most of the boards i have been glassing have been epoxy, i have gotten a couple of US Blanks to shape. my question is, is it ok to lam, and hot coat the boards with Epoxy Resin, and if i decide to gloss the board, then can i use PU gloss?? Or should i use Pu resin from start to finish.
And or either is fine.
PU is a type of foam so you won’t be glossing anything with that - what you’re referring to is called Polyester resin. If you decide to use PE over epoxy you need to sand the epoxy so it’s rough and then wipe it down with de-natured alcohol or it won’t make a bond. The ammount of sanding you’d need to do for the gloss coat, etc you’re much better off just doing the lam in epoxy and the rest in PE. Personally I’m not a fan of epoxy because it’s expensive and a pain in the ass to work with sometimes (takes forever to cure) so I vote do the whole thing in PE but that’s up to you
the only resin i have at this time is Epoxy, but i agree about the work of eps foam. Lots of extra steps to do. I need to use up the epoxy resin, but it’s still ok to use it on PU blanks? i had an old clark foam blank i bought of a guy for 20 bucks… the lam coat went well, but when i did the fill coat, it looked like someone had pissed bright orange/yellow splotches along the rails. I couldnt figure that one out. i will try to post some pics of that on here soon. But if i gloss a board with poly resin over epoxy resin hot coat, i need a mechanical bond. what do you think, just sand it real good with 80 or 100 grit??
If you do the "Lam" in epoxy you must do the "Hot Coat" aka "fill coat" with epoxy..........
Polyester glassers are happy to give out wrong advise...happens here all the time....If you use Resin Research Epoxy Resin and you learn the "Rules"......you will not have problems.....you still need to learn the Rules......
......and I have many posts and threads on Swaylock's helping people understand the Rules....
If you Lam with epoxy and hot coat with poly you do not understand..........ask any repair guy.....or a chemist. or Greg L.
Stingray.
Stingray - if you sand epoxy and rub with de-natured alcohol it takes polyester just fine - guess where it says that? On the bottle of epoxy
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Stingray - if you sand epoxy and rub with de-natured alcohol it takes polyester just fine - guess where it says that? On the bottle of epoxy
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no. wrong answer.
What bottle of epoxy? What brand? Prove it. Are you ready to get into a pissing match. Post photos....do I need to call out the big guns? ....Ha Ha ha.....you just made my day.....Stingray.....
No solvents. No sanding. Learn how to use RR and you can Lam and hot coat in less than 24 hours with a chemical bond you can trust....got it ....a chemical bond, lam and fill......Chemical bond....did I spell that right? Chemical bond.....
Ray....you are not an expert.
Epoxy glass job over poli foam yields an incredibly durrable board. I just don’t care for the extra work and discoloring that you get with epoxy. I’ve switched entirely to UV cure.
“…if I decide to gloss…”
Sounds like it’s not that important to you. That said, why tempt fate? Do the whole thing in epoxy. You don’t want any regrets when all you’re trying to do is take an extra step for aesthetics. Make one minor mistake trying to gloss with PE over epoxy, and your aesthetics are TOTALLY F’d.
I’ve actually gotten very good results polishing epoxy resin. No way would I try to use poli over epoxy. That’s just asking for trouble.
Recommended Uses:
SB-112 is specially formulated for use in building and repairing sail and surfboards over polystyrene cores. It can also be used for coating and composite laminating. SB-112 is unique in that polyester resins and gel coats may be bonded to it without the use of "tie-coats". We recommend that polyester be bonded onto freshly sanded SB-112 epoxy within 48 hours of cure.
(from System Three website... http://www.systemthree.com/store/pc/SB-112-c12.htm)
FWIW - I have personally polyester gloss coated over a sanded epoxy fillcoat many times without catastrophic failure. My worst issues have been with epoxy over epoxy. Any sort of amine blush (even with 'non-blush' epoxies and the use of additives) or prolonged delays between coats can, and likely will, create bonding issues. Adhering to Ray's and manufacturer's recommendations as far as ratios, working temperatures, proper mixing, etc is your best hope of success.
BINGO! It’s all about using the right product and making sure you follow all directions on the bottle - like lots of paints, many epoxys have a “window” in which they’re “fully cured” as in sandable, but still chemically green enough that it can form a bond with polyester - usually it’s within x amount of time or after y amount of time
Stingray and the Crew at The Low Tech Lab have an Awesome method for glassing surfboards. No solvents. No mixing up of poly /epoxy.....here's the link...
http://www2.swaylocks.com/forums/first-epoxy-glass-job-s?page=1
We learned it all on Swaylocks.com.
And today with the KK resin cure times are much faster. Same process. We have fully embraced cut laps at the Lab...Much cleaner if you wait...Thank you Paul Cannon.
Ray