It seems like the ideal solution for casting is a tabletop vacuum machine that allows to vacuum the investment on top of the machine and also support sliding in a perforated flask to vacuum the mold from underneath and sides during the pouring of the liquid metal. Here is a picture of a model that seems to be the standard at least for most hobbyist. It is made by Arbe USA.
I am sure its a great machine and I would love to have one BUT it is relatively expensive (> $1000), very heavy and I couldn’t find one in Germany. Shipping from the US would cost around $400 and customs would be a nightmare.
So … I had to find an alternative plan. My goal was to have the EXACT functionality, no steel soldering because I have never done this and last but not least cheaper to get.
Here is my solution. At least in my head:
1. Use a vacuum pot incl. vacuum pump like the following which is readily available for < $200.
2. Replace the glass lid with a steel lid that has an opening the size of the the flask diameter just like the Kaya Cast machine does.
This would allow to the the same vacuum pot for investment treatment when using the original glass lid and for pouring using the steel lid. I am making a mistake here? This should be 100% equal to the expensive machine regarding functionality assuming the same quality vacuum pump.
The only problem could be that the standard vacuum pump is not made for super hot air. But I will try and potentially get another pump.
The biggest issue was the perfect steel lid but I found a service that MAKES them after your specification for <$50 !!!!!! I ordered one with an outer diameter of 250mm which resembles the original size of my vacuum pot-lid and an inner diameter of 65m which is 5mm bigger than the flask I have started using for all my castings. The key was to find a pot that has the compressor connection on the side and not in integrated into the lid.
I can’t wait to get the metal disc and find out if my thinking was wrong . Here are two images showing the idea:
