What foam do people use to make molds i have been asked to help make a body for a go cart
jacko

Last few days ive been looking into this loads ready for starting my bodywork...theres a few options depending on budget/quality:

The 'proper' way seems to be to use polyurethane (PU) foam. Places like here sell the stuff specifically for fibreglass mould making (good 'how to' videos too if you're interested): http://www.easycomposites.co.uk/#!/patterns-moulds-and-tooling

The cheaper way is to use phenolic foam. This is 'Oasis', the stuff used for flower arranging e.g. here, its available at loads of places: http://www.oasisfloral.co.uk/index.php?route=common/home

Cheapest is expanding PU foam, the stuff used for filling cavities. Its not the best though as the larger air holes created means using lots of filler

Those big sheets of insulation may also work, but you have to check what type of plastic its made from, it can be hit or miss....steer clear of polystyrene, that'll melt when resin touches it

Hope that helps I'll be using the Oasis 'dry' foam blocks

[Edited on 28/2/17 by christim]

Or go very cheap like me, depending on accuracy and quality required at the end. . .

http://www.locostbuilders.co.uk/viewthread.php?tid=207238