I was in Bunnings today looking for some bits to repair the nose of my board today, and came across something that's called "Fibreglass resin". It's used for fibreglassing. Perfect, I thought, for fixing my board.

Then I saw that it was 33% styrene, whatever that is. On the tin it says it's for fixing surfboards, but aren't surfboards a different type of foam to what we use on windsurfers? I know there are two different types of 2 part glue, one's called epoxy, the other one's called something else.

I got all confused, got scared that this stuff would eat up my board (saw some horror pictures on boardlady) so got some normal araldite instead.

Can you use this 'styrene' epoxy on modern windsurfing boards?

Hi Mineral1,

Yeah I know the stuff in a board is "polystyrene", that's why I was worried.

Also found this on the net at www.surfersteve.com/cgi-sys/suspendedpage.cgi :

quote:

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Epoxy resin is necessary because polyester resin has styrene in it and will dissolve the styrene in polystyrene foam.

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I'm still none the wiser?

I reckon that stuff is most likely polyester resin, the stuff most commonly used on surfboards and boats, and it can't be used on polystyrene.

quote:

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Originally posted by nebbian

something that's called "Fibreglass resin".

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Elmo put a lot of empgasis on it, I'm here to add some more.
Don't use it on polystyrene!!! it will melt it!!!!
That's what I hate about imprecise langauage it can get you into lots of trouble. There's no such thing as "fiberglass resin". Fiberglass is a cloth, resin is a liquid. There's several resins that can be used with fiberglass, polyester, (which as mentioned is probably what this is) polyvinyl and epoxy being the ones I know.

quote:

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33% styrene, whatever that is.
styrene is the thinning agent in the resin, and probably the solvent mainly responsible for dissolving polystyrene foam.

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but aren't surfboards a different type of foam to what we use on windsurfers?

yes and no.
early "custom" boards were made polyuethane foam, polyester/polyvinyl resin, you must have seen them around!
modern production boards are probablly all polystyrene foam epoxy resin.
A guide is the bung, if it's got a bung it's polystyrene foam, but be careful there's also a closed cell form of polystyrene that doesn't need a bung (blue styrofoam).

"2 part glue" does sound like epoxy, typically the ratios between part a and part b are from 2:1 to 5:1, araldite being a bit atypical at 1:1.
Polyester and polyvinyl are more like 100:1 resin to catalyst.
But I'm sure epoxy doesn't have styrene in it!

I wouldn't try mixing any liquid colours into any sort of resin unless they're for that purpose.
Colour is normally sprayed on afterwards with epoxy. I use 2 pack polyurethane. (and I guess this could also be classed as a 2 part resin, but I've only seen it as a paint)
Our local paint suppliers are very helpfull, when a very fussy mate dinged his AHD they were able to match the colour exactly and put in a spray can for him, not sure what sort of paint it was.

Unless you bake the epoxy for several hours, (don't go over 50C and undo bung!!!), best to leave it a good week before painting.

(Studiously avoiding thinking about any water that got in while it was dinged)

If you have got some water in it Nebs, you should be ultra cautious about vent discipline. If you leave it in your car with the vent closed you may well elmo it.

thanx ducat, might take a while to type with my one finger style, stay tuned!

lucky this is the not often visited general forum!

things are pretty cruisey round these parts!!!!

well,

for a start, polyester laminating resin in its raw form is used to laminate fiberglass cloth to a polyurethane (surfboard) blank after the correct amount of catalyst (mekp) is added. if the weather is cold then styrene which is a watery thinner of polyester (but should not be consumed internally like water under any circumstances)should be added sparingly to aid in releasing small bubbles from the weave.

laminating resin hardens with a sticky finish and the blank is then generously brushed with a finish coat of " wax in styrene "mixed with laminating polyester which allows the shape to be sanded, and finished with waxed resin or flat acrylic car paint.

epoxy is a whole new bag of worms.