Talk Composites - The Forum for Advanced Composites

What material to use to make cores?

http://www.talkcomposites.com/Topic39552.aspx

By atlantis - 11/24/2020 1:46:39 PM

I want to make parts for which I need a mould that has inside narrow areas where it will be hardly possible to get a bag inside properly, let alone get the mesh and peelply out afterwards. In such cases it seems to be a possibility to make a core first that will stay in the finished part and that is a little smaller than the mould to allow for the carbon material around it. Of course a second mould is needed to make the core. However I wonder what material the core should be made of. It should be pretty light, it must be possible to kind of cast it and it shouldn't be overly expensive. The first idea of mine was to use ordinary pu installation foam but probably there's other or better possibilities. Of course it would be super cool if the core would expand a little under vacuum to press the material against the mould but I don't know if this is feasible at all.
By SleepingAwake - 11/25/2020 9:03:51 AM

 
atlantis - 11/25/2020 8:05:06 AM
Sorry, there's nothing to take pictures from yet ;-)

Cast polyurethane foam is probably what I'm looking for, I remember that I've heard about a product called Foam-It some time ago but didn't make the link straight away now. It isn't easy to get in Switzerland however as you say, these foams seem to be rather a North America boat building thing. I could get it from Germany though I think. But this stuff is pricey too, if somebody knows a competitive product available in Europe please let me know.


https://shop.swiss-composite.ch/pi/Harze/Polyurethan/Schaeume/PU-Standard-Schaum-Arbeitspack.html

swiss composites does have some PU foam. It is rather light and might form large-ish pores. I would call them and ask if they would recommend this product for your application. they are always super helpful.

Ciao!