Hey guys,

Is anyone else using XT135 yet? How have your results been and what materials are you using for your patterns? 

I have been trying to make some moulds recently, and have used a bit more than 1m of the surface and 2m of the backing ply just making relatively smallish moulds (8 different moulds in total), but I haven't managed a single decent result yet. Every one of them comes out with pinholes, not all over the mould but enough to render them unusable. 

I am sure of my seal and I am sure of my oven and temp stability, so the one thing that I am unsure about is that I'm not using the XT135 with epoxy tooling board as being in Australia I don't have access to the S120 board sealer. So I have been making my patterns longhand by creating an initial plug in the conventional method of PU foam etc, then making a vinyl ester splash mould, and finally using that mould to infuse a new epoxy pattern. The epoxy patterns are great surface wise and cured up to 90 degrees for 24 hours, so shouldnt be any concerns there. Any Easy Composites staff reading this, are you aware of anyone else using the XT135 in this fashion? Can you see any reason this would cause issues? 


Does anyone have a solution for repairing these moulds to salvage them? The user guide states that they can be filled with a high temp epoxy gelcoat and sanded flat, but then the surface can't be polished up again and the S120 is needed again to bring the gloss back - obviously not an option for me. Has anyone tried flatting and polishing the surface of XT135, is it worth an attempt or no? Anyone have any other viable ideas for smoothly filling these pinholes? 

Will post pictures when I get a chance.

Thanks guys,

I'm again quite confident that overworking the material isn't the problem, as this is something I'm very familiar with from when I first started using pre-preg. I know I did used to constantly reposition and slide and poke and move the pre-preg around, but that's something I'm very careful to avoid these days. Those flatter areas on my mould I barely worked at all other than just a firm pressure with the palm of my hand to warm the material slightly and get it to stick to the pattern surface. The trickier areas I used a dibber, and I was quite forceful there but as you said Matt, there's no pinholing in those areas. Then once the entire surface ply was down, I just placed the perf release film on and used a piece of breather with some light pressure. 

Cumberdale, the flat sheet was just a simple copy of the layup I've been attempting on my actual patterns, ie. One layer single piece surface, 2 layers backing (one layer single piece, one layer was in 2 pieces) perforated release, breather over the whole lot. Only difference is I used flash breaker tape around the border to prevent excess resin bleed. Didn't really use any pressure on the surface ply, just enough to get it to take to the glass plate rather than my gloves!