Using JB Weld to Customize a Jig Mold

I am experimenting with some jig molds using JB Weld to replicate a few of my favorite jigs. after reading several message boards I am confident that this will work. However, I do have a question. When you place the jig to be replicated into the mold and fill the void with JB Weld, how do you keep the JB Weld from adhering to the jig? in other words how do you keep from "welding" a jig into your mold? I was thinking maybe spraying Pam on the jig or maybe wrapping it in seran wrap? Any suggestions?

You could try petroleum jelly.

I use WD40 when making bondo molds. Might be worth a try with the JB weld.

Andrew

I made a mold with JB weld.... well modified one and the lead doesn't stick to the JB weld because after cured the temperature capabilities of the JB weld far exceed the temp of molten lead! Just be sure to a candle and put some carbon on the mold and go for it. I also use wax to "flux" my lead to remove impurities.

Mold away your safe

[QUOTE=offdtop;480032]I made a mold with JB weld.... well modified one and the lead doesn't stick to the JB weld because after cured the temperature capabilities of the JB weