Thickening Polyester with Silica question

[shep65]

Hi guys I have a question ..How bad did I screw up if I mixed silica and resin before adding the MEKP ? Its been 3 hours and doesn't seem to be hardening like previous batches that were mixed with hardener before mixing in the Silica .

I'm rebuilding a transom and using the thickened resin to glue in my core . I mixed 3 quart cups with Silica but did not add the MEKP until I was ready to use . Hope I didn't just screw up

[Curapa]

I'd put some lamps on it to try to get it to kick. If you mixed it well enough it should kick eventually...

[smokeonthewater]

x2 put heat to it

[phatdaddy]

do not put it in the microwave,

don't ask me how i know

[shep65]

thanks guys !it seems to be hardening up .. I was worried there for a little while .. I read somewhere after I did it to be sure to mix the resin and hardner first because the silica absorbs it and prevents an even cure .

[Curapa]

That's right, but I do know of a few people that pre mix large batches without hardener and take out small batches as needed adding harder after with success.

I do not trust that method, but I have never tried it. I've just read that is not advisable.

[Striper80]

I've mixed the silica in before the hardener without issue, but I noted the measurement before thickening. Then I added the amount of hardener based on that level not the level after thickening.

[cterrebonne]

Originally Posted by Curapa

That's right, but I do know of a few people that pre mix large batches without hardener and take out small batches as needed adding harder after with success.

I do not trust that method, but I have never tried it. I've just read that is not advisable.

I mix the harder first then I add the silica. I do that because I never know when I have time to work on my boat and that resin may go bad before I use it.