Plywood Void Question

[matt romanowski]

I bought some 3/4" birch plywood yesterday. It's sold as A2 but marked A1. Comes from Rockwell in Canada and is $90 a sheet. When I was breaking it down last night (and I love my Makita track saw for this!), I found the voids show in the photo. I was surprised as I've seen stuff like this is the material sold as shop grade, but I expected this to be better.

I emailed the supplier and they said "The grade of plywood you purchased is an a2-vc. The a2 is the grade of the face veneers (front and back) only. The core of plywood is made up of 4 different grade with grades K and L being the most common sold. These 2 grades do allow voids and overlaps in the core only and can not be under the face veneers."

So, is this what other people see? Should I expect that in this quality material? It probably doesn't matter as the plywood is still straight and flat, but it wasn't what I expected.

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[Doug Hepler]

Matt

I find voids and weak glue joints fairly often in birch plywood. Grades are tricky to use because, as the supplier said, they refer to the face and back plies. Notice that this is 5-ply. To me that always means lower quality, utility grade. If you want better quality 3/4" plywood buy 13-ply Baltic Birch. You pay your money and you take your choice. If you would like to read more about plywood, have a look at chapter 5 of my book, Notes and Reflections While Shaving Wood. An Acrobat copy is available free at http://plaza.ufl.edu/chepler/

Doug Hepler

[Mike Heidrick]

Thicker veneers are less quality??

[Mark Kanof]

Thicker veneers are less quality??

Yes, in general thicker layers in the plywood indicates a lower quality product. This doesn't necessarily work the other way though as you can certainly get "shop grade" baltic birch that has many thin layers, but also has overlapping layers and voids.

To respond to the original poster, my local supplier has 5' x 5' sheets of baltic birch that have 13 layers as Doug indicates above and I have found it to be very consistent, with virtual no voids or overlapping layers. I think the last time I bought some of these they were something like $65 a sheet.

[matt romanowski]

Thanks for the info!

5x5 Baltic Birch is $66 here. Another supplier has it 4x8 for $119.

[Dave Zellers]

Thicker veneers are less quality??

He's referring to the inside veneers not the faces.

[Cary Falk]

I hate shopping for plywood. I used to get my plywood from HD or Lowes. I was making a cabinet for the kitchen so I decided to get plywood from a real wood place. I paid more for it and it was very bad. It had a lot of voids and it peeled apart by itself. Once cut it would bow and twist. The outside veneer was half as thick as anything at the borg.

[Martin Wasner]

Pretty typical, and it varies unit to unit. Just like veneer quality will vary from sheet to sheet. Sometimes you won't get hardly any, sometimes you rip a sheet and go what the heck guys!

It's unfortunate, but the way it is. Some of it has to do with how the sheets are spec'd out from where they are getting them. There's a lot of options on cores, layups, and tolerance.



I don't know if you have any cabinet shops near you, but I typically keep a fair amount of material in stock, and I'd be happy as a clam to sell you that sheet for $20 less and put another $17 in my pocket. I'm paying about $53 a sheet for white two face birch from Roseburg. I don't use poplar plywood much, but I'd bet it's cheaper yet.

[mark mcfarlane]

FWIW, I bought 3 sheets of paint grade birch in Houston for $37 (each) cash last week. It was $43 n a credit card. It had only a few 1-2mm voids inside. It was actually good enough for stain on ~ 97% of both sides. Best deal I've found so far, from a smallish local supplier to trim carpenters.

My normal dealer quit carrying birch because, they said, the price for the quality they wanted got up to around $100 a sheet. They said something about new tariffs.

[Mike Kreinhop]

I can't find baltic birch plywood anywhere near me, and none of the big box hardware stores sell the metric equivalent of the 4x8 sheet...just smaller sheets. There are a couple of distributors near Mannheim and Heidelberg who will sell full sheets to individuals, but they only stock beech and won't deliver less than 50 sheets. Fortunately, I have a pickup and can haul my own material.

A 4x8 sheet of 3/4-inch (1250x2500x19mm) of beech plywood (called multiplexplatte here) in grade A/B is $119 at today's exchange rate. Without the VAT, the price is $100 a sheet.

[Wayne Cannon]

I get "ApplePly" here. From what I understand, it is the American-made equivalent to Baltic Birch. I've been very happy with it, more than with Baltic Birch -- in fact, I get shop grade ApplePly and find very little wrong with it. It also comes in 4'x8' sheets, instead of Baltic Birch's 5'x5'.

[glenn bradley]

The voids are no problem if you don't need that spot for structure but, if using birch I would just go with Baltic. Unless I need a hardwood veneered plywood like walnut or cherry, I pretty much only buy BB ply anymore. The small premium is worth the better working material. Russian ply or Apple ply have worked well when I'm in a pinch but, I generally just buy 2 or 3 more sheets than I need and build up a small surplus. Of course, you have to watch your grades with any product.

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[Robert Parent]

Doug,

Thanks for the book link...

Robert