Talk Composites - The Forum for Advanced Composites

milky laminating epoxy?

http://www.talkcomposites.com/Topic2685.aspx

By odo - 8/25/2012 2:28:38 PM

hi guys,

i tried to skin a plastic piece about 1sq meter. i used carbon base coat, then diolen and after that layer of  carbon fibre laminating epoxy resin. i applied laminating epoxy with plastic card. so far so good. after 48 hours i tried to apply second layer (same technique) but after 5 minutes of flattening with card the epoxy started to be white/milky (i guess because of micro air bubles). 
the result is that diolen is not visible because second layer is milky. 
the rest of epoxy i didn't use is on picture (surplus epoxy from board i put back to mixing pot). 
next day the surplus epoxy in mixing pot hasn't flat surface and had bilions microair bubles.

i am sure i did something wrong but don't know what... at the begining the epoxy had some air bubles (only few as usual) but when i started a work with plastic card it became to have more and more air bubles and result was the whole epoxy was white.
do you have any similar experience pls? 

your help is more than appreciated
ondrej

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By benet - 9/19/2012 8:49:57 PM

I would like to know exactly what the plastic card was, i once used a piece of plastic cut from an ice cream tub to smooth out epoxy, i smoothed really well but something made micro bubbles appear on that job (not as badly as in your pot !!) and the only thing i thought i had done differently was to use the soft plastic spreader. ? !. I dont use it anymore, i think you have to very careful when adding anything particuly other untried plastics to a resin curing environment.