drying the core and moisture

[mikic1]

Hello all,

1. I am about to press my first board very soon, wooden core, and as I know that moisture fumes can in certain cases build up quite a lot of pressure, I was speculating if trapped moisture in the wood core could at some point build up enough pressure to create de-lamination issues or similar? Any good reason to keep to wooden cores nice and dry before layup, how do you store your cores?

2. Regarding my first pressing: I will be using supersap CPM epoxy with potlife of 50min. Is it better to build up pressure and heat once the epoxy goes to the gel state in order not to squeeze out too much of the epoxy? I am sure there is a topic on this somewhere, just have not found it yet.

Cheers!

[vinman]

I tend to apply pressure for 10 min before turning my heat on. I do this to prevent the epoxy from kicking before things get flattened out from the pressure.

As long as your epoxy is not kicking in the pot you've probably got plenty of time for this. I've done 6 pair this way with no issues. And I think it gives me a flatter base.

Be sure to make your epoxy in small batches in a large container. Big batches
In a small container will kick early and get you in trouble.

I make 4 separate batches of epoxy each weighing 200g total and find this volume does not kick to fast in a quart sized container. So for supersap CPM
This would be 133g resin and 67g hardener.

[mikic1]

Thanks for the very useful tips!

[twizzstyle]

I would not wait for the epoxy to gel before applying pressure/heat. If you are worried about too much squeeze out, just press at a lower pressure.

People on here press from anywhere from 14psi (vacuum bagging) up to 80+ psi. So it all depends on what your results will be. For your first time, you're just going to have to pick something and try it and see what you get, then adjust as necessary for future builds.