Mold making foam core

General Composites Discussions Composites Talk
#1

Has anybody used any of this?

http://www.spheretex.com/en/produktbeschreibung13.html

At the composite show in Orlando last year I meta fellow named Neil and he showed me how this material can help manufacture molds quickly. He came by with a few yard sample for me and explained to me that when I use this in mold making I need to do two layers of 1.5oz matt, apply this around the flanges and flat areas, and then two more layers of 1.5oz matt and walk away.

I tried this on a small mold and I was amazed at how strong it was, but I have not tried this on big molds that I will be relying on to make quality parts.

My main concerns are
-Warping over time
-Becase the core is so thick, could all the resin absorbed into it overheat during cure?
-Its a Chinese material, (I can’t find it made here in the US) Can I trust it?

What are your thoughts? I have ALOT of molds to make over the next few weeks for various jobs.

#2

Here is a photo of the material. The way I wet it before is I’d wet one side with resin over a piece of card board, flip it, lay the other side, then apply it to the mold with some light rolling.

http://smic-market.com/212-home_default/sphereax-s-tolshh-3-mm.jpg

#3

Wow that stuff looks awesome! Is it expensive? I’d love to use it if it is cost effective. I know there is a member on here that sells core materials from china maybe he could look at it… Funny his name is Neal too.

#4

If it’s the same stuff I get locally (it appears to be) then I’ve used it before. To be honest, I wasn’t majorly impressed. As you say, it works alright on small parts where the resin content is relatively low, but you lay up a larger mould with it and I suffered print-through issues. I prefer to stick to the old fashioned methods.

#5

Looks like Coremat with stitching added. I would be very careful when applying. Ensure good contact with the surface. Watch for the material spring back, especially around sharp male radii and all female radii.

Small molds are easy enough but I would be concerned about larger molds that suffer any type of torsional or flexural loads (like a boat hull mold suspended from it’s ends).