Acrylic or polyurethane with Alumilite

[Muggsy1776]

I'm trying to cast paper and I'm getting lots of air bubbles around the edges of the paper. I suspect the pressure pot is pushing out trapped air in the paper. My thought is to seal the paper prior to casting. My question is: spray with a clear acrylic or a polyurethane? I'm using Alumilite slow which is a urethane. Any thoughts?

 

[montmill]

I've used Modge Podge.

 

[dschem]

I use printable waterproof labels and have never had an issue with bubbles, a just straight cast into alumalite. What pressure are you casting at?

 

[duncsuss]

There's a good chance the paper has moisture in it which is reacting with the Alumilite. Try baking it to drive out the water before casting.

Alternatively, switch to an epoxy resin, that doesn't have the same reaction to water as urethane resins.

 

[Todd in PA]

I'll second Modge Podge. I also run a hair dryer on my casting pieces to evaporate off any moisture right before I start mixing.

 

[Muggsy1776]

Thanks everyone. I'm combining scraps of paper along with pieces of a dollar bill. My pressure pot is set at 50 psi. I'll try the hair dryer and the modge podge- I hadn't thought of the moisture.