Hello, I'm currently making brackets for kart parts by the means of resin infusion. I have successfully created a 3mm thick metre square piece with perfect finish etc. I have purchased a line bender for plexiglass etc for simple bracket mould making. I am using 4mm clear low impact polystyrene as my mould. The bend works perfect, however when I apply easylease chemical release agent it appears to shock the bend and hundreds of small cracks appear across the bend only. The rest of the sheet work fine. The release agent and sheet are the same temperature (20). Could this be an incompatible release agent for clear polystyrene? Should I use a higher grade of thermo plastic sheet and a wax release agent instead? Please help! 

It is likely one of the solvents in the Easy-Lease is attacking the surface of the polystyrene hence causing the stress cracking you are seeing. If it is merely barely visible stress cracks then i would continue to use it until it fails.  If/when it fails, maybe use polypropylene sheet as it is resistant to the solvents, can be bent with heat, and also is unlikely to need any release agents as most common resins including epoxy, vinylester and polyester do not stick to it.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

you might also use a Water based release agent. like: https://shop.hp-textiles.com/shop/Formtrennmittel/Formtrennmittel-95/Hochglanz-Trennmittel-HP-HGR5.html
as your current mold is damaged anyway, you can calculate, wich option is the cheapest.