Plywood Grading Rules :Part 13 Soft Plywood Grades
|Softwood Plywood Grades|
|In years past, it was easy to find cabinet quality softwood plywood at just about any lumberyard or home improvement center. But not anymore. Today, with the high cost of lumber, all they usually stock are construction grades. To find a higher grade, you’ll need to do a little legwork.
GRADES. But before you do, it’s a good idea to be familiar with softwood plywood grades. The most common are A, B, C, and D. With the A and B grades, large knots are replaced with football-shaped patches. Small knots and slight gaps are filled with a synthetic wood filler, and voids along the edges are common.
In the lower grades of plywood (C and D), there’s more patching and filling — even open gaps and defects are allowed. For shop use, we’ll generally stick with a BC (utility) grade of plywood (around $25 for a 3/4″ thick sheet). But if we’re building a piece of furniture, we move up to a higher quality plywood.
HIGHER QUALITY. Here in Des Moines, Iowa, we can buy quality, high-grade AA and AB softwood plywood from a national lumber dealer — one with with stores all over the US — and from a local lumberyard that caters to the professional cabinet shops in the area.
If you have trouble finding dealers like these, try looking in the Yellow Pages under cabinets and cabinetmakers, or millwork shops. Then give them a call and ask where they’re buying their softwood plywood.
FACE VENEER. When you do find some, take a close look at it. We’ve noticed that there’s a wide range in quality — even within a grade. For example, at one local lumberyard, we can buy two 3/4″-thick sheets of AB plywood that are both produced by the same manufacturer. One sheet has five plies with wild grain on the “A” face ($45). Knots have been removed and patched. Other surface imperfections have been filled. And since interior plies are a lower grade, there’s a good chance the sheet will be riddled with voids.
The other sheet is a different product manufactured to a higher standard ($48). Instead of five plies, there are seven. The grain and color on the “A” face is straighter and clearer. There are no knots or patches. And with higher quality interior plies, the sheet is free of voids.
It’s our experience that even though you’ll have to pay a few dollars more for this type of softwood plywood (and do some extra legwork to find it), it’s well worth it.
Special thanks to the original source : http://woodworkingtips.com/etips/etip05.html .