Sawing through birch plywood, don't want to damage veneer

[Rob Schwartz]

Hi all,

I am working on building a toolbox out of birch plywood (23/32). I'm afraid that sawing it (hand saw) will mess up the pretty veneer on the edges. I've heard that this can be an issue. How should I combat this, or does it not matter?

Thanks,

Rob

[Mel Fulks]

Put a strip of tape on the bottom side of a scrap and see if that helps.

[Pat Barry]

Are you really talking hand saw, or do you mean circular saw? I read somewhere that pre-scoring the exit side with a razor knife was a good way to help prevent tearout. I tried this once and did not get the pre-scoring exactly right. I think its a technique with merit but it requires very careful measurement on both sides to get the lines correct. Otherwise, I had luck with a zero clearance insert on my table saw, and a similar zero clearance plate for my circular saw (a 1/4" thick piece of masonite double back taped to the bottom of the circular saw plate. I think the correct answer for the power tool route is a combination of zero clearnce adapter and a saw blade intended for veneer plywood cutting. For manual sawing I don't know but you might be able to have a backer piece to help support the cut edge but of course thats just more material to cut through as well.

[Rob Schwartz]

Yup, I'm really talking hand saw! I want this project to be able to be completed by people who have only a hand saw, so I'm doing it with a hand saw myself. I agree about the scoring- it does sound tricky. I can post some results of a test cut today or tomorrow.

[Lee Schierer]

You might want to post this on the neander forum, but in my opinion you are going to get significant tear out, particularly if you use BORG plywood, even with a very sharp hand saw. Taping the bottom side with masking tape (painters tape is not sticky enough) might reduce the chipping of the veneer. When you remove the tape be sure to peel it toward the cut line. Pulling it away from the cut line will lift any loose areas.

A Japanese push pull type saw might give you less tear out.

[Rob Schwartz]

Okay, so I tested out a hand saw on a scrap piece and the results aren't pretty, to say the least. The top looks permissible, but the veneer is messed up and the bottom tore out, even with tape. So what should I do if I am going to use a circular saw instead?

By the way, thank you all for your helpful suggestions. I'm hoping that all of this discussion pays off before I make the actual project. :)

[Mike OMelia]

You might want to take the implied advice above and consider a higher quality plywood

[Ron Kellison]

I would point out that the old-timers who were doing this entirely with hand tools were not working with plywood. That said, I would use a good straightedge and a sharp marking knife to score BOTH edges of the cut before I tackled it with the saw. It would also be worthwhile to use a saw with fine, sharp teeth.

[Rob Schwartz]

Mike, I would go with something higher quality, but I want to keep the price down. Thank you for the suggestion, though.

Ron, does that apply to circular saw blades also? Would you recommend using a circular saw blade with fine, sharp teeth?

Thanks,

Rob

[Tom Blank]

If you go with a circular saw, consider getting a quality blade for it specifically ground for plywood such as the Forrest Hi-AT.

[Charles Lent]

A circular saw with a blade that is designed to cut plywood (many fine teeth) and a zero clearance insert type saw shoe is how I do this. My saw shoes are made from 1/8 - 1/4" Lexan the size of the whole foot on the circular saw, and I bolt these in place with two flat head bolts, one in the front and one in the rear of the saw foot up through the foot from the bottom and countersinking the holes in the Lexan enough to keep the heads of the bolts recessed and the bottom of the lexan flat and smooth. I plunge cut a blade slot through the Lexan and then mark the area where the Lexan interferes with the blade guard function. Then I remove the Lexan and cut out this marked area, being careful not to remove the area ahead of where the guard moves. This area is where the blade teeth rise up through the Lexan, and where this Lexan shoe prevents the blade teeth from lifting the wood fibers on each side of the saw cut. Then re-attach the Lexan shoe to the saw foot using the flat head bolts and make certain that the blade guard can operate correctly. You have now completed the build and installation of this zero clearance insert. When this blade and zero clearance shoe are mounted on your circular saw you should be able to cut Baltic Birch or other plywood and have very little, if any, tear out, but the area where the teeth rise up at the leading edge of the cut must be kept close to the blade. If it wears or you use a different blade will need to make a replacement shoe.

Charley

[Jim Matthews]

I would point out that the old-timers who were doing this entirely with hand tools were not working with plywood. That said, I would use a good straightedge and a sharp marking knife to score BOTH edges of the cut before I tackled it with the saw. It would also be worthwhile to use a saw with fine, sharp teeth.

Ron beat me to it.
This is the way I was taught.

Score all the way around.
I use TWO PARALLEL LINES and saw between them.

The first knife pass can be very light, with a sharp blade.
I recommend clamping the straight edge used to the sheet goods.

Once you have established a line, you can score quite deep.

I use a simple crosscut saw to break down smaller pieces, suitable to make a tool box.


I've taken to a method where you remove all but the outermost two plies,
and form a sort of rabbet on the end. Once glued and dried, the thin ply can
chamfered at the edge to hide the joint.

