Hi,
I make some parts using carbon prepreg (from Hexcel) and 3D printed Polycarbonate moulds. To make a glossy surface finish of the moulds, I use 2-3 layers of XTC 3D (more closely unspecified epoxy resin) with sanding between each layer. Finally I seal the surfaces with S120 Mould Sealer from Easy Composites (10 coatings). Resulting carbon part looks amazing, but I have a problem with the mould. The XTC 3D does not stick to Polycarbonate very well, so after demoulding there are small areas on the mould sourface, where the layers of XTC 3D are peeled off. Because of that, I can't use the mould again without any repair of the surface. Interesting is, that the resin from carbon prepreg stick very well to the Polycarbonat. On places, where is not release agent applied, I'm not able to peel off the resin from the surface.

Can someone recommend me some type of epoxy resin or gelcoat as a replacement of the XTC 3D? It can be also a resin from Easy Composites portfolio. I also require applicability of the resin up to 100°C and fast curing time (preferably up to 2hrs at elevated temperature - 60-80°C )
Thanks in advance!

Hello

I did a similar mold for trial.
It was 3D printed out of Polymaker PC-Plus
The cavities were sanded, then I used easylease as release agent. Once prepreg was cured, I had difficulties to pop the part off the cavities.
I sanded again the cavities and applied S120 mold sealer. Then realized after a second cure that the part pop off easily.
I will soon cure in a larger mold fully sealed with S120, so I can give a feedback.

I also used XTC 3D to smooth a PLA 3D printed pattern. I did not find this epoxy filler really efficient. Really long curing cycle for an approximative result.
I fully sanded the pattern and also used S120 which was perfect to build an epoxy mold out of the pattern.
However S120 is really thin so it cannot fil big surface imperfections. There is probably a better product for this but I don’t have the answer

The issue is the temperature requirement. 100C pushes you into the high temperature system realms. Eg our EL160 High Temp Epoxy Laminating Resin
which will go to 160C with an appropriate oven post cure.  However it is not particularly quick curing.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant