine how easy it is to cut a straight line. A razor saw works somewhat like a small ripsaw.

Rktman said:

I was trying to cut a 14" long x 1/2" strip for a glider fuselage.

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If it's just 1/2" x 14" rectangle, then its not a job for a coping saw. For a straight cut that long on stock as thin as 1/8"' I think I'd probably put the work piece flat on a waste board, clamp down piece of angled aluminum for a straightedge and score it deeply with a utility knife. Leaving the straightedge in place, I'd finish the cut with the razor saw held almost parallel to the face of the board. Double sided tape can be useful for holding the straightedge down if you don't have a clamps with deep enough throats.

If its a curved shape I'd use a fret saw, support the piece across two closely spaced boards, and take a really long time to make the cut -- except that I probably wouldn't try to cut a long narrow profile from 1/8" plywood with hand tools. I'd use an X-acto to cut multiple copies from basswood or balsa and laminate them after they'd been shaped.

Rktman said:

A deeper blade like one of these pull saws would definitely help.

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With that saw (that's the 32 TPI blade from the Zona 4-in-1 kit) I would not try a 14" long cut the way I did it in those pictures. But with a straightedge -- should be doable with a boxcutter and an X-Acto razor saw (if that's what you have). Or just with the utility knife, if you don't mind a little splintering on the back side. It'll be time consuming, but doable.
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terryg said:

An interesting idea. This might work:

https://www.homedepot.com/p/DEWALT-Flush-Cut-Pull-Saw-DWHT20541/203040590

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Its short, and the blade is very flexible, for trimming dowels and tenons far from the edge of a board.

jlabrasca said:

Its short, and the blade is very flexible, for trimming dowels and tenons far from the edge of a board.

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It also does not have teeth that go to the edge of the blade. Only the center portion of the blade can be used to make cuts.

terryg said:

An interesting idea. This might work:

https://www.homedepot.com/p/DEWALT-Flush-Cut-Pull-Saw-DWHT20541/203040590

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Took a look online and that particular one just happens to be one of three that I want to go down in person and check out. This larger one from home depot is another https://www.homedepot.com/p/Vaughan-10-in-Pull-Saw-with-Double-Blade-BS250D/100373697

jlabrasca said:

If it's just 1/2" x 14" rectangle, then its not a job for a coping saw. For a straight cut that long on stock as thin as 1/8"' I think I'd probably put the work piece flat on a waste board, clamp down piece of angled aluminum for a straightedge and score it deeply with a utility knife. Leaving the straightedge in place, I'd finish the cut with the razor saw held almost parallel to the face of the board. Double sided tape can be useful for holding the straightedge down if you don't have a clamps with deep enough throats.

If its a curved shape I'd use a fret saw, support the piece across two closely spaced boards, and take a really long time to make the cut -- except that I probably wouldn't try to cut a long narrow profile from 1/8" plywood with hand tools. I'd use an X-acto to cut multiple copies from basswood or balsa and laminate them after they'd been shaped.

With that saw (that's the 32 TPI blade from the Zona 4-in-1 kit) I would not try a 14" long cut the way I did it in those pictures. But with a straightedge -- should be doable with a boxcutter and an X-Acto razor saw (if that's what you have). Or just with the utility knife, if you don't mind a little splintering on the back side. It'll be time consuming, but doable.
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Thanks, definitely worth trying it this way before I invest in any more saws. I'd rather spend a little more time getting a nice evenly clean cut than risk a faster but splintered and uneven result. This is all new territory for me, and I've got more patience than $.

Ahh, long straight cuts.

Question, does it have to be ply? why not use 1/2" x 1/8" basswood or maple. sometimes some specialty stores will have strips already cut (I'm thinking of model boat builders)

And, to take a trick from my mum, who was an avid quilter. you can get a rotary cutter, it;s like a pizza wheel / cutter, but has a round X-Acto type blade..

https://www.walmart.ca/en/ip/fiskars-comfort-loop-rotary-cutter-45-mm/6000052803667

(I just tried it on a piece of 1/16" ply, and it only took 3 passes.. blade is dull & rusty.. mind you, only the corner of a piece of ply..)

Rktman said:

Took a look online and that particular one just happens to be one of three that I want to go down in person and check out. This larger one from home depot is another https://www.homedepot.com/p/Vaughan-10-in-Pull-Saw-with-Double-Blade-BS250D/100373697

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Looking at the specs on that saw, it has the same teeth on both sides (at least that's what the web page seems to imply). A lot of the saws mentioned have a crosscut/rip blade combination. And, yes, the blade shapes *are* different. I found the handle, but not the blade for my Shark Saw, but the blade on my Irwin shows the difference. The rip blade looks like a bunch of chisels lined up, the teeth are cut square to the direction of cut. The crosscut blade has teeth that are ground with alternating bevels to each side of the direction of cut. The Irwin saw also has varied tooth pitch; closely spaced teeth near the handle, and spaced further apart down the blade. This makes it easier to start a cut.