XPS Foam

Hi, folks,

Just finished shaping a home-made Dow blue XPS blank. Some of the Dow label is showing through on the deck. Can I paint this stuff to cover it up?

Hi, you can use water based acrilyc paint, with brush or airbrush.

Always test on a sample.

Regards Flavio

I wouldn’t worry too much about the label showing now. When you go to fix the delams, just sand it off then.

hi, you will have to put paint on pretty thick to cover the label if you are painting the blank. your best bet is to sand it out and make sure you leave the whole blank very rough sanded, no more than to 60 grit as delams are very common with XPS, I did 4 boards that way and they all had some delam issues, mind you they were my first 4 boards and maybe i am not the best glasser. if you think more sanding will mess it up you can paint over the hotcoat like boatbuilders do. good luck

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hi, you will have to put paint on pretty thick to cover the label if you are painting the blank. your best bet is to sand it out and make sure you leave the whole blank very rough sanded, no more than to 60 grit as delams are very common with XPS, I did 4 boards that way and they all had some delam issues, mind you they were my first 4 boards and maybe i am not the best glasser. if you think more sanding will mess it up you can paint over the hotcoat like boatbuilders do. good luck

Nope XPS definitely has some delam issues.

This was my cheap blank, all hand tool project. Dow insulation from Home Depot, Elmers glue from my daughters back back, 60 grit paper left over from refinishing my deck. Almost forgot the hunk of trim I used for a sanding block. Of course the epoxy was expensive (RR). I’ve heard about blowing agent and delam. I’ll take what I get.

I’m a first time epoxy user so I need a little advice. In the past with poly I’ve laminated the one layer of glass on the bottom, flipped and laminated both layers of glass at the same time on the deck. Can I do this with epoxy or should I do each layer separately? My schedule is 1 x 6 oz. bottom, 2 x 6 oz. deck.

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This was my cheap blank, all hand tool project. Dow insulation from Home Depot, Elmers glue from my daughters back back, 60 grit paper left over from refinishing my deck. Almost forgot the hunk of trim I used for a sanding block. Of course the epoxy was expensive (RR). I’ve heard about blowing agent and delam. I’ll take what I get.

I’m a first time epoxy user so I need a little advice. In the past with poly I’ve laminated the one layer of glass on the bottom, flipped and laminated both layers of glass at the same time on the deck. Can I do this with epoxy or should I do each layer separately? My schedule is 1 x 6 oz. bottom, 2 x 6 oz. deck.

You can Laminate the same as poly.

Slight detour…

Someone said he laminates, waits 2 hours, then hotcoats before cutting away the tape and excess glass.

Do you guys hotcoat right on a laminate that is not fully cured? I didn’t know that.

why use crap foam with expensive resin??

just go and get some eps

it is cheap and freely available

Next time, I’ll hotwire a block of EPS, I promise.

Another reason I tried the DOW foam was the ease of getting the rocker. During glue-up I just taped the sheets to the bottom of favorite board. Next, I cut the board in two, traced the rocker on some PVC foam (scrap from local sign maker) and used that as a stringer. Glued that up with some epoxy and tape one top of level horses. Still, the whole process took a long time.

Regarding gasses trapped in the foam, I shaped this in the midday sun over the coarse of a few really hot days. I wonder if that helped some of the blowing agent escape.

So, it’s safe to do a deck lay up of two layers of 6 oz. at the same time with epoxy? Any other tips on laminating with RR Epoxy?

okay mate

u can use the same teqnique for eps as well

u will be sweet with two layers at the same time i think

just heat the resin bfore u add the hardener and it will soak in better.

Peobus i haven’t tryed RR so i don’t know it’s viscosity, but i did 3*6oz without problems, the resin must be quite liquid so it can penetrate easily all the layers, check for temperature and gel-time.

Regards Flavio

speaking of labels

lovingly refered to as solarbo

for all eternity

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Slight detour....

Someone said he laminates, waits 2 hours, then hotcoats before cutting away the tape and excess glass.

Do you guys hotcoat right on a laminate that is not fully cured? I didn’t know that.

You may be thinking of a post or two of mine. I laminate epoxy at night & hotcoat in the morning - 6 or 7 hours. No flipping.

Lam tight, its still tacky but 233+ sticks around the perimeter just fine. Heat the hotcoat so it flows like water. Brush it on across diagonal going both ways & it’ll be gelling as you finish. Combination of heat/cooling & the excellent chemical bond into the not-quite-cured lam.

That night (2nd), flip, surform laps & tape line. Hand sand where the deck laps will go over the hotcoat just to roughen it up a little, but not really necessary because I’m inside 24 hours & still getting chem bonding. Lam the deck nice & tight, thenwake up early again & tape & hotcoat before work.

All my epoxy layers are then within 24 hours for chemical bonding. I tried this out because I didn’t like that if you Lam-flip-lam-hotcoat deck-flip-hotcoat bottom like poly, then your bottom hotcoat is a mechanical bond only.

I do have to surform the laps that went from deck down onto bottom hotcoat & then rehotcoat those, but it all blends in super nice.

Another neat trick is I just sealed an EPS blank with that white water-based Krylon. Sealed up, looking nice, even easier than spackle or epoxy/cabosil…Probably the lightest method as well.

Benny, did you mean Krylon, the acrylic paint? does that really work, I think I have only seen it as an aerosol. Or am I way off the mark.

thanks

Krylon - the spray paint from hardware stores - has a new formula without solvent-based propellants. Its water-based acrylic. It does not eat EPS nor does it bleed under epoxy.

Ok. This brings me back to my original question. I have just a bit of the “Dow” label showing through on my XPS insulation blank, along the glue line. In retrospect, I should have sanded it all off before gluing the sheets.

If I use this water based krylon to spraypaint the foam, will the paint deter from my deck lamination? I know XPS, blowing agent, etc.

Or, should I shut up and paint before the hotcoat?

Thanks again, folks.

Any thoughts, folks? May I paint before the lam?

I’d say you can, but that’s only an educated guess based on my experience with the Krylon water based & epoxy. I’ve never used XPS.

Do a test. I’m sure you have some XPS offcuts left. Just spray them & laminate a bit of glass on. Next day, try to break it & peel it. Either it works or it doesn’t. But if you don’t know, don’t try the whole board.

Sometimes asking is no substitue for experimenting.

Quote:
Slight detour....

Someone said he laminates, waits 2 hours, then hotcoats before cutting away the tape and excess glass.

Do you guys hotcoat right on a laminate that is not fully cured? I didn’t know that.

Yup, read that too around here somewhere. I’ve been doing similar. lam, flip, catlap, lam, hotcoat, flip hotcoat… but the first hotcoat down while the lam is still tacky to the touch. couple of hours with a fast epoxy

This worked well on the last 2. Makes it easy to get the lam, lam and first hotcoat down in under 24 hours. getting the last hot coat down inside 24 hours is a little tougher.