How to help making mold

[Crow#21957]

I want to make a mold for a sight base. Question, would silicone work? What would I use for a release agent? I thought I would make a void maybe 1/4 in bigger than the original piece. Fill it with silicone then push the original down into the silicone after coating piece with release agent which I thought Vaseline would l d work. Sm I way off base?

 

[waksupi]

You can do a sand casting by making your pattern from florist foam, leaving a good tab on the blade or base to pour into. Melt your metal, and pour directly into the gate you left on the tab. The foam disappears. Works well for other applications, too.

For a simple sight, it's probably easier and faster to work one out of the material with hacksaw and files.

 

[waarp8nt]

I am no expert, other than casting bullets, I have cast a couple of small parts using lost wax / investment casting. Make a your part of wax, surrounding it in plaster, heating enough to remove the wax and that is your mold. Once casting your part of the desired metal, you simply break the plaster to get to your part.

I have never used silicone rubber as a mold, so I cannot help much with your original question. However, the plaster mold like silicone is pretty cost effective.

 

[Crow#21957]

Thanks both of you. That helps

 

[The Appalachian]

For a simple sight, it's probably easier and faster to work one out of the material with hacksaw and files.

Totally agree.

For the one time thing I can't see messing with a mold that produces something I would have to file and grind on anyway.

Just hack it out of a piece of stock and run with it......

 

[Crow#21957]

I've done one that way. Would sure like to find some more pieces like that one was.

 

[1950DAVE]

And what metal do you propose using? Furnace? I spent about $250 on a furnace to cast several unobtainable parts from aluminum. Steel or even brass is a greater challenge that I am not ready for.

 

[waksupi]

And what metal do you propose using? Furnace? I spent about $250 on a furnace to cast several unobtainable parts from aluminum. Steel or even brass is a greater challenge that I am not ready for.

For small parts, I have used a cast iron dipper and oxy/acy torch for satisfactory work with brass, copper, and pewter. Steel is a whole different ball game.

 

[waksupi]

I've done one that way. Would sure like to find some more pieces like that one was.

What kind of piece are you looking for???