Talk Composites - The Forum for Advanced Composites

Remove white on parts after water reaction. ?

http://www.talkcomposites.com/Topic23881.aspx

By Interloper393 - 9/11/2017 5:30:53 PM

Hey.
When any of the xcr resin comes in contact with water it goes white.. 
Even after 3 or 4 days to cure..
Sanding removes it but it goes into the weave and is visable after another coat of resin,  some.does go away but alot of it dosnt.any suggestions? 

If you dry sand how are you to clean the part after? 

Cheers 
By Warren (Staff) - 9/12/2017 8:21:51 AM

Typically it only goes white when not fully cured as uncured epoxy is hydroscopic.  Maybe you need more time and a warm place to fully harden the resin.  Also if your mix ratio is slightly out, the resin can seem hard but remain vulnerable to moisture absorption due to the incorrect balance of hardener and epoxy leaving uncured material in the hard resin mix.

Get the parts somewhere nice and warm to help drive out as much moisture as possible.