The reliability of Proofgrade materials

I was thinking…make a longer jig and do several at a time…one long cut over 4 or 6 at a time…:smile:

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And keep a dampened Q-Tip on hand so when you tilt the 2 pieces together you can run a quick swab down inside the resulting corner. Only dampen one end so you can follow the damp wipe with the dry end to clean up any residue.

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I agree. fire up the router and buzz down several pcs. you could even make a double sided jig and do 2x as many in one clamping process.

Fantastic post on so many levels!
Great to see the consistency on that volume.
Neat trick for glue up.

On the routing, would a router table make it faster, or do you feel the jig is more accurate? While i have a router and small table for it, I rarely use it( don’t have a dedicated space for it and always a pain to set up etc). May be needing to make a door for the new workshop, so it might actually get some work with it soon.

Maybe I am in the dark, and maybe this has been discussed somewhere else but looking at the router cut, I am noticing the material (PG plywood) looks to be veneered MDF. Am I correct or is my vision screwy?

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How in heaven’s name can you see that from the picture?

The particle density in the PG plywood is very uniform with no knots and a thick finished veneer on both sides. Cuts like butter.

Similar to the draftboard, which is also very uniform, but no veneer.

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With “Laser” vision of course! So it is a mdf product with a wood veneer, not multiple layers of wood like regular “ply” wood? I’m cool either way just wanted to know what to expect. Thanks @Jules! You are churning out great stuff btw, keep up the good work!

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Thank you kindly! (I’m no expert, so I’m not sure what differentiates MDF from plywood.) :stuck_out_tongue_winking_eye:

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MDF is essentially compressed cardboard fibers. Plywood is glued layers of wood that are in 90 degree orientation from each other.

This is a quick and dirty definition of the two, I’m sure others will elaborate further :wink:

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Yes I don’t know why GF call veneered MDF plywood, it isn’t.

As a matter of interest, is the grain on the two veneers at right angles?

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No. Grain same direction. Would screw up some designs if it was at right angles. MDF as a center ply kind of negates any reason to do otherwise.

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What @Jules said is correct, MDF core with real wood outer plys.
It cuts super consistent and with the outer plys is just a bit stronger than plane MDF.

When strength is more important than appearance go with Baltic birch. I use bb in both 3 and 5 mm and it works great. I hope :glowforge: will eventually release a :proofgrade: Baltic birch.

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I’ve bought some thin “plywood” from local stores that seems to be made the same way, which is why I wasn’t sure. (Maybe that’s how they do it here in America.)

I’d certainly expect something labeled plywood to be constructed from veneers stacked in alternating directions. For some applications you need the added strength that provides.

I’m not sure what I’d call MDF with veneers on the outside. For most purposes, it’s probably just as good as plywood. I’m sure it cuts more consistently and you’re not going to find any hidden surprises inside, so in a lot of cases it may actually be better. Just surprising if you’re expecting actual plywood.

But if you need the strength of plywood, I’d look for the real thing. Just keep in mind that the real thing often has hidden surprises.

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No.

It’s weird.

Sure, ok, the mdf core can be considered a layer, and three layers counts as “plywood” I guess. It’s a stretch, but GF has been pretty… stretchy… with lots of terms.

I agree with @tim1724 here: something labeled plywood is expected to be constructed from veneers stacked in alternating directions.

At least it is thin and we can build 3/4" Proofgrade Plywood plywood, by stacking three sheets of 1/4" PG in alternating directions.

PG looks really nice. Nicer than most pre-sanded ply you might find. I would be interested to see some strength tests of layered PG ply vs standard 3/4" ply. Boxes are one thing, but what about chairs and stairs and all the rest? I want to see destructive testing.
(I am also happy to perform destructive testing…)

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It’s gonna require work to do that. The finish on the wood veneers doesn’t love glue - you’ll need to sand the glued surfaces first before stacking & clamping.

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One word:
MechanicallyFastened

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Just use the Draftboard. That stuff is freaking awesome! (Did that with the center bar on the Jester toy.)

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I can tell you from experience that proof grade plywood is not that strong, if you need some real strength use three layers of quarter inch Baltic Birch.

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…But I don’t wanna use imported materials! :persevere:

Actually, do we know where PG materials are being produced, or where the woods are sourced from?