Resin Casting Question

[blekk]

Hi all long time reader first time poster I have a question for all you resin casters out there. Im about to cast a clear epoxy resin piece (it's a carry handle about 150mm x 80mm x 80mm), with translucent pigments that will be exposed to long periods of UV (sunlight), and saltwater. I have read that a lot of clear epoxy resins 'break down', loose colour or go yellow with sun exposure over time so I would need a gel coat of some sort. So because it will be exposed to saltwater should I use a latex or urethane gel coat and would it be ok to do a second 1-2mm cast over the epoxy cast for my gel coat? I also want it to be quite durable and scratch/shock resistant. Thanks in advance for your help all.

 

[TheHeroOfCanton]

Hi Blekk,

Thats a very interesting question. I've used a few opticlear type resins before, and haven't noticed any fading. But the gelcoat question is interesting. If you're in the UK, give Mouldlife a call and ask their advice, they're always really helpful when I have a question.

Will.

 

[robn1]

Smooth-On makes a clear resin that's UV stable.

Polytek's clear resin can be combined with an additive for UV stability.

 

[blekk]

Cheers for the reply Canton. Im in Australia so a phone call to the UK will be a little expensive at this stage

 

[TheHeroOfCanton]

Ah ok, your best bet is robn1's links then. Those look ideal and you're probably better off buying from the US if you're in Oz.

 

[Wesman]

Hi, blekk--

Yeah, check out Smooth On. Make sure your mold rubber is compatible with the resin, though. I've used some water clear resins that required platinum based silicone, or at least bake out the tin-based to cure it. Also, I'm not sure about your use of the term gel coat. I thought that was a polyester based product. Do you mean a clear coat with a uv barrier? --Wesman

 

[blekk]

Wesman I think your right! Clear coat UV barrier with latex or urethane resins