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.

Hey Hanaldo & Matt,

thanks for your replies!

I can confirm that these chunks of missing epoxy that reveal the glas scrim seem very familiar to the defects in the moulds I have made. However, due to the smaller size of my moulds I have had only a few of those larger voids in every other mould, so it is a bit difficult to compare to your mould. I experience these voids rather randomly, regardless of the corners, radii or flat areas. If your straight-forward geometry experiences similar issues, I don't think my the geometry itself is to blame for the defects. However, when I do have multiple voids they usually are in close proximity to each other, whereas the rest of the mould is otherwise fine with only a few dozen or so smaller pinholes across the entire mould. This too looks somewhat similar to your mould.

I haven't had the time to make new XT135 moulds yet, but my first change will be to make use of smaller panels of material as Matt suggested. But I find it super strange that such large voids are possible in a mould that is otherwise pretty decent. It is as if giant pockets of air get trapped under the surface ply, unable to be pulled by the vacuum pump.

As I do multiple XT135 moulds per vacuum bag, I am pretty sure the vacuum and the my bagging technique are not to blame. I sometimes get one XT135 mould that has maybe 30-50 tiny pinholes, but no glass-scrim revealed, whereas another XT135 from the same bag suffers from 2-3 larger voids, yet has fewer tiny pinholes, also in different locations than the first mould. Again; multiple XT135 moulds made in the same debulk bag, same layup, same vacuum bag, yet different results for each XT135 mould from that bag. Just very inconsistent.