13-10-2023, 02:58 PM
(This post was last modified: 13-10-2023, 03:02 PM by Andy Bennett.)
As a piece of art, a few years back I decided to cast different materials into the shape of a gold bar, title was 'All that glitters'.
I carved a wooden version with suitable logo and 'certification' carved in as markings etc and then made moulds in different materials. The glass version mould was made from silica and took a week to heat and cool down degree by degree in what was our new glass kiln. Luckily we had just had our solar panels installed so I waited for a sunny week.
I also made 2 from metals, one in lead and one in aluminium. The mould was made from a home made green sand mix into a home made wooden box. Both metals were from scrap, the lead came from our roof after an extension and the aluminium from discarded window frames, so not as old as you are thinking of but there were paint contaminants.
I used my forge to melt the scrap so no specific thoughts there other than I made up a solid container to melt the metals in and waited. Skimming off the contaminates was simple, and then just pour into the mould. You have to be quick as it solidifies quickly.
Inspired by my success I also cast a tree stump from the remaining lead I had in stock. That was much more difficult as I had to make a split mould with a couple of risers to let the air out and had to do it in stages as the lead was simply too heavy to pick up too much at a time, but it was really all common sense. That one now sits in the garden and isn't moved very often.
Whilst it didn't concern me you do have to think of shrinkage of c 5-10%.
Lots of caveats regarding fumes and hot metal splashing around etc etc apply.
I carved a wooden version with suitable logo and 'certification' carved in as markings etc and then made moulds in different materials. The glass version mould was made from silica and took a week to heat and cool down degree by degree in what was our new glass kiln. Luckily we had just had our solar panels installed so I waited for a sunny week.
I also made 2 from metals, one in lead and one in aluminium. The mould was made from a home made green sand mix into a home made wooden box. Both metals were from scrap, the lead came from our roof after an extension and the aluminium from discarded window frames, so not as old as you are thinking of but there were paint contaminants.
I used my forge to melt the scrap so no specific thoughts there other than I made up a solid container to melt the metals in and waited. Skimming off the contaminates was simple, and then just pour into the mould. You have to be quick as it solidifies quickly.
Inspired by my success I also cast a tree stump from the remaining lead I had in stock. That was much more difficult as I had to make a split mould with a couple of risers to let the air out and had to do it in stages as the lead was simply too heavy to pick up too much at a time, but it was really all common sense. That one now sits in the garden and isn't moved very often.
Whilst it didn't concern me you do have to think of shrinkage of c 5-10%.
Lots of caveats regarding fumes and hot metal splashing around etc etc apply.
Enjoy yourself, it's later than you think!