Sand casting my own conchos....

[Chakotay]

I tried my hand at a new skill: sand casting my own conchos. I would say the process was a tad more difficult to learn than I expected. However, after a couple of lightbulb moments (a few actually), I was able to churn them out pretty successfully. 

These are cast in tin, which is easy to melt and work with. I plan on making them in silver eventually.  

 

 

[DieselTech]

Nice work. They look great. 

[dikman]

I follow your you-tube channel so watched it the other day and I was impressed at the fine detail you got, not easy with sand-casting. For tin-casting you might be able to get away with making the mold from silicon, it would allow for repeat casting and give very fine detail.

As an aside after watching your episode about the Vevor press I just had to buy one - I don't really need it (yet) but it's a solid bit of engineering!! Keep the vids coming, they're always good to watch.

[fredk]

I do some casting. I use 'model metal' which is a tin alloy and also pewter, which is a lead and tin alloy. 

For multiple castings I use a heat-proof silicon rubber mould and for one-offs. or two, I did the casting in oil sand

For making conchos I'd use the rubber mould. Its good for about 100 to 150 castings. Less if you allow the metal to get too hot. 

[dikman]

Just checked and the melting point of tin is considerably lower than lead so a silicone mold would be ideal for repeat castings. Won't work with silver though, temp is too high. I believe jewellers use plaster to make their molds but they would likely only be good for a couple of castings at most.

[fredk]

When tin and antimony is added to lead to make pewter it lowers the melting point temperature. For this mix I use a special heat proof silicone rubber to make the mould. The heat proof rubber is meant to be used with pewter casting

Plaster is usually mainly used for a single one-off casting as the heat of the metal cracks the mould and it breaks apart when removing the casting

This is a medieval style belt end I sand cast, then hand painted;

 

[dikman]

Nice job on the buckle fred. I used the silicone for casting lead jig heads for fishing, works well (you need platinum-cure silicone for this). Interestingly, I have some silicone molds I made for casting resin parts for Battlemechs and out of curiosity I tried pouring lead in them and it worked, even though the packaging said nothing about lead use.