This not only makes alignment easier during the glue up, it also makes for a tight joint.
I would not leave this as the only structural component of a toolbox.

Corner blocks, gussets or some kind of internal webframe should be considered as
a complement to the glue. 284620

[Rick Potter]

I have a Freud 10" blade that is labeled "melamine both sides". Wouldn't be surprised if they made a 7 1/4 for that too.

Rick Potter

[lowell holmes]

Amazon has 7" plywood blades for circular saws. They cost less than $10. IIRC, they work.

I haven't used one in 30 years. I bet you can buy one at the BORG.

[Chris Padilla]

Using a track saw (DeWalt, Festool, Grizzly, etc.) can achieve very clean, sharp cuts in plywood. I have the Festool track system and I get exceptionally clean cuts in plywood but it is well-designed to do this...but it is pricey. However, you can still do it with a regular circular saw AND a good sharp, high-tooth blade designed for crosscutting plywood. You simply make up your own track/guide with a couple pieces of plywood and you use your saw to trim your shop-made track/guide to give it zero-clearance.

[Michael Mahan]

depth of blade & angle of attack helps as well on a circular saw , fine tooth blade with just a 1/8" over on the depth help loads

[Greg Hines, MD]

Using tape, and a guide for your saw, and a sharp blade, and scoring the veneer, will all help. Probably best to do them all. I made my own guides, out of 1/4" hardboard, a plywood strip down the middle, and a t-bar on the underside to keep it square. I use a circular saw all the time to deal with this, and it works for me. See my photos for some pics of my guides.

Doc

[Jamie Buxton]

Have you considered using MDF instead of plywood? You can cut it with a hand-powered saw without chip-out.

MDF brings its own issues, so using it instead of plywood might or might not be feasible depending on what you're building.

[John TenEyck]

Score both sides, as recommended. But then cut it long so that any tearout stops at your score lines. Now put the board on a shooting board and hand plane the cut edge down to the score marks. Just like they used to work wood by hand.

John

[Roy Turbett]

Has anyone ever tried backing up the plywood with something like MDF or foam board? I know some guys use foam board as a backer when cutting plywood on the floor with a circular saw but wonder if this would work with a hand saw too. Its the same idea as a zero clearance insert on a tablesaw.

[johnny means]

First of all, tape on birch ply is a bad idea. The tape will tear fibers right out of the veneer when you removed it, even painter's tape. Scoring with a knife is the way to go. But, you can't cut right on the score mark, you need to cut just shy of the score then hand plane or block sand to the line. I would avoid doing this type of work in the shop at all cost (much easier to make and use a saw track), but it's saved my butt on a job site a few times.

[Mark Wooden]

With the tools you want to use, change to solid stock. Pine, bass, poplar, oak and maple have been used for tool boxes for centuries.
If you insist on using ply, with a skill or jigsaw, score the top,leave the line and plane to size. If using a handsaw, score both sides and clamp a straight edge on the line on both sides so you don't wander and tear it out and then,again, plane to size.

And then, if using hand tools on plywood, be prepared to sharpen your tools frequently- the glue and particulates in it dulls tools fast. I won't use most of my hand tools on it because of it.

[Jim Matthews]

Has anyone ever tried backing up the plywood with something like MDF or foam board? I know some guys use foam board as a backer when cutting plywood on the floor with a circular saw but wonder if this would work with a hand saw too. Its the same idea as a zero clearance insert on a tablesaw.

I cut all my sheet goods on a hard insulation board.
I still get chip out, when I use my circular saw.

Scoring two parallel lines confines the chip out, some.
With a better blade - finer finishes can be achieved.

Those come at too high a price for my occasional use.

[John TenEyck]

I cut all my sheet goods on a hard insulation board.
I still get chip out, when I use my circular saw.

Scoring two parallel lines confines the chip out, some.
With a better blade - finer finishes can be achieved.

Those come at too high a price for my occasional use.

The Freud Diablo thin kerf blades generally cut with minimal tearout when I cut hardwood veneered plywood. In most cases, even the exit side of the cut (top) is nearly perfect. I think I paid about $10 for a 7-1/2" diameter one at HD.

John

[Jim Matthews]

$10?

I thought my new computer was cheap.
What's that, two lattes at Starbucks?

Which blade?

Freud LU79R007 - $48

[Rob Schwartz]

Hi all!

I took the advice and went with poplar wood- It's lighter and easier to work with :)

I finished the project last night, and here are some pictures:

287122287124

I am making a guide online on how to do the entire project, and I'll post a link here if anyone wants a peek.

Thanks again,

Rob

[Rob Schwartz]

All right- here it is:

http://www.instructables.com/id/Functional-and-Sturdy-Wooden-Toolbox/

Rob

[Justin Ludwig]

Simple, functional, and has a hairy chest (pun intended) look to it. I hope it helps out someone looking to explore DIY toolbox options! I like it. Good job, Rob.