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Forum topic by MrRon posted 12-06-2017 07:02 PM 546 views 0 times favorited 11 replies Add to Favorites Watch
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MrRon

4492 posts in 3080 days


12-06-2017 07:02 PM

I recently came across some 3/4” DF plywood, grade A/C that was in my shop. It has to be at least 50 years old. It is 7 ply and a full 3/4” thick. The plywood is remarkably sound with no warping or delamination. Compared to what you can buy today, it is still usable in any project requiring quality plywood. The piece I have is 18” x 96”. I hate to use it for anything unless it is for a serious project.


11 replies so far

View DS's profile

DS

2822 posts in 2257 days


#1 posted 12-06-2017 07:10 PM

Mr. Ron,
as someone who buys lots and lots of plywood on a daily basis, I might suggest that the difference isn’t today vs. 50 years ago. It’s more that domestic plywood uses imperical dimensions and imported plywoods use metric dimensions. 18mm and 19mm ply is thinner than 3/4”.

Since the most economic subtrates (cores) are imported and that is mostly what ends up on big box lumber racks in order to compete on price, I can see how your perception is what it is.

Rest assured, if you are buying from USA mills, plywood is still being sold in a full 3/4” thickness.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

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MrRon

4492 posts in 3080 days


#2 posted 12-06-2017 08:10 PM


Rest assured, if you are buying from USA mills, plywood is still being sold in a full 3/4” thickness.

- DS


I haven’t seen any USA made plywood recently. Where would I buy it in retail quantity?

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William Shelley

477 posts in 1305 days


#3 posted 12-06-2017 08:42 PM

You can still buy good plywood now. It’s just not usually sold at home depot / lowe’s. I don’t understand the point of this thread.

Construction grade ply is always 1/32nd undersized.

EDIT:

Also, usa made vs import has nothing to do with thickness. Foreign mills can still produce imperial dimensions. Just like domestic mills can also produce metric dimensions if they wanted.

-- Woodworking from an engineer's perspective

View DS's profile

DS

2822 posts in 2257 days


#4 posted 12-06-2017 08:52 PM

I rarely buy retail.
Mostly, wholesale Hardwood Lumber suppliers will carry a good stock of USA made plywoods.
Brands like Roseburg, Colulmbia Forest Products, States Industries and Boise Cascade to name a few.

Some sell in retail outlets and others don’t. Expect to pay a little more money as the imports are usually subsidized by foreign interests trying to maneuver themselves into US markets.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

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DS

2822 posts in 2257 days


#5 posted 12-06-2017 09:10 PM

There are a couple of overseas core plants that are producing cheap cores in massive quantities. Some USA companies are bringing in these cores and putting domestic veneers on them and calling them domestic plywood. These VC plywoods are ALWAYS under thickness by a lot.

For hardwood plywood, the core, even domestic cores, are made to receive domestic veneers which are typically thicker than the import veneers. So, even a domestic core with an imported veneer will be slightly undersized, but not to any significant degree.

To normalize for the various different thicknesses from our vendors, we adjusted our construction methods (we are a high-end cabinet and furniture mfg) to largely nullify the joinery effects on the final product. (Loose vs. tight dadoes, etc)

We also established solid distribution lines for our main products and they are known quantities for us.
Certain products, such as the more exotic veneers, will ONLY be imported veneers, (where else can you get Macassar Ebony?) but, we can order it on substrates that are compensated for thickness. (MDF core and Classic Core come to mind.)

Also, all MDO cores I’ve ever seen are also domestically produced and take veneers well, but are full thickness BEFORE any top treatment, so if you laminate veneers on them, you will be over-thickness which can also be problematic.

Bottom line: Educate yourself. Ask questions. Most likely you are going to encounter foreign plywood in the retail big box, but not always. Most USA made plywoods are edge stamped with grading and core information and can tell you a lot more than what the SKU tag will have to say.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View ScottM's profile

ScottM

565 posts in 1983 days


#6 posted 12-07-2017 04:06 PM

The local HD sells Colulmbia Forest Products plywood. It’s still pretty much crap. Lots of voids, very thin veneer, and most warps like crazy after cutting it.

View DS's profile

DS

2822 posts in 2257 days


#7 posted 12-07-2017 04:24 PM

Most VC plywoods we buy come in between 0.743” and 0.750” thickness

A mill-select shop ply (fancy words for “we don’t really care what it is as long as it’s cheap”), comes in at about 0.710”, but, can actually be just about anything they want to get rid of today. (We received a few Quarter-Sawn highly-figured Black Walnut sheets once as mill-select throw away sheets. They got set aside)

As for crap plywood, a lot has to do with the specs on the core. How many plies?, are voids allowed? Is the adhesive water resistant? these are all grading questions about the core. Some cheap cores don’t even support their own weight. More plies generally means more sturdy and more stable.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View ArtMann's profile

ArtMann

686 posts in 652 days


#8 posted 12-07-2017 04:45 PM

I was buying plywood 40 years ago and I am still buying it today. It is possible to buy the same quality today as I bought then but the normal stock that is carried at big box stores and many lumber yards is much lower in quality than it was then.

View MrRon's profile

MrRon

4492 posts in 3080 days


#9 posted 12-07-2017 11:36 PM

When I want good quality plywood, I usually have to go with Baltic birch, but I am limited to 5’ x 5’ sheets. Thickness is not a problem; I can always compensate for that. In general, plywood is a hit or miss situation. Every project has to be tailored to the plywood available. Even plywood from the same mill can vary in thickness to make a difference. I find projects take longer to do due to the variations in plywood thickness that affect dado’s, rabbets.

View Dark_Lightning's profile

Dark_Lightning

2916 posts in 2945 days


#10 posted 12-12-2017 03:37 AM

MrRon, I can appreciate what you have in that piece of plywood. One doesn’t see much like that these days, especially at the BORGs. When I worked for Lockheed Advanced Development Division (AKA Skunk Works) we used to get Baltic Birch in sheets that were 5’ X 10’, for model making. I don’t know if anyone sells it nowadays; I’ve not seen it at the yards I go to. I have seen 4’ X 8’ plywood that is claimed to be equivalent quality, but haven’t looked at it closely. I’m looking to build a tool storage/work area; once I get the design set, I’ll look at the 4’ X 8’ stuff. On second thought, Ima trawl the store first. They claim it is the same, whether it is 4’ X 8’ or 5’ X 5’, but I’ll have to lay my own eyes on it to be sure.

-- Random Orbital Nailer

View Carloz's profile

Carloz

971 posts in 428 days


#11 posted 12-12-2017 01:35 PM



I recently came across some 3/4” DF plywood, grade A/C that was in my shop. It has to be at least 50 years old. It is 7 ply and a full 3/4” thick. The plywood is remarkably sound with no warping or delamination. Compared to what you can buy today, it is still usable in any project requiring quality plywood. The piece I have is 18” x 96”. I hate to use it for anything unless it is for a serious project.

- MrRon


Dont be a scrooge and buy quality materials .

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