# Is it even possible to buy flat plywood?



## 9saws (Jan 31, 2015)

Hello there. I'm new here. Nice to meet you.

Is it even possible to buy flat 1/2" fir plywood nowadays? The last piece I bought came from the local old-line lumberyard, who you would think has reputable stuff. A lot of pieces bowed and twisted. I tried clamping them up with beams and blocks to bend them the other way, and leaving them indoors surrounded by air for weeks. No dice. They were incorrigible.

I've seen a few straightening methods in YouTube but after this, I'm not sure I believe them. Anyway, if you wanted a reasonably flat sheet of 1/2" fir plywood, where would you go or what would you do? I want fir for reasons which we can ignore for this discussion.

Thank you kindly.

9

PS I'm in Durham, NC, USA if you have any hot leads.


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## ssnvet (Jan 10, 2012)

The ability of plywood panels to stay flat is directly dependent on the number of veneer layers.

I've never seen Fir plywood made in any other grade than construction sheathing, and 1/2" has 5 layers of veneer. Also, you will have voids in these layers.

By contrast, 1/2" Baltic Birch has 9 layers of veneer and zero voids.


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## RogerM (Oct 31, 2011)

Not sure why you need perfectly flat 1/2" plywood sheets but you are fighting a loosing battle with 1/2" fir plywood. Have you considered Medium Density Fiber Board (MDF)? Large sheets of wood is never stable so you have to deal with it. As stated by Maniac Matt one of the methods in dealing with it is to laminate it.


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## MrRon (Jul 9, 2009)

Baltic Birch plywood is reasonably flat, but not perfectly flat. No plywood is perfectly flat, so you have to learn to live with that fact.


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## Loren (May 30, 2008)

Look for a plywood dealer. They serve the industry and are
pleasant to deal with. The quality of plywood available
at big box stores is spotty. I see great old 1/2" plywood when
I salvage materials sometimes but the grade of stuff I've
seen at Home Depot is a far cry from it.

For 3/4" you can get hardwood ply with 1/8" MDF plies inside,
usually 2 I think. It's quite satisfactory and flat enough. Of
course it's a cabinet grade material so while not expensive
it's not cheap either. I haven't looked at 1/2" stuff like this


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## 9saws (Jan 31, 2015)

Thank you for the nice replies!

To batch-respond:

I've never seen Fir plywood made in any other grade than construction sheathing…

Oh, sure you have.

Not sure why you need perfectly flat 1/2" plywood sheets

I think I said "reasonably flat" I'm building boxes, not nailing it to studs.

Have you considered Medium Density Fiber Board (MDF)

Actually, that's what I want to move away from. It's an acoustic issue that you just have to trust that I know what I'm doing.

Baltic Birch plywood is reasonably flat, but not perfectly flat

Of course that's a go-to, and I love the stuff, but right now I want to use fir.

Look for a plywood dealer.

Huh. Interesting idea. Thanks.

The quality of plywood available at big box stores is spotty.

"Spotty" is a polite word, but I always appreciate and applaud politeness. The world needs more of it.

Best,

9


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## Ghidrah (Jan 20, 2015)

Luan 1/2" ply is pretty good, I use it often for shop cabinets and jigs. If ply had been sitting in a curved position at the lumb yd for an extended period, (months and months) it'll end up taking the shape of the curve.


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## tomsteve (Jan 23, 2015)

Hiigher quality ply bring higher price and when ya see he price for that higher quality fir ply you just might go to birch, maple, or even oak.
Search the yellow pages for plywood.
Look up custom cabinet builders and ask wher they purchase their plywood.


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## Loren (May 30, 2008)

Have you considered 1/2" lauan ply?

I haven't looked for it lately. It's pretty stable, flattish
and not pricey. I used to get it at HD but I don't know
if they still sell it.


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## patcollins (Jul 22, 2010)

My Lowes sells something called Arauco Ply and it isn't bad. Its not Baltic Birch by any means but it is a whole lot better than the other stuff they have and the price is reasonable.


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## Dan658 (Dec 3, 2014)

> The quality of plywood available
> at big box stores is spotty.


To say the least…. I mentioned it earlier today in another thread, but I found a utility knife blade laminated in a sheet of birch from Rona (a Canadian home Center) by cutting through it with my table saw. Imagine my surprise when sparks started flying out of the sheet as I ran it through. Quality…..


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## 9saws (Jan 31, 2015)

"...but I found a utility knife blade laminated in a…"

Wow…


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## Loren (May 30, 2008)

I say it's spotty because I have bought a lot of satisfactory
stuff at big stores, though the 1/4" ply is not worth the
name, imo. Just junk now, gotta remember that.

Sometimes I only need a couple of sheets and I don't 
want to deal with treking out to the good sources. I
don't always regret buying my ply at HD or Lowe's but
I know I can't do a bookcase job with 1/4" ply backs
with the junk they're stocking these days. I'm going
to buy 1/4" veneered MDF in the future from a plywood
dealer.

In terms of the 3/4" cabinetish ply and MDF HD sells,
it's adequate for many jobs.

Also, in my experiences plywood dealer pricing is often
a pleasant surprise. They have never beat me up for
buying a couple of sheets.


