more Q's about resin

Gday guys,

I was at a local shapers yesterday and he was preparing for a Lam coat on a board. As we spoke I noticed his resin was as viscous as warm motor oil, he also added styrene to his mix with 2% catalyst.

As a novis board builder/ glasser I was a little confused. I have just completed a board, the first I have glassed, and the resin I used was the viscosity of treacle and was much more difficult to work through the weave than this runny mix I witnessed.

Can any body tell me what effects this would have on the strength/bond of the lam?

Would more resin soak into the foam even if 2% mekp was used?

Why add extra styrene to an already runny lam resin? I thought this was a no no

And last but not least styrene is an additive to assist sanding and thin resin or am I mistaken, so why add it to lam resin?

Here are the results of my first start to finish board.

So a big thanks to all the swaylockers whose advise helped me along the way…nadles

Photo’s failed here we go again

Why didn’t you ask your local shaper on the spot?

I would!

Temperature can make the resin runnier as well.

G’day Nadles,

First board looks great.

Some glassers add extra styrene to thin the resin.

wax is added to styrene and then added to lam resin to create a filler or sanding resin. the wax creates a layer over the top of the resin stopping the air from getting to it making it easier to sand.

Dont add wax and styrene to your lam resin when laminating you surfboard as the filler resin wont stick without a hell of a lot of sanding.

The way Polyester surfboard resins are now there shouldn’t be any reason to add a thinning agent to them unless the resin is getting old.


Thanks Darren,

That’s what I thought, I bought my first lot of resin from dion chemicals and used it on a hotter day than yesterday I’m not sure where these guys bought their resin from but out of the can it was way more runny.

I build my boards in the back yard so I have not much idea where to source good materials here in NSW.

Don’t know if you have any tips. I’m from Sydney


Gday sandman,

I did, and he said he preferred it, but what effects does this have when laminating? He was a little preoccupied to talk too much though so I split. You can sort of tell where your not wanted…

I get my poly resin from FGI at Brookvale, through a company called Newkem on the south coast. Poly blanks from surfblanks at Brookvale. I only use the very best materials for building surfboards and it can all be found in Sydney.

you might pay a little more for the top shelf stuff but its worth it. Surfblanks and Dion are excellent places to start for sourcing all the gear.

The guys at shapers Aust. have all the stuff you could ever want when it comes to building boards in any construction you can think of.