Because most of my sculpture is designed in the round, this week it was time to try vacuum forming 2-part moulds with my tiny, ugly vacuum former.

All of the practise has paid off though, and I’ve been able to get decent moulds from a variety of objects that I’ve been thinking of casting for a long time. When it comes to moulding HDPE I’ve skipped the lamp and used the heat gun hand-held, which is what I wanted to avoid but what has worked the best.

So my only objective this week was to make a two-part mould that would be both cheap and food-safe. Not that I want to cast food items, but I want the option, and I need to find some use for this thing I rushed to make. I also thought it would be good to test whether expanding foam could be easily cast in one of these plastic moulds.

I ended up making casts of both my 3D-printed coin and of a trio of dried-up paint tubes. The paint tubes are part of a bunch I’ve been saving for some found-item artworks I’ve been planning for years… I really need to start finishing my ideas, don’t I?

After the paint tubes were successfully replicated on one side, I wondered if I couldn’t make a full cast of a tube to either use in pewter casting or for making a lost-foam positive for aluminium casting. Well, I managed to burn through an entire can of expanding foam and make an impressive mess, but apart from that I cannot yet attest to my achievements, as the stuff’s still curing right now.

So what have I learned from it? Yes, I can use HDPE to cast expanding foam and actually get it off, but it takes longer to cure than I expected. Apart from that, it’s not that all hard to make some quick and cheap 2-part vacuum formed moulds, so watch this space.

Last week

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