What's this buildup?

paczowski123 · Dec 31, 2015

So I did a bit of glass reinforcing on my ski, and it's been sitting about a month and a half and today I walked out and noticed this brown splotchy buildup on the glass. It almost looks like rust? Anyone seen this before? It wipes off mostly, but I wasn't sure what it was?

BTW I know it's not the best layup and there are air bubbles on the top layer.the other two below it went on pretty good, though.

ajmps1 · Dec 31, 2015

Do you use that yellow rust inhibitor spray stuff? Aside from that, is the resin cured? What did you use? Home Depot poly or good epoxy. Did you weigh and mix thoroughly or just eyeball the mix ratio?

paczowski123 · Dec 31, 2015

No, haven't used that. Resin has been cured for quite some time, work is about 1.5 months old. Epoxy resin was US Composites mixed 4:1 as directed.

ajmps1 · Dec 31, 2015

If its just been sitting there un used anf this is the first youve noticed it id say its the resin not properly cured. Maybe you could brush a hot coat on? Someone else jump in here.

paczowski123 · Dec 31, 2015

Well, it's strange, it's been done for quite a while, and this just recently showed up. I would think if the resin wasn't cured properly this would have showed sooner.

paczowski123 · Jan 8, 2016

Well, just as an update US Composites responded to me. He claimed it was called "blush" and is completely normal and common in 4:1 resin and even sometimes 3:1 resins. Nothing wrong or to worry about, just wipe it away.

Fro Diesel · Jan 8, 2016

I switched to trinity t3 for my reinforcement years ago. the fit and finish for wet layups in the garage turns out much better. I also put a heater in when curing to try n keep the room 70-75

paczowski123 · Jan 8, 2016

Yeah, it seems this blushing is generally due to faster hardening resins, also from moisture in the air. Which is hard to stay away from in GA

What's this buildup?

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