Plywood Quality Issues

An in-depth discussion of quality concerns regarding hardwood plywood, with details on the way various plywood flavors are put together. December 30, 2005

A contractor ordered 4 pieces of 1/4" VG fir plywood from us. Each piece was to be 4' wide by 2' long. The dimensions weren't critical, so we ordered one sheet of plywood from our supplier, cut the pieces, sanded, and off they went to the finisher. The first sheet we got had veneer leaves 4" wide and was striped and cheap-looking. The second sheet had blue stripes peeking through the face veneer, perpendicular to the grain direction, where the veneer was nearly sanded through.

We tried before, for the sake of economy and expediency, to use off-the-shelf plywood for exposed faces. We had to remake half the faces on one set of built-ins because of sand-throughs due to irregular substrates. We now have a policy of only using custom laid up sheet goods for clear finish. However, there are times where the look of the veneer is not critical, time is of the essence, and off the shelf plywood should be fine. But the quality of the plywood seems to be getting so bad that this is no longer feasible. The primary culprits are irregular substrates (even Armor Core) that lead to burn-throughs, and aggressive finish sanding by the manufacturers so the veneer is paper-thin.

Do you experience the same frustration, and if so, what do you do about it? Also, is anyone aware of a supplier of plywood that is a premium grade? The company we order our custom panels from has no problem giving us a high quality product, and I believe they are dealing with the same thickness of veneer as the big manufacturers. I would gladly pay a bit more for usable plywood.

Forum Responses
(Cabinetmaking Forum)
From contributor A:
If possible, try to buy the VG Fir on MDF core. This will eliminate problems with the substrate such as telegraphing. If the veneers are poor quality or sanded through when the sheet goods are delivered, refuse them and change suppliers.

From the original questioner:
In this circumstance, MDF was not a good option - the panels are going in a bathroom somewhere, so the contractor felt better about a plywood core. I'm trying to find the best supplier for each material, and we are looking into changing suppliers, but we have already changed primary plywood suppliers once. And we source from five or so different vendors depending on what we need. Refusing materials is a big problem. I don't want to be scrutinizing every sheet as it comes off the truck, nor do I want my clients to have to scrutinize my products to see if they are good quality. I want a predictable product delivered to my doorstep.

From contributor A:

Yes, scrutinizing and rejecting raw woodworking materials is a big problem. I have an easier time with that since I am a one man operation. I generally go the loading dock on a will call basis and make sure my veneered sheet goods have sequenced veneers. If you are high volume I am sure my approach is impractical. But, I think if you refuse substandard material from a supplier a few times, he will probably start taking more time selecting items to ship to you.

From contributor B:
I've given up on a lot of the suppliers for the same reasons you state. I now use Edensaw for just about everything. I've found their sheet materials to be consistently good and on the rare occasion that a sheet isn't up to snuff they will hand pick a new one and trade it out without a question. I order MDF core, especially with CVG fir.
I can take a day and get to their warehouse from Bellingham with a nice, scenic drive and ferry ride, pick through their exotic hardwood, and drive back with a bunch of very tasty 8/4 bubinga, walnut, and/or cherry for my next project - or it will be on their next truck.

From the original questioner:
To contributor B: Thanks for your input on Edensaw. We haven't used them as much for panel products, but that will likely change. They also seem to be the most on top of FSC certification, green products, etc.

From contributor B:
Yes, and that's also another good selling point in this neck of the woods. On reading your original post again, I definitely agree with you. I don't balk at all paying a bit more for a superior product. I wish I could spec the top veneer thickness. I fail to understand exactly how much more profit a sheet goods manufacturer reaps from using see-through tissue thin top veneer. Granted, their materials costs might go down a bit, but what price can you put on your reputation?

I usually order WPF when the appearance is critical. I've also found that the awful appearing zebra stripe effect you get in CVG fir when the leaves are too thin actually seems to diminish in the finished product. I think it's a combination of looking at a smaller area on a box side, and the finish itself seems to even things out a bit.

From contributor C:
I had the same problem with cross-grain stripes visible under fir plywood. It seems to me, and it was more or less confirmed by the salesman, that the problem is inferior plies used as crossbanding, i.e. tropical hardwood (virola?) with dark streaks running through. The thickness of the face appeared to be the same as ever. Unfortunately in my area VG doug fir is only available on veneer core. I was veneering my own doors but relying on sheet goods for the cases, in some areas including visible exteriors.

From contributor D:
Ply Core has a reputation for telegraphing of core through veneer and those blue/black lines reading through because of thin veneer. We use MDF for exterior faces wherever possible. Since your contractor must have Ply Core, how about using Ply Core with the outer core layer made of particle?

From contributor B:
Actually my abovementioned MDF Core plywood is actually what Edensaw calls Classic Core. It's kind of a combination deal - the main core is ply layers with a thin layer of MDF just beneath the top veneer. It's the best of both worlds - the MDF gives a dead flat surface for the top veneer to lay on and the inner ply layup reduces the overall sheet weight and increases the screw holding power in the edge.

From contributor F:
Armor Core is the same material as Classic Core but without the veneer laid up on it. Classic Core is laid up on Armor Core.

From the original questioner:
I'm telling you, the Armor Core, or Classic Core, is not as flat as MDF. Our project with the burn-throughs was the result of substrate defects and anomalies in Armor Core. I was as surprised as my vendor was, but I don't think you can rely on this core being as flat and defect free as MDF or particle board.

From contributor F:
To set the record straight I'm the owner of Edensaw Woods. For an off the shelf product, we as distributors have very little choice in the veneer. With VG fir we have a choice of bookmatched and slip matched. Edensaw purchases slip matched as this reduces the zebra look of the faces when using bookmatched. Thickness of faces is not an option and to make matters worse it was recently announced that these would be moving to 1/48th which will increase all our problems.

Width of components is not an option and the minimum width allowed is 3". We have core options and stock hardwood cross band veneer core and Jaycore IV. Jaycore IV is a type of Classic Core that is a calibrated veneer core with thin MDF crossband under the face veneer. Classic Core II uses a thicker MDF crossband and Classic Core I uses Particleboard crossbands. Jaycore IV is the Cadillac of these cores and is a lot less weight than a full-on MDF core panel. For those who just will not accept particleboard or MDF in their panels we have the Veneer Core that utilizes a Hardwood Crossband in place of the MDF and Particleboard.

Edensaw stocks Columbia FSC only if available. We also stock only panels using the new Purebond No Added Formaldehyde glue on panels that are appropriate. For instance we not use Purebond on 100% MDF core as the product already has formaldehyde, but we do use it on all our Jaycore Panels and Veneercore panels.