Thought I’d throw this out there to the swaylocks universe to cop some scathing replies from legendary builders about where I’ve gone wrong.
This build is riddled with faults, but this one in particular I’m not sure of how to deal.
Taped up a pin line (which bled yayyy!) and as I pulled the tape off the hot coat came with it but only in parts. I scuffed and cleaned before hotcoating bit obviously not enough. Next time I’ll do the “hotcoat when lam is still tacky” thing.
I’m using Trojan epoxy laminating resin, it’s the second time I’ve used it. UV stabilised lalala. Using it cause it’s cheap (I know I know probably should use a proper surfboard one etc etc)
It’s onto balsa over a low density EPS foam.
Not sure whether to sand back to where it grips, clean and re hotcoat, or just sand back to where it grips and put and acrylic seal coat cause I cannot be arsed at this point and plan on trying to destroy it trying airs etc.
Any ideas?
Attached is a pic, thanks in advance for the knowledge.
prep surface problem for sure. Low price epoxy use free amine hardener tech : skin sensitizer and blush easily, it’s your problem, you must remove blush with water before sand and recoat.
Now, scrub all surface with a scotch brit and water (some add a bit of soap) dry and sand all with 80 grit up to lam, do a new coat. Sand up to 400 and do your pin line.
Hey NDsboards
Are you from Newcastle? just saw you are using Trojan? So thought you are from there?
What Lemat is saying is right with with the epoxy you are using.
it can be saved, but would recommend trying some other brands of epoxy to get a better result on your next board. We are local also (central coast) and could point you in the right direction with epoxies if you need.
Hi Ndsboards - It does look as if there was an occurrence of amine blush. It is a common thing with certain epoxies although not unheard of with even ‘blush-free’ epoxies. Cold temperatures and high humidity can make matters worse. I have had it happen with ‘blush-free’ epoxy even with the additive that supposedly helps prevent it. Glassing in warm dry weather and applying the fillcoat as soon as the lamination starts to cure has helped me avoid the problem. If you try searching for “Lam-fill-no flip” method of epoxy glassing you might find more info. With your current situation, I suggest you sand down to the fiberglass - just ‘kiss’ it, don’t remove a bunch of the glass. Once it is scuffed, apply another fill coat. If you waited awhile and laminated both sides before fill coating, test your overlap. In my case I experienced delams between my top and bottom laminations along the overlap. If it looks like the overlap is affected, try grinding that away and do another layer about 4" wide down the length of each rail before the fill coat step. Scrubbing and scuffing before the fill coat may be necessary if your epoxy is prone to blushing. If you apply a coat of your epoxy on a clean piece of cardboard or wood, wait for it to cure and it feels ‘greasy’ to the touch, you have an epoxy that is prone to blushing.
Hey mate bummer about the amine blush issues! I’m in Tas and have had similar problems in the past and especially over winter, all to do with cold temperatures and humidity! I have it happen with surfset too I think it is unavoidable sometimes, luckily if dealt with correctly it isn’t a big deal.
ive done an epoxy sealer coat over my eps and dont have the cloth to lam it just yet, so i hope this doesn’t happen to me;( be a bit hard to do too much of a sand before i laminate. as the sealer coat has soaked into the foam fairly well. (thats kinda the idea)
its under a building with fairly low temps, all i can do is make sure its all gloved hand handled and maybe ill be ok.
The cloth from sanded has been shipped today so hopefully it will be here soon.
Common Australia post.
Wash blush before sand. Dry sanding doesn’t clean blush only clog sandpaper and spread more on sanded surface. Blush is easily disolve by water. Near all epoxy can blush, but in good weather conditions blush free ones less to no. Blush mostly appears at the end of resin set process when resin go from tacky gel to soft untacky.
Yeah so I am finding out!! Ha! No wonder my crease fix worked so well on my LFT sci fi, I was keen to get it back in the water so would’ve hotcoated a lot sooner after lam.
