Seal EPS to coat with polyester, what coat would you use?

General Discussion
1

Hi all,  what kind of coatings would you use to coat EPS for polyester?

I’ve read that PVA glue could make, or even painting after it.

Any suggestions? Better bonds?

I have discarded using epoxy because of many problems with supplies here where i live, maybe in the future.

Also, i will be using 10 kg/m3 EPS, although I know it would be better a higher density foam.

I am doing many tests, i tried pva glue + a bit of microballoons. It seems rough and white, not just only using glue.

It would be a short life board, i dont care about delaminations very much, i care about weight and performance.

I will be using wood fins (thanks Bert Burger)

 

Thank you all for your innovative attitude 

 

2

Bad idea. Get your hands on some good epoxy and read the instructions.

If your in Oz PM me and I might be able to help you getting some RREpoxy.

 

3

EPS and Polyester DO NOT MIX!!!

ken

4

I’ve heard of using pva glue. Never tried it, but always wanted to. Try it out on a sample piece. Let us know how it works :slight_smile: -Carl

5

you make the board in EPS and then paint it with a water ink for painting;

 

it will make a good cover that doesn´t have any problems with polyester; also, if you want, you can paint with different colors...

One thing: this doesn´t means that it will be a good board construction

6

Thank you Luis, I guess you are from Spain, aren’t you? I’m from Bizkaia, Vasc country.

You said it is not a good construction… because of bonding between materials?

Have you ever made one of this type? Further delaminations?

I have read about spackle (masilla), polyurethane / polivinilic / water paint, white glue, and so other coatings.

I will make tests for every one of them and will see.

Thanks to every one in this forum.

7

Oh I forgot, EPS I purchased is 45 kg/m3, pretty dense and stiff.

Sorry for conversions, anyone could post a table with metric and english pounds/cubic feet?

Thanks again

 

8

surfinmuskiz,

Greg Loehr will be able to tell you all there is to know on this. PM him if he doesn't chime in on this.  I understand that you can't get epoxy where you are located so it is cool  that you are able to improvise.  Are there no boat epoxies available there?

Dave D 

9

45 kg/m3 = 2.8 lbs/cu ft

One of the more dense EPS foams. 

Try searching the archives.  I seem to remember a guy painting his EPS blank with some sort of paint before glassing with polyester.

10

I've tried quite a few methods, including water based, and none seal eps 100%, even epoxy slurry did not seal 100%. Tiny holes you never see.

 

Persoanlly, not worth the risk. All your hard work shaping is not worth watching melt away.

11

I think the guy that was doing it on here years ago was using water based house paint, I think the thread was called the '$30- surfboard' or some variation of the $30- was in the thread title.

I think he may have used multiple layers of paint, for an adequate seal, before glassing.

Definetely not a preferred method, but I think if thats your only option then go for it. Would def be better to use UV cure and work real fast and get it out in the sun quickly to flash it off incase there are any pinholes in the seal coat.

But really would be better if you can get your hands on some epoxy, pref RR.

Paul

 

12

[quote="$1"]

Hi all,  what kind of coatings would you use to coat EPS for polyester?

I've read that PVA glue could make, or even painting after it.

Any suggestions? Better bonds?

I have discarded using epoxy because of many problems with supplies here where i live, maybe in the future.

Also, i will be using 10 kg/m3 EPS, although I know it would be better a higher density foam.

I am doing many tests, i tried pva glue + a bit of microballoons. It seems rough and white, not just only using glue.

It would be a short life board, i dont care about delaminations very much, i care about weight and performance.

I will be using wood fins (thanks Bert Burger)

 

Thank you all for your innovative attitude 

 

[/quote]

 

Hi ,

I'm new to Swaylock's and I want to build a Piece Of Shit surfboard using materials that are not made to be used together. Can you help me? I know from my research that Polyester Resin will melt EPS foam. I am more than willing to waste my time fighting with poly vs eps. I'm sure someone out there is building Piece Of Shit surfboards that can help me. Will you help me?

 

EPS foam...Epoxy resin....done deal

EPS foam...Polyester resin....POS......

13

someone beer ray.

14

In 1958, one of the Windansea ''regulars'' brought a shaped Hobie foam blank for all to see.   It was a styrene based foam that had been coated with epoxy (an ugly yellowish color) and rough sanded prior to glassing with polyester resin, the standard of the day.   That is the reason so many of the early Hobie's were covered with ''easter egg'' opaque colors.    To hide that yellowish color, as well as voids caused by pin hole seeps eroding the styrene based foam core.  

15

the first thing that came to my mind..

 

 

why?

 

and pictures of your tests would be nice.

 

agur....

 

 

 

 

 

16

Thanks for your opinion. Perhaps the next time you don’t have anything nice to say, don’t say anything at all. -Carl

17

I would seal it with..WOOD!

then glass as usual...

 

 

18

Yep,I’ve got one,eps core with 3/32"thick cedar skins glassed with polyester resin.I did use epoxy to attach the cedar to the foam though.

19

[quote="$1"]

Yep,I've got one,eps core with 3/32"thick cedar skins glassed with polyester resin.I did use epoxy to attach the cedar to the foam though.

[/quote]

Pictures? how does that board work? I've been toying with the idea for a while, but using gorilla glue under vacuum to attach the skins and build a very thin square rail line, then build the rails as in a hws.

20

Here’s a few pics,the board is a little heavy for a 6’0…almost 8 pounds I think but it takes a hard hit from a hammer to dent it.It doesn’t float me,I need to loose like 10 pounds.Its currently for sale and I can’t even fetch 200$ for it.