Forgive my ignorance but this is my first epoxy glassing effort. I’m told it’s not wise to glass inside due to the fumes, but also not wise to glass in temps under 78F (25 C). I have a garage I can get up to prob 70 with a heater, and a greenhouse-like shaping bay I can get to probably the same. Should I just wait until warmer months? Or can i go for it and just expect longer cure times? Anything else I need to know? Thanks
You will be okay at 70* or even a little cooler. You just want to be mindful to use an appropriate hardener for the temperatures you’re working in AND to get your mix accurate and complete. Keeping your blank and resin at room temps for a while before mixing and glassing will lead to more predictable results.
BTW, if this is your first go at epoxy then I recommend changing up your technique a bit because epoxy is a lot less forgiving than polyester resin. You can’t mix epoxy quickly and dump it all in one spot and move it around a lot like you can with poly. You gots to move a lot more slowly and deliberately in both the mix and spreading.
Buy a cheap digital kitchen scale and mix your epoxy by weight. It’ll save you money by reducing your waste when it comes to mixing small batches for repairs and smaller fills. Plus, you won’t have to buy marked measuring cups for one-time use. Also, clean up with vinegar, not acetone. (vinegar is also a lot cheaper than acetone or denatured alcohol).
If you pour each part from a cup instead of the bottle you’ll be able to get your mix accurate right down to the gram. Mix slowly and long (I usually count to 200 strokes) in order to get it completely mixed without adding a bunch of air bubbles.
When you go to pour, pour it out in ribbons like you were pouring syrup over pancakes. “Paint” the flats of the blank from one end to the other so that you won’t have to move any of the resin very far. Don’t pour it all into one puddle and walk it from end-to-end like you can with poly because that will overwork the resin. You want to move deliberately, not quickly. Epoxy doesn’t saturate as quickly as poly.
70 degrees is fine. Just keep it consistent through the process. Fumes are not a big issue, but still always a good idea to wear a respirator. I know guys who glass with Epoxy all the time who don’t use a respirator, but I recommend you use one as an abundance of caution. Occasionally people are allergic. Use nitrile gloves and wear long sleeves. Don’t use Acetone for cleanup. Not recommended with Epoxy. Use throwaway brushes and plastic squeegees. Go slow and deliberate.
Good tips so far.
Keep the chemicals off your skin, gloves go on before containers are openned. A small bottle of 91% isopropyl (rubbing) alcohol and paper towels or some clean rags are nice for cleaning gloves after mixing or any other spills that cannot wait for vinegar or citrus soap. I like to have spares of gloves, squeegees, brushes around in case something tears or falls to the floor.
I have done most of my winter work indoors at 65-70 F 18-20 C with standard surfboard epoxies like Resin Research KK and Greenroom Old #7 ‘original fast’. No issues other than flip times are a little longer than outside in the warm/hot summer. I like to weigh the cut cloth and calculate resin needs from that.
Someone in an old thread mentioned Dr. Foochi’s idea of double or even triple gloves. I suppose if they are not too cumbersome tjat might work. Just peel a pair off when they get too gooey. Then you have on a clean pair when you “boogie down” with AOC.