liveforphysics said:
One would be best off not guessing with a foam they think will or will not have safe levels of compression-set.
Get the relevant compression-set % data. Ensure you crush it by more than that amount if you want it to keep your cells connected long-term.
Simply checking material property datasheets are really the difference between a long-lasting great pack and a potential home fire, spend the effort to use proper materials.
I totally agree with you lfp, but none of the NZ based suppliers have any data sheets listing compression set on their websites, and the ones I contacted via phone were unable to provide solid info re compression set either.
I have considered buying the same stuff that 'snath' used and contacted McMaster-Carr via email about purchasing some and shipping to New Zealand. Their reply was quick but extremely unhelpful:
"Due to the complexity of U.S. export regulations, McMaster-Carr accepts international orders only from our established customers. This decision also applies to orders shipping within the United States, because it is based on the final destination of the items. We will not provide a quotation or accept your orders."
So much for that...
The foam itself is not that expensive ($6.60 for a 12" x 12" sheet) and I imagine that if it was folded or cut to fit a big size envelope, mailing it would not be too horrendous either.So if there is a kind ES (US based) member who is willing to help out here, please PM me. I'll pay all costs upfront (Paypal would be easiest).