Author Topic: Plywood test  (Read 2443 times)

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jadranko

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Plywood test
« on: February 26, 2010, 05:10:28 AM »
If u cant find marine plywood or it is too expensive (in my area is around 85$ per square meter, so it is around 255$ for standard sheet, 122x244 cm) buy one sheet and test it like this (I found it on boatdesigns.net) :

1-Buy a sheet and count the number of inner plies 7 for an 1/2" and quality and thickness 1/20" mini of the outside plies (knots, discoloration, splits etc...)
1-line glues must be dark brown (phenol)
2-cut the plywood in squares of 4*4 inches and look for voids and other defects.
3-with a chisel try to separate the plies: the glue lines must be stronger than the wood itself.
4-take ten squares and boil them 1 hour. Delamination while boiling is forbidden.
5-Destroy one boiled square with a chisel trying to separate the plies: the glue lines must be stronger than the wood itself at least at 80%.
6-take 2 squares and make it dry totally in a oven at 120 celsius degrees. Delamination while drying is forbidden.
7-Destroy one dried square with a chisel trying to separate the plies: the glue lines must be stronger than the wood itself at least at 70%.
8-meantime reboil one hour more the remaining 7 squares.
9-Destroy one re-boiled square with a chisel trying to separate the plies: the glue lines must be stronger than the wood itself at least at 70%.
10-take 2 re-boiled squares and make it dry totally in a oven at 120 celsius degrees. Delamination while drying is forbidden.
11-Destroy one re-boiled and dried square with a chisel trying to separate the plies: the glue lines must be stronger than the wood itself at least at 60 to 70%.
12-Clean the kitchen and buy flowers for you wife. Don't forget to open the windows because of the smell."....

Brian.Dixon

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Re: Plywood test
« Reply #1 on: February 28, 2010, 05:03:12 PM »

I've heard of some people boiling and then freezing the still-wet wood and then re-boiling to see if the expanding ice in the wood causes it to delaminate.  Interesting.

Brian