Originally Posted by josh18
................ I know Adam recomends it but I though I'd heard him say in the past that he doesn't like epoxy based tooling coats because they are hard to polish. .......................
Just repeating what I may have answered before here Josh: if you want to mould as "professionally as possible", as you mentioned previously, you need to make the necessary decisions. One or the other. From start to finish.
That is why I suggested you follow Adam's recommendation to the last detail. If you require polishing at the mould stage, the plug finishing and/or the release system has been compromised - by definition.. Not professional in the fullest meaning of the word, I would suggest.
My methods and my skills are still well and truly developing. I continue to use wax and PVA, which a more professional moulder would not. When and if I gain the necessary skills to avoid the more fundamental pitfalls and I can afford the semi-permanent release systems, I will progress to using them.
However, there are mitigating circumstances, I have no one around me within 500 klms who might share a 5 ltr. container of Frekote or Marbocote, both of which I understand have a limited shelf life. These economic factors have to be taken into consideration before making the crucial decision. I'm a retired pensioner with a limited budget.
If you really want a polishable mould, use polyester gel coat followed up with Vinylester Resin and chopped strand mat. I've used it for fuse moulds and will be using for the fuse for this plane. I understand that the gel coat is polishable.
After all, how many parts do you expect to manufacture from your proposed moulds? This is relevant to the set of choices too!
edit: I was posting at the same time you were. Some of the above may be irrelevant or out of order. My apologies if that is so.