Latest Discussions : Tools & Workshop


06:12PM | 05/15/05
Member Since: 08/14/01
6 lifetime posts
I am building a stereo speaker cabinet and have some questions about birch plywood.

1.) Is marine plywood much heavier than non marine plywood for a give size (3/4", 1/2",etc)?

2.) Is marine plywood much stronger than non marine? So could 1/2" marine have the same strength as 3/4" non marine?

3.) Most of the people I have spoken to use birch for the speaker cabinets. Many of them say to use 13 ply baltic birch. All I can find localy is 7 ply birch.

A.) Do I really need 13 ply or is 7 strong enough?

b.) If I use the marine will that not add strength so I can use 7 ply?

c.) What is the difference between baltic and other birch?

4.) Can you think of a reason other than looks people use the Birch?

I am hoping someone here can help with some of the answers as most people at the stores have no clue about the woods that are there.



07:00AM | 05/18/05
Member Since: 02/20/04
52 lifetime posts
Most regular Birch plywood is as you said 7 ply, but generally the interior plys are not birch but some other soft wood with just the outside layer being birch. As I recall Marine grade plywood is just manufactured with a mairne grade glue so that it won't delaminate when it gets wet. I am also thinking that it is 9 ply with all layers being birch. It has been many years since I have used any marine grade plywood so please don't hold me to this. Other than the number of layers in the baltic birch it is also birch all they through. and I believe that the Birch that comes from the northern lattitudes where this comes from is supposed to be a denser wood and there for harder. When making drawers I prefer to use this type of plywood also. Just remember that 3/4, 1/2 etc thick plywood is no longer 3/4, 1/2 or whatever but actually 1/32 under size.. It's kind of a pain when building cabinets that you want to be an exact size but you get used to it.

Hope this info helps.


07:46PM | 05/29/05
Member Since: 05/28/05
1 lifetime posts
I've been using Finnish Birch (marine plywood.) the marine grade plywood has no voids and is top quality birch in all layers. Baltic Birch plywood is a lesser grade and sometimes will contain some voids in the inner layers of birch. Baltic Birch however is much cheaper and easier to find unless living on the East coast.


08:42AM | 07/10/05
Member Since: 07/05/05
2 lifetime posts
How much weight can 3/4 birch plywood support and across what distance? I'm building a stand-alone custom cabinet unit to house a wine refrigerator and it will be 64" long and 27" deep with a plywood top. My original plan was to build support legs 22" in from each end, but I'm not sure if those legs are necessary now. I will reinforce the countertop with a 1x2 frame and it won't have anything other than magazines, a couple small appliances and my keys on top of it. Can the plywood and 1x2 frame handle the 64" distance? Any formula for this weight rating?

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