plug/mold surface finish for epoxy

[srimes]

I know you want a polished finish on a plug and mold for ester boats as that's what you end up seeing, but for epoxy layups you have to paint them after demolding. I saw someone on here mention that you don't want a super-fine mold finish for epoxy (I want to say it was Richard but I'm not sure). What level of mold surface finish is best for epoxy boats?

[War Whoop]

Originally Posted by srimes

I know you want a polished finish on a plug and mold for ester boats as that's what you end up seeing, but for epoxy layups you have to paint them after demolding. I saw someone on here mention that you don't want a super-fine mold finish for epoxy (I want to say it was Richard but I'm not sure). What level of mold surface finish is best for epoxy boats?

Not true ,I have pulled 41 foot Epoxy parts from highly polished molds.

[Herman]

You want highly polished. The only reason is that the better quality the surface of the mould is, the better it releases, without funny problems.

Afterwards you will need to sand the product and paint it, but so what? You will need to do that anyway.

If you ever need to make a matte finished product, you can use a matte mould sealer (Zyvax Sealmatte, for instance)

And if you ever decide to make a polyester part, you can start right away.

Originally Posted by srimes

I know you want a polished finish on a plug and mold for ester boats as that's what you end up seeing, but for epoxy layups you have to paint them after demolding. I saw someone on here mention that you don't want a super-fine mold finish for epoxy (I want to say it was Richard but I'm not sure). What level of mold surface finish is best for epoxy boats?

No, that was not me!

I would recommend a high gloss finish, no matter the resin one uses for the part.

And, as Herman said, you have to sand it anyway if it´s Epoxy.

[srimes]

OK thanks y'all, I stand corrected. I was just thinking that since the part would be sanded and painted that the plug and mold would be fine with, say, a 220 grit sanded finish. But if polished is better that's good to know.

Originally Posted by srimes

OK thanks y'all, I stand corrected. I was just thinking that since the part would be sanded and painted that the plug and mold would be fine with, say, a 220 grit sanded finish. But if polished is better that's good to know.

It releases much easier, and that is what you need first! No hassle popping the structure out.
The surface preparation, though important, is second.

Regards
Richard