Talk Composites - The Forum for Advanced Composites

Sealing oak properly

http://www.talkcomposites.com/Topic34604.aspx

By William Barrie - 1/16/2020 8:24:30 AM

Hi
Every now and again I get the chance of reclaimed oak flooring and like to use glass cast 3 resin on it, my problem is that I have tried to seal the oak with shellac and even MDF sealer but every time I still get bubbles seeping out of the oak! The oak is not old and may have chemicals in it from modern processing i'm guessing which may contribute to the gassing. I have to repair and re-coat at least twice until I get it bubble free. I have noted that you advise a thin coat of resin to seal wood but surely if bubbles get through 2mm of resin then a thin coat wouldn't seal it? The bubbles rise to the top of the resin rather than within the middle of the resin coat if you know what I mean.
Looking for help if anyone has experienced the same.

Thanks.

William.
By Warren (Staff) - 1/17/2020 3:41:43 PM

The sealing coat should solve it as long as you have physical coverage.  Once fully cured, there is no way any typical solvents can out gas and make their way through the physically solid resin. It is possible some resin will soak into the wood enough that you need to do a second sealing coat to get it to actually seal properly.  This is rare though especially with oak and is more likely with rotten or older timbers.