I'm just looking into making a few parts (in my usual sloooow pace) and I'm considering core materials.  I appreciate the convenience of soric however I'm looking for your opinions on ultimate weight minimisation.  I cant really use honeycombs as I have a single mould so please restrict it to common cores.  I'm looking for a comparison between thinks like soric, balsa, foam etc as to what is ultimately the lightest moulding.  I appreciate the extra labour with foam of infuse/bond/infuse but its just for myself.  My suspiscion is it will be foam, soric, balsa in order but I'm happy to be corrected.

Thanks y'all

Without knowing more details we cannot really comment on what's the most suitable.



Aramid honeycomb.



Sure you can use honeycombs.



From light to heavy: honeycomb, certain foams, balsa, soric. Depends on the required thickness.

Thanks for the reply.  I'm looking at car bodywork so some flat(ish) panels and some complex curves.  I can use a variety of core materials for the different sections.  The current panels are 3mm thick GRP (made by closed mould).  For some I can go thicker but for some areas I need to keep 3-4mm thickness. 

WRT the honeycombs I've just found things like nida plast which are pre-skinned.  I've never used them so would appreciate some input on if I can use them under vacuum (ie wet out outer skin, bond in core and then wet out inner skin). 

I'm pretty sure can can't use noida plast under vacuum, it's for wet lay only.

Assuming your looking to replace non structural panels for me it has to be a combination of Closed Cell Foam and Soric. Closed Cell on the flattish/simple curve areas and Soric on any awkward bits. The foam will give you a hard to beat strength/weight ratio and the Soric will aid Infusion on the tricky bits. 2 layers of cloth either side of a 2/3mm core should be plenty. Most car panels have "designed in" creases/returns to add stiffness. You may have to build up thickness in certain areas not for strength but to maintain the fit/shut lines if your planning on pulling moulds from the original GRP panels.

Warren

Carbon Copies Ltd

Thanks Warren.  That was my original thought I just thought I'd ask to see if there was a lighter option.

If time is not an issue you can actually form closed cell foam into some fairly complex shapes with careful use of a heat gun and neat cutting and trimming. trim it roughly to size, heat it, clamp into position and leave to cool. The foam will then hold that shape. You then have to make up individual pieces and mark them so you can reposition them during lay up, a bit like a jigsaw puzzle. Very time consuming but actually quite satisfying as you end up with a very strong yet extremely light panel.

Warren

Carbon Copies Ltd