I talked to a techni at Lange & Ritter about this for my next project and they have a polyester made specifically for this called T30. it’s on page 56 of their catalog. If you need help with translation PM me. I’ll be ordering some today to try.
http://www.lange-ritter.de/downloads/LR-Katalog_Polyester-Gelcoats.pdf
They will ship to UK.
Cheers
It does if you add a small amount of wax to it.
I would use Vinyl Ester as a gelcoat, it is compatable with PE and Epoxy, it also acts as a barrier between if you want to use all three…
Is it possible you could translate and post it on here for all to see? I tried a UK search, but it didn’t turn up much really, just these interesting looking toys:
http://www.gbr-jet.com/models.html 
Technically, that’s not correct. Duratec hi gloss additive can be mixed in to produce a hard tack-free finish. This way gel coat can be sprayed onto a finished part for color or as a repair.
Availability table Polyester resins (for epoxy laminates)
15.30A T-30 Transparent
Glossy, abrasive & impact resistant; visible carbon laminate top coat
Available in 220, 30, 5, 1 kg containers
15.30B T-30 white
White; for epoxy laminate
220, 30, 5, 1 kg
15.33B T-35 white
White, easily polished; topcoat for aeroplane
220, 30, 5, 1 kg
12.33 Thinner
Spay thinner for T-30/T-35
30, 5, 1 ltr
Recommended resin additive: 1.3 – 2 % Curox M-300
Usage: 500 – 800 g/m²
Pot life with 1.5% & 18-23°C: 15-25 min
Storage life: 3 months
Recommended Layer thickness: 0.4 – 0.7 mm
I couldn’t get the table to render properly so I hope this form is readable.
Cheers
DB
i would love to try a 1kg tub of the clear t30 but i reckon postage would be just as much as from the united states for this unfortunatley,
the topcoat i need as above needs to be thick enough so it doesnt sag on inclined surfaces, none of my bits have vertical surfaces bit some have say a 45 to 55 degree slope on them,
on another note, ive done a piece with no gelcoat or surface coat in the mould first so there is a lot of print thru, ive used SP115 epoxy to do the lay up, for the top coat can i use poly resin ? the resin i have is seabase 7x which is UV stable etc, i just dont know how the poly will react with fully cured sp115 epoxy
Matt
Thanks very much DB.
So in other words when using Polyester Gelcoat and epoxy it’s better to wait a bit longer for the gelcoat to cure and then proceed with the epoxy lay up (mechanical bond ???) instead of the semi-cured gelcoat and polyester resin application (chemical bond) Am I correct???