Hot Coat While Curing?

General Discussion
1

This might sound stupid but I was wondering if there is any advantage in hot coating right after cutting the laps or at that same curing point while doing a free lap. I saw in a fiberglass hawaii surfboard repair video where the host did a hot coat and when it was about halfway cured did another one. I was wondering if using my suggestion would help in the “chemical bond” instead of a “mechanical bond”? Your Thoughts?

2

adam,

 what type of resin are you talking about??? polyester or epoxy??? I try to always filler coat  with epoxy or “hot coat” as you say, justy past tacky of the lamination. For practicle and convenience reasons. If you are thinking chemical and mechanical bond reasons you may be over thinking things a bit.

3

I think it is safer to wait for your lam to be fully cured. The reason is that you may need to sand down any wobbles or hard fiberglass edges before you hotcoat, just so you have less work when it comes to sanding your board.

I don’t know of any difference concerning the bound if you don’t wait for your lam to be fully cured, and even if there is a chemical difference I am not sure it would be noticable enough to really make a difference.

Regarding the Fiberglass hawaii video, are you sure the first batch was hotcoat and not just lam resin (like a cheater coat)?

If the first batch was hotcoat, I assume that the wax that rised on top of the first hotcoat should be removed (sanded) before applying any other hotcoat/gloss coat.

That said, this is just an assumption and I don’t know what the result would be if you don’t sand between the layers.

J

4

If you are talking about doing the hotcoat right after the lam gels up, that’s not unusual and there’s no reason not to. The exception being when the lam is funky and needs a bit of grinding to clean it up. Experienced laminators can get away with it just about every time. Get your glassing technique down, and you can hotcoat right away. Saves time, makes a better bond, IMO.

 

5

I meant polyester resin

6

For some reason I didnt think about sanding the lamination. Yes, in the fiberglass Hawaii video it was just laminating resin then sanding. 

7

Thats what I thought

8

All of the above, is true.      It is a technique that was common in the Balsa era, when lam, hotcoat, and gloss,  were all done with one resin.     Richold finishing resin.    I did not use lam resin until 1960.