October 11, 2018
By Anthony Sobbi
At FLU we’ve been experimenting with a cost-effective method to make moulds for our carbon fibre parts. Here is our current process to make smooth carbon fibre or glass fibre pieces:
- Mill the mould from XPS foam and use 240 grit sandpaper to smooth out the mould.
- Use 400 grit to finish sand
- Use PVA wood glue to seal the mould. This prevents the foam piece absorbing the resin. Also requires less work than using gel coat.
- Use 240 grit to sand down the PVA and then use 400 grit to give it a smooth finish.
- Add mould release onto the surface.
Even though gel coat will give you the best finish, PVA works wonders! It’s cheap and very easy to work with.
We found that certain stores have different densities of XPS. In Australia for example, our major hardware store sells XPS but it’s horrible to mill. We get our XPS from a foam supplier that normally use it for building installation but it’s great to mill with. The density of their XPS is around 35 kg/m³.
We are going to be experimenting with a few new methods over the next few weeks so we will post up our discoveries as we go!