How long does plywood need to dry before using?

[67-LS1]

I’m definitely using epoxy. The West System seems to be the simplest and most thorough system for a newbie like me.
I'm also going to fair everything out to make sure I don’t have even a pinhole.

 

[wet feet]

Class rule requires 12% moisture content before gluing. Builders claim 15% will do. Wood moisture meter are relatively cheap nowadays. From 10 to $15 on line.

Test conducted showed that epoxy has a higher penetration in wood than polyester. This appeared in PB article a long time ago. It is because epoxy is a "glue" while poly is not, To use poly as an encapsulation material for wood, a "mechanical bond" is needed. This is done by driving small nails in the wood with head partially protruding or partially sunk staplers, then a layer of mat with poly. VE is better than poly so, finish off with a layer of VE.

I've never had too much faith in moisture meters.They work well in the zone between the probes,but I have grave doubts about the moisture content of anything being absolutely uniform throughout.Immediately after coming out of a kiln is probably the best time to get a good result.My own experience of sheet materials includes MDF left in a cold and humid boatyard shed.It swelled in thickness about 8% at the edges of the board and moisture was the cause and yet the middle of the sheet,which was covered by the rest of the stack retained it's original thickness.Which illustrates that exposed surfaces are likely to contain more moisture.so where do you apply the probe to get a realistic reading?I do know of a few workshops where a daily record of humidity is maintained and it is a handy record to have.

A more reliable method is to weigh a sample,and good digital scales are not only cheap but they are virtually essential for mixing some formulations, and then heating it in a well controlled oven to about 105-110 deg C to remove all moisture.When the weight has stopped going down you weigh it again and do the calculation.It can be really easy if your small oven has a modern digital controller.The result is beyond doubt.

 

[rxcomposite]

I've never had too much faith in moisture meters.

Have faith. Wood takes a long time to dry. About a year or use of temperature controlled kiln. It is the innermost fiber that takes a long time to dry. Once it dries, the reverse takes place. It is the outermost fibers that quickly takes in moisture while the innermost remains dry. I suppose when the manufacturer bonded the veneers, the wood is dry in accordance with the specs.

According to the instruction manual, only the surface and edge can be measured nu the meter. I guess to measure inside humidity, you have to prick it.