Casting Brass Chess Pieces- 2

by John

OK. So I hope that you saw the pics of 3d printing the pieces, then making some trees using the PLA pieces, wax parts, steel cylinders etc.

Today I mixed the water and Jewellers Investment powder, and poured the mixture into the cylinders. This was the largest volume of mixture that I had attempted.

1.5kg water, and 4.25kg of investment powder.

I keep a record of every mixture, every metal pour.
The rubber tub is for the mix. The vacuum pump and container are to extract as much air from the mixture as possible. The pump is 1hp.
Making the mixture, degassing it, and pouring it, is a tense time, so no pics. This shows the scales for measuring the weights of the water and investment powder. I use some old beaters to do the mixing. The degassing. Then pouring into the cylinders.
After an hour or two, the rubber base is removed, showing the trunk of the wax tree, and the metal pouring funnel.

The cylinders are placed in the potter’s oven. I have set the timer to commence the burnout at 6am tomorrow, at 250ºc. The funnel is upside down, so any melted PLA of wax will run out onto the bench. I leave a slight gap in the door closure. I will arrive at about 9am and complete the burnout at temps up to 750ªc, then do the metal melt and pour 4-6 hours later. Wish me luck!