Bronze Casting

I have seen this process before, here. and also several times in my dreams.

This is a thousand year old process, and I love how It being approached from this modern digital perspective with 3D printing and digital model making.

This is also a time consuming process, and made me feel that my wax cast was on life support sometimes, just because of the painstaking process of getting the mould ready for pouring.

Creating the wax for this pour was just so painstaking I simply didn’t have the time to make more than one, so I only had one good wax to use. great!

IMG_1532Once thats done, we stuck our wax medals to wax trees and created supports and risers for air flow. I shared a tree with Hannah who had a fair few casts to go from.

Some people had multiple trees and many casts and components as to get as many attempts as possible at getting the bronze right. Very un-encouraging to me with my single cast.

What followed this was the pouring process, which involved creating a fireproof shell over the wax trees. This was not an easy process and I proved that by breaking to off two the branches on someone elses tree, luckily they were repairable and no harm was done.


The fans were used to help drying

This process of pouring was done about twice a day for a week, the eventual shells that were formed around the trees were thick and strong enough to now melt the wax out and be left with the negative imprint of the medals.

We now have shells in which to pour bronze into.IMG_1541

As we were setting up to heat the bronze I asked about how the bronze gets poured and how we can tell when the shells are full. The way it was described to me was that the bronze isn’t taking liquid form, its not filling the shell like a liquid its still a solid its just being pushed down and compressed by the weight of itself, though it does appear liquid like, this apparently isn’t the case.

So we heated the bronze up, it took about an hour to reach its melting point in the crucible. at this stage we were required to wear fire proof suits. We had to scrape the scum off the top of the molten bronze. then with two people carefully but quickly pour the bronze into each cast. Doing a pour myself I can say it is very hot even in the suit and it is not easy to pour quickly for fear of it missing the cast.

IMG_1623Luckily the pouring went well.

Getting to smash open the shells with a hammer after such a delicate process feel like a sin almost. But thats what we did next. And luckily for me my cast turned out perfect.

Over the moon!

Over the moon!

I cut off the risers with the angle grinder and started filing down the sides to get it all uniform and flush.

After sandblasting I touched up the detailing with the dremel and spent a fair amount of time on making sure the areas for the slabs were smooth and straight to fit the acrylic slabs. Sandblasting creates such an unusual effect, its like a lifeless gold it is such a powerful process.IMG_1648

There was unfortunately a little air hole on the side where the bronze didn’t get to, I was shown a technique to fill the hole. Dremelling a small slither of bronze, plugging the hole and then smashing it with a hammer, seemed to cause it to fill. Filing over the top left no trace its a technique thats thousands of years old I’m told. bronze hole

IMG_1677The last things I did were the quote which I stencilled on then stamped with some stamps and a hammer, not easy and unfortunately not as straight as i’d had hoped.

And the patina, Oh boy crushed for time when doing this, just an hour and a half left from the deadline I was applying the patina and it came out purple and black.

Luckily scrubbing with some steel wool, really brought it out, the patina really highlighted and defined all the detailing and made the medal look very characterised and dramatic, very pleased with the outcome!



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