Hi John,
I agree Araldite will stick most things but it won't stick thermoplastics such as polythene. For mixing I use pieces of carrier bags, NOT the supermarket ones that are biodegradable but the heavy weight ones. Best thing is they are free! Alternatively a piece of paper works quite well, is also free and can be thrown away. Or do you have a use for the hardened adhesive on the mat? If so the polythene option can be shaped to some extent.
One warning if you do use something from which the hardened Araldite can be 'peeled' - the hardened edges can be razor sharp! That's one reason why I would use the paper mixing sheet.
One other tip when using epoxy resins, use a warm air source (hair dryer, or heat gun on low setting) and play it over the joint. The heat makes the adhesive more runny so it will find its way into the joint, or if you are using for inlay work, it helps it flow round the slot. But don't get it hot or you will get air bubbles.
Hope that helps,
Paul
Woodcrafts
