Just finished three boards glassed with RR epoxy. Two days later I sprayed them with a clear acrylic spray paint. 30 min. later they were as soft as plastic milk jugs. Has any one else had this problem?
Hey Tiger…
You saying the glass or paint is soft? Its a perplexing problem either way, but there’s seemingly no way a coat of paint can do that to an epoxy…
Josh
The glass softend up. One of the guys decided to surf one of the boards. It broke on a three foot wave. You could peel the glass off crunch it up in a little ball like a dollar bill. Really strange.
This is dead strange indeed…
EPS or PU shape?
I was thinking, if its EPS, maybe, maybe the lamination was so pinholed that the sprayed clear coat (if it was thinners based paint…) went right through and rotted the foam…But if you are an experienced laminator you would take that like an insult!
It can’t be undercured resin if you went right through to finish and it was sandable…
Yeah, other than that, I’m mystified…unless it was 1oz glass or something…
Josh
…But if you are an experienced laminator you would take that like an insult!
Thanks I am. No, not realy. No pinholes. The paint was thinner based. I haven´t been able to find water based lacquer down here.The foam under the glass was fine. It is defently the resin that got damaged. One thing it did occure to me was maybe the solvent used in the paint had a reaction with the UV rays. I am baffled as well.
May be time to call on the resident epoxy chemical Boffin, GL…
Josh
Sounds good. How do we do that. Do we start chanting or somthing like that?
S’pose you could chant…but PM’ing Greg Loehr would probably work quicker! LOL
Josh
I had to GOOGLE PM´ing. I´ll try that
thanks
Hey, sorry, yeah…
There I go assuming you been around Swaylocks since forever…
PM - Private Message…
Josh
Please don’t take this as an insult…I have some questions…working together we can build better surfboards.
Did you mix by volume per the Resin Research instructions ? 2:1 mix
Did you mix by weight? Did you adjust your mix to do it by weight ???
Did you slowly stir your resin for at least 4 min ?
Did you Lam and hot coat both sides of the board in less than 24 hours for a proper chemical bond?
Did you post cure? ( I don’t post cure) ( most pros postcure)
Did you do all of your resin work at temps above 65 degrees F…
Here’s my low tech guess as to what happened…The resin was not fully cured. The solvent in the spray paint ate into the resin…
But wait there’s more…
I’ve glassed Epoxy boards and they feel rock solid after hot coat…after power sanding the boards are not so rock hard…I think the heat from the power sanding softens the board…Think about it…I could be wrong…
…All my epoxy surfboards get a second coat of resin after power sanding with 100 grit…
Ray
Thanks for the reply Ray. All the resin was mixed well. All glassing was done in 70 to 85 degree weather in less then 24 hrs. the boards were very strong after sanding and they were painted 48 hrs after being sanded. I thought about the resin not being cured too, but isn´t 48 hrs enough? I used to post cure the boards but never found much benifit.I have actually over cooked one.Wasn´t pretty.Stopped doing that.
Mike
I reckon it sounds like Tiger is no gumby and he’s done the mixes right…
And I’ve found that if a board sands without gunking up the grit, its cured long enough.
Yeah, I’m wary of applying heat too…only gentle and altertnating warm/cool if anything. I’ve just moved back to a colder climate and coming winter will see me doing this.
I suggest you don’t lam another board with that particular jug of resin until you’ve gotten to the bottom of this.
Josh
Wow thats a new one, i’m interested to hear the outcome of this.
Thinners are often acetone based, which would screw with partially cured epoxy. But as has been said you managed to sand it ok, so it sounds like it got at least a fair way to being cured.
Maybe it was just cured enough to sand, but still green enough for the solvent ot affect it… I dunno…
Can you remember how it was when the sandpaper hit it? gummed up a lot of disks or not?
I guess I can’t help more with the problem, but I just had to mention that the “hotcoating within 24 hours for a chemical bond” is actually more problem causing than solving!
I don’t wanna piss anyone off here, but I feel that it’s actually bad advice, and people will get stung by following it, especially in cold climates and with cheaper epoxies!
Every thing was normal it sanded fine no problems with no gunking up of the pads. The paint was applied more then 48 hours after the hot coat.With 85f (30c) + degree days. RR resin with a dash of added f was used so it wasn´t any cheep stuff. I agree with Josh about not using any more of that resin, but unfortunatley I have to glass a board today. So I guess we will see what happens with this one. No clear coat on this baby.
I’d say find another clear coat product. I’d like to get the brand on that stuff to see what might be in there but our resin is used in gas tanks because of it resistance to solvents. This has got to be some really nasty stuff.
I was gonna spray a clear coat this week on my freshly finished epoxy board. I’m gonna rethink my options now. Sorry to hear about your loss.
May I suggest doing some tests with off cuts? See if you can recreate what happened, paying attention to the details along the way… and if it doesnt happen, well then you know all the details to make it work
Okay you were using RR epoxy with some F.
What kind of foam was it? Let’s hear brand names for the foam and paint. Maybe someone else can identify what’s gone wrong.
The foam was 2 lb. EPS. The paint was some brand I had never used or heard of. I think it was called THE GENERAL.You are probably thinking, “hell this guy doesn’t not even know what he is working with”. I didn’t. I was late making the delivery. Every where was closed. So I stopped into the only place open. Bought what they had. sprayed the boards and tossed it. Didn’t´t expect any problems.So I am not to sure of the brand. Next week I am going back to the city so I will pick some up. Do an experiment and post the results for all who are curious.