I did a couple test panels using 7.5 oz volan and after brushing on a hot coat the weave still shows through. Has anyone ever had to do two hot coats when using heavy weave volan?
Yes, quite commonly done in the past. Let the first coat gel to the point where the drips crumble like moist cottage cheese. Then shoot the next coat over that. It will bond easily with the first coat.
You could always bast your lam to fill in weave before hot coat with lam resin .
It’s common with heavier, open weave cloth if you don’t load enough resin into the lam. The fact that it’s volan has no bearing on it, as volan is just the finish on the cloth. Are you not used to using 8 oz cloth?
I’ve never used 7.5 volan. I was planning on having 4oz S glass under the 7.5, over 2lb EPS. Hope that’s strong enough. Maybe I should put the 4 oz over the volan to avoid two hot coats? Can you wet out 7.5 + 4 (epoxy) in one pass ? Or would I need to do it in two stages? I actually bought Resin Research SLOW because it’s been so hot recently and because this is my first try at using such a heavy cloth… and I’m doing channels…and a swallow tail. Yeah, I know, what was I thinking???
Why in hell would you do two hot coats? Lam both the 4 oz and 8oz at the same time. Make sure you use enough resin to wet out both layers. If you have to load the cloth a lot then pull off the extra resin, so be it.
I would put the 4 down first, just because 8 oz volan is a little stiffer and takes more work to get it to wrap.
Two hot coats is a waste of time and resin. Once the lam is done, then you do one hot coat, sand, and proceed.
“Yeah, I know, what was I thinking???”
Well heck, what’s the point of doing it yourself if you’re not gonna overcomplicate it even a little?
I just had the same problem with my hotcoat. (over 7.5 Volan) I put the hotcoat on too thin and it didnt entirely fill the weave. I have heard from reputable sources that if using lighter weight cloth + a heavier cloth, its a good idea to put the lighter cloth on top when laminating. The tighter weave will require less hotcoat resin to fill in and your laps wont be as thick. Gotta make sure you work the cloth well to make sure you fully saturate both layers when laminating. I will be doing a squeege coat of lam resin on the cured lamination before hotcoating from now on. Hopefully this will partially fill in the weave and ensure that the hotcoat fully fills in the weave when using heavier cloth.
What? You’ll be fine, 2 pound EPS acts more resiliant than standard PU density foam. Good call on the slow hardner, particularly since it’s hot. Laminating, one pass. Just mix plenty of resin (5 oz/foot of board length for this glassing schedule on the deck, IMO) and dump it onto the deck immediately. Let it settle into the cloth on its own, helping where the bubbles form. 7.5 oz volan on the bottom? Pretty overkill, but use same technique and wet out the channels really well and get the cloth to snug-up in the channels. I’d probaly mix 4 oz/foot of board length for the bottom. 3…2…1… calling the epoxy minimalists who use 0.75 oz for an entire board.
Take your time and have fun with it. Enjoy the journey. The best part is after you’ve cut all the cloth laid it out perfectly and then you mix the resin, you gotta go forward.