Which epoxy resin can be used on polystyrene/epoxy (firewire) surfboard (used for kite surfing as well)? Just tried Epiglass HT9000 epoxy resin and it started to eat my board away. Put my front heel through the deck of the board on Saturday. Hardly used the board so not a good advertisement for epoxy boards considering my old standard fibreglass board has handled the same treatment for much longer (with a depression at my heel position). Maybe the softer type board is better. Will get a depression but mightn't crack through to the core like the harder epoxy types. Anyone had experiences using different types of surfboards for kitesurfing? Or is there anything can be done to toughen them up post purchasing ie add a couple of layers of glass in foot positions or some type of pad? i like to use the same board for surfing and kitesurfing as I travel a bit and it is difficult travelling with more than one board so a permanent pad is no good.

decrepit said..

No pure epoxy resin should affect polystyrene. Maybe your resin has a thinner mixed into it, that could do it. I've never had that problem and I've used lots of different manufacturers. West System is very good, the only problem is the 5:1 mixing ratio makes accuracy a bit difficult with small volumes, (and if you want a good job, the more accurate the better)

Its easier to buy syringes from the pharmacy and use it to mix West System if you are using small volumes. Syringes are really cheap so you can throw them away if you want to, or just keep using them. A 20ml and 5ml should make it easy.

Epoxy Brands I have used with success are:

West system
Fiberglass international R180 (a bit thick)
and Kinetix (shapers.com.au/glassing/)

Remember resins like epoxy exotherm (heat up) when curing. If you need to fill a large space like a heel compression etc you may need to mix filler (microballons) with the resin and make sure it does not get too hot. Use a slow hardener, do it at the coolest part of the day and maybe think about a fan to blow on the repair to remove excess heat. If it heats up too much it will melt the polystrene foam - I learnt the hard way totally killing a shaped & glassed board when installing FCS plugs on a 35degC day.

As far as strength goes epoxy as a resin itself craps all over polystyrene. Strength of a kite/surf/windsurf board are a function of the composite system - glass/carbon, resin & core materials.