a lesson learnt the hard way

General Discussion
1

well today i was getting a xps board ready to gloss coat i glossed the top no problems. I had sanded the fill coat on bottom and was cleaning out a few small pin holes after the sanding. When i noticed something odd. i have been using epoxy for lams and poly for fill and gloss coats. i saw a couple of pin holes that look very odd so i got small drill and opened them up to find that the poly had dripped though on the fill coat and left a hollow under the lam ( smallish by the stingers). I was a bit gutted.

i guess the moral is check the lam real good before fill coat if you are "brave" enough to go poly over epoxy/eps

so i hope that this will work ok but i drilled the holes abit and filled them with epoxy, and in a few days will sand and then gloss coat.... hopefully with no troubles

hopefully i will be smarted for  the next one!

cheers antony 

2

I think its better to lam and hot with epoxy, then gloss with poly, than using poly for hot over epoxy lam.  I guess I never thought about that happening, 'tho.  Thanks for the heads-up

3

yeah i wouldnt poly sanding coat on eps unless i squeegeed in a thin layer of epoxy first. i did tell you that tho

4

yeah paul i should have done that, pays to listen to good advice not always the advice of the guys you buy product from.

 i ran out of epoxy and did not have cash 2 buy more and  thought i could get away with it. but lesson learnt for next time

heres pics of the damage 

cheers antony 

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5

If you run out of epoxy you can still use the crappy 5 minute stuff from HD, wal mart etc to float a cheater coat on there. a small tube is more than enough.

6

I have used 2 part polyurethane on epoxy boards for finish layer. Works out alright but very toxic stuff.

Is that one of those IXPS blanks? What’s in that last photo? Very advanced stringer setup? Stringer material looks kinda reddish? Can You please post photos of the whole board?

7

hi antony epoxy is too expensive  imo. 2 pound urethane foam from midget and polyester resin

is it half the price to make whats a probably a better board. imo they are trying to make money out of us as they are trying to sell us the next best thing.i just cant see the the point anymore due to cost and slow work times

i just glassed a wooden board in kinetics and im very unhappy with the result. laps are visible and so is the paper on the lam. my next compsand are going to be all polyester on the outside and cheap epoxy on the inside