Is This Mineral Streaking Acceptable for A1 Maple Plywood?

[Chris Fiore]

Hi,


I just purchased the wood for my first big woodworking project, a large computer desk. For the base material of the cabinets and table top I am using A1 Grade Maple Plywood which I purchased at my local lumber yard. One of the two sheets is free from any defects in the face veneer. Unfortunately the piece which they cut for my table top seems to have a fair amount of what I think is mineral streaking, which I didn't notice until I brought it home. Based on the grading system it says that "slight mineral streaking" is permissible for grade A1 plywood. I have no expertise here so any qualitative measurement is difficult for me to interpret. Does the provided pictures look like "slight mineral streaking" or more excessive. I'm referring to the dark brown/black streak which run parallel with the grain. There is dirt in the picture which I was able to remove with light sanding. This stuff cost $99 per 4'x8' sheet, so I want to make sure I'm not getting hosed.

http://img.photobucket.com/albums/v245/lilmanmgf/40302aa1-3e9c-4276-b4bc-5758517cea21.jpg
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_172921.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_172900.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_172820.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_172814.jpg


http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_171403.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160804_171333.jpg

[Andrew Pitonyak]

No picture is attached....

Sorry, nothing else to add since I have no idea about grading and mineral streaks.

http://atlanticplywood.com/img/media/plywood_guide_wlumber.pdf

The above document states:

"An A face may allow slight mineral streak and/or vine marks."

[J.R. Rutter]

That is a bit much for an A face, IMHO. If that showed up at my shop, I would be asking for a credit for regrade down to shop grade and cutting around it.

[Mel Fulks]

Must be that you did not read the brochure...." The beautiful black streaks are a natural phenomenon that assure it is
GENUINE maple". yep,the contact paper doesn't have it. I like J.R.'s idea.

[Chris Padilla]

It happens and is a part of maple. Usually, I find one side a lot cleaner than the other but you could just spend time sorting the plywood before you buy it. That might be painful but if you want a perfectly clean face, it might be the only way or find a different supplier or make sure you communicate your desires to the dealer.

I bought similar looking maple plywood from Home Depot for $50 but I am planing to stain it a darker color so the mineral streaks didn't bother me as much.

[J.R. Rutter]

I don't think that the smaller streaks are a problem, but when they get wider than 1/8-1/4" and longer than 2-3" then we defect them out.

[Ellen Benkin]

I had similar problems with a shipment of maple plywood and I rejected it and found a better supplier who could give me sheets that were clear on one side. I could have had sheets clear on both sides for a higher cost. I do think some of the smaller streaks add to the character of the wood but I would not accept sheets with wider or longer streaks.

[Jamie Buxton]

On A-1 plywood, the front face (the A spec) is higher-grade veneer than the back face (the 1 spec). Where I buy plywood, the A face is not rotary cut, but rotary cutting is permissible on the back face. Your pics look like the veneer is rotary cut. Are your pics from both faces, or just from one?

[Chris Fiore]

On A-1 plywood, the front face (the A spec) is higher-grade veneer than the back face (the 1 spec). Where I buy plywood, the A face is not rotary cut, but rotary cutting is permissible on the back face. Your pics look like the veneer is rotary cut. Are your pics from both faces, or just from one?

I don't know that the other side looks much better:
Side A:
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205144.jpg


http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205152.jpg


http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205157.jpg

This is what I assumed is the rear side:
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205334.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205339.jpg

http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205345.jpg

Is that correct?

On the second sheet both sides appear to be continuous rotary cuts. Murphy is the manufacturer. Do they just have lower standards?
Front:
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205621.jpg


Back:
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205604.jpg


Marking:
http://img.photobucket.com/albums/v245/lilmanmgf/IMG_20160805_205846.jpg

[jim mills]

Jamie's description is spot on. The "A" side should be flat sawn. Typically about 12" wide veneers. the "1" side is typically wider rotary cut veneers up to about 24" wide with some mineral streaking. The A1 ply I have been getting is "combi-core" which uses mdf as the first layer of core directly below the veneer on both sides. Makes for a much flatter surface. Look at your plywood under a raking light. Downside is its HEAVY. Your plywood is typical of about 1 in ten sheets that I get. With volume, it's easy to cut around, or use for backs, bottoms, etc. When dealing with a couple sheets for a small project, it can be discouraging. Just luck of the draw. If I need something unusual, like a couple sheets of walnut ply or something, I will typically go get it my self, so I can hand pick it.

[Gerry Grzadzinski]

From my experience, if you buy plain sliced, or flat sawn plywood, it cut the same on both sides. Same with rotary.
You can get A1 rotary cut plywood, which is what the OP appears to have.

Here's a brochure from that manufacturer which states that their maple plywood is rotary cut.
http://www.detroitforest.com/wp-content/uploads/2012/10/murphy.pdf

[glenn bradley]

Since they cut it for you I would just accept the lesson, use the material for something else and go get a usable piece. Small natural color variances in maple and cherry (or any wood for that matter) attest to the natural nature of the material. How much you are comfortable with is up to you. I push the limit sometimes:

342056

I would have left that piece behind but, you can certainly use it for something else or a paint-grade project down the road. On the other hand consider how the desk will be used. Most of my desk is covered with computer, keyboard, printer, paperwork . . . maybe it won't even be noticed by the casual observer (it would bug me every time I sat down though but, that's me).

[J.R. Rutter]

Murphy is the manufacturer. Do they just have lower standards?

IME, a bit lower, yes.