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## realcowtown_eric (Feb 4, 2013)

A lot of plywood is made offshore, so it comes to NA with various moisuture levels. It's mpt unusual ot see the top sheets curled up to levels suitable for boat building. Baltic birch, why that's oventimes out of square.

And fir ply does come in GIS, not just sheathing

Ply from the borgs is often sorted through, starched and damaged, and you've got someone elses "leavings" 
There is no simple solution

I've found bullets in wanut, silica inclusions in teak lumber and various metal inclusions in MCP

Point is u never know what yu fnd.

Eric


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## Garbanzolasvegas (Jan 15, 2015)

Christ even if it's FLAT they all come with more narrow dimensions. Hell none of the specs are even close anymore. 3/4 of an inch could means "anything". I made the mistake of buying some 3/8s inch stuff and never measured it and dadoed my stock to fit it!

It made great firewood


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## 9saws (Jan 31, 2015)

Oh yeah, the last box I built had two different versions of 1/2" in it….


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## MrRon (Jul 9, 2009)

> My Lowes sells something called Arauco Ply and it isn t bad. Its not Baltic Birch by any means but it is a whole lot better than the other stuff they have and the price is reasonable.
> 
> - patcollins


I've used Arauco plywood and it is a pretty good product. It is imported from Chile.


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## 9saws (Jan 31, 2015)

> My Lowes sells something called Arauco Ply and it isn t bad. Its not Baltic Birch by any means but it is a whole lot better than the other stuff they have and the price is reasonable.
> 
> - patcollins
> 
> ...


Lowes is the last place in the world I would go to, but if you're sayin', I'll go look.


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## RockyTopScott (Nov 16, 2008)

You can get Columbia Forest ply at BORG.

It is a pretty decent product.


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## lateralus819 (Mar 24, 2013)

Arauco is good stuff for the price. We use it by the thousands at work.


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## 9saws (Jan 31, 2015)

> I say it s spotty because I have bought a lot of satisfactory
> stuff at big stores, though the 1/4" ply is not worth the
> name, imo.
> 
> ...


I wonder what's inside that veneer 3/4" that HD sells. If it's fir inside the veneer, that would be interesting to me.

I want to pursue fir because of its resonant properties. MDF wouldn't do, birch wouldn't do. This is kind of an experiment but after 49 years I have a little bit of a handle on what I'm looking for.


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## exelectrician (Oct 3, 2011)

Yep!..... Midway plywood south Everett has flat baltic birch, absolutely NO voids or overlaps.


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## 9saws (Jan 31, 2015)

You know, if voids is what you're concerned about, Marine Fir Plywood is marine in part because it allows no voids…The local yard advertises it….hmmmm….


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## bobro (Oct 24, 2014)

They use A-A marine fir plywood in aircraft, so I imagine you could get it online.

lessee…

http://www.aircraftspruce.com/catalog/wppages/royalmarine.php

yip, even comes in smaller sheets and quantities. hmmm… those guys also have basswod ply and milspec mahagony ply, rock and roll.


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## paxorion (Oct 19, 2012)

> I say it s spotty because I have bought a lot of satisfactory
> stuff at big stores, though the 1/4" ply is not worth the
> name, imo.
> 
> ...


I've had varying results with the HD plywood. My local HD stocks Columbia Forest made in USA products and lately Lowes started too. The 3/4 is 7-ply and 1/2 is 5-ply veneer core (if you count the top veneer layer) and seems to be poplar from green tint. The plys are thin and for paint or unstained clear coat, the plywood has given me different but acceptable results. Having checked the local hardwood dealers and their paint-grade plywood is comparable in plys and price.


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## KDO (Oct 26, 2010)

There should be good wood suppliers around you. They supply all the cabinet makers and furniture makers in town.
My brother is a one-man cabinet shop in Colorado, and he has several places that he buys could sheet goods from.
Like someone else mentioned, if you can't find them, go to a cabinet shop or two and ask them where they buy there wood. Most of them will probably tell you. 
And, like someone else said, they aren't always anymore expensive than anyone else.
It is definitely worth doing some research on.
The big box stores sell only "what sells", and if they don't have any demand for it, they won't stock it.
You might even try looking on the websites for lumber companies like Boise-cascade or Weyerhauser and see they list as distributors.
Good luck.


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## Ripthorn (Mar 24, 2010)

If you are buying from the BORG, then even if it is fir faced, you likely won't have fir all the way through. You are also likely to have voids and lamination problems from the glue. This will wreak havoc on its acoustic properties. If you want to try fir for its resonant properties, then I would get some nice fir from a wood dealer, slice it up thin, and make my own ply with alternating laminations. Use a veneer press to press it all together, and you are guaranteed to have it void free and flat. A good hard glue like hide glue will minimize losses into the structure that are not due to the wood. I only suggest this very labor intensive process because you mentioned acoustic properties, and, being an acoustic physicist, I have an obligation to recommend not using off the shelf fir ply . Fir is generally seen as cheaper, so they don't apply the same construction standards to it that they do for Baltic birch, which means I would not trust it acoustically as far as I could throw a pallet of it.

Alternatively, you could also look for HDF, which is more rigid than MDF, but more costly and harder to find. Are you making speaker enclosures?


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