Anyone have any cold weather, epoxy glassing expertisetips they can offer me so this all goes smoothly? Everyone seems to just say to wait until it’s warm out, but I know many of you have made the cold weather glassing happen. Let me know what you think.
Cheers,
Zal
When you say “cold”, what are you really talking about? Cold is a relative thing, depending on geography. 50 is cold in Hawaii, but rather pleasant for Maine in March.
Seems I lost the first part of my post… The outside temps right now are around 30-50 deg F, with my basement temp a consistent 45 deg F or so. I am planning to warm the epoxy in a hot water bucket, have the blank warm pre-glassing, and use a space heater in my glassing area. Really just wondering if any other precautions should be made in order to get this done right. Also, I’ll be using RR epoxy with additive F.
If you can get the workspace up to 55, you should be fine. The resin will kick slower, but no major issue. Keep the resin in the warmest room of the house until you’re ready to use it.
You should make a hotbox and do a post cure above 110
Is there a cheap way to make a hotbox? And how long after laminating should i do the post cure?
Thanks,
Zal
What type and density of foam? EPS is not closed cell.
Depending on EPS density,** gas expansion** for air sealed (glassed) in a fixed volume at 50 degrees and then left sitting on a summer day at the beach in the mid to high 80s might be significant.
It’s a PU foam blank, not sure about the density…
If you have an enclosed space and a heater, you should be fine. Epoxy will kick but will take longer and will be more prone to blushing - even ‘non-blushing’ epoxies. Resin Research has an additive that helps in cold temperatures… X-55 accelerator. Heat your resin and turn on that space heater.
The main thing you want to avoid is waiting any significant time period before applying subsequent coats. If any blushing occurs, you will have problems with separation between layers.
I’ve had good results using the ‘Lam-Fill-No Flip’ method as proposed by Benny1 and Leslie at Fatty Fiberglass. As soon as your lamination kicks to the point of being able to apply a tape apron, apply tape and hit the bottom with a fill coat. Let that cure completely before scuffing the overlap areas on both sides with a coarse disc. I run a strip of masking tape/protective paper a few inches in from the edge on the bottom before freelapping the fiberglass on the deck. The entire overlap from the first lamination should be scuffed as well as the area on the bottom that will receive the overlap from the deck.
Same thing with the timing… apply the tape apron and hit it with the fill coat ASAP. You will still have the final overlap remaining without a fill coat. You can either scuff it and apply a fill coat, or just feather it out once it’s fully cured.
Now you have the board laminated and fill coated both sides and you’re good to go. You can wait as long as you want before any subsequent steps but eventually you’ll sand both sides and likely do a finish of some sort. I’ve done polyester gloss coats over coarse sanded epoxy. Lots of guys are use acrylic wipe or spray finishes instead. A final finish coat of epoxy is another way.
In any case, it’s doable. Once the board is finished, put it in your car on a warm (not hot) day. Resin Research and other brands have decent material properties even when cured at room temperatures. The board will be pretty tough even without a ‘real’ post-cure.
Which begs the question…
Why are you using epoxy on a PU blank? You’d save some money with plain old polyester.