I have made kiteboard using vacuum bagging
Stack was as follow:
vac bag
matt which soak resin (I forgot eng name)
perforated film
2 x 200 g/m^2 glass fabric
wood, second side symetrically
As resin I used epoxy (with styrene), room temperature 17 deg, after applying vacuum I started to heat with something like this for about 5 hours (about 40 deg?)
This is how it looked like in bag photo
After opening it loocked like this: photo photo
What happened? can I rescue it somehow? Maybe covering with polyurethane varnish will bring it to life?
How should I avoid this next time?
One more thing, I realized, that heater turned off after 1,5 - 2 hours. Mayby that caused that resin shrinked?
After reading this post I found out that maybe film was too perforated?
A newbie at this myself but plwood is like a sponge so it needs to be sealed first before you do any glassing.So a coat of epoxy let that cure sand it then add glass and vac bag.keep pressure below 50% so you don’t suck out all the resin.
If a clear finish is what your after then you’ll have to start over.
I agree with mike, you should hot coat the wood first. To seal any pores and prevent any infiltration of water if it does make it through the laminate. ANd as mike pointed out, it might be giving off air under vacuum.
I don’t think your piece will be salvageable, as you have air inside your laminate.
If you’re doing a wetlayup you hae to be extra cautious about air bubble entrapment. The air could have been introduced in layup or as mike pointed out, maybe the wood gave it off? ALso if you’re using styrene, that could off gas as well.
I missed the heat thing.As sam pointed out you got out gassed.Wood should be heated first then apply resin and glass as it cools this pulls it in.Do not heat after.
If a clear finish is the goal then no need to vac bag,just apply light glass let tack up then another coat of epoxy and cover with a mylar film.This will yield the glossy surface your after.
Thabk you for all of your answers. I’ve read them after second laminating, but it is still good lesson for future
Yes, Polish trade mark is Epidian 53.
I don’t know… I don’t have vacuumeter yet, but now I know that I need it
Do you know any electronic one so that I could assemble presostat?
This was the biggest problem. During second laminating I covered plywood with one layer of epoxy, then I heated it for one hour (till it got semi dry) and then I continued with glass like previously.
On second board I didn’t have bubbles on surface but there were several inside - those could be from too big vacuum or styrene?
I was heating in order to shorten time of drying.
I think bleeder took as much resin (during first laminating) as it should, but later when I heated it, plywood started to soak and it created air gaps on surface.
Is resin infusion more resistant to such problems?
In the translation to English it does mention styrene ??
it does say its a room temp cure.so try not to hurry things.
Try a piece of scrap,do a hot coat let that cure or at least dry to the touch this may take a few days. do not heat!!.Then apply another coat followed by some plastic sheeting , a thick piece will work better lightly apply pressure to remove any air bubbles again let that cure.Peel the plastic off and you’ll have a nice flat shinny surface.
Remember to mix gently use a round stick so you don’t create bubbles in the mix. You can warm the epoxy before you mix it up this will make it thinner so it flows out nice. But don’t heat it after you’ve mixed it
I looked at this epidian 35 so called epoxy. Says you can vary the hardner from 50-80 parts and with the mention of styrene this is probably Ve resin badged as epoxy.
As far as I know poly and Ve resins don’t stick to well to plywood. So you may have the wrong resin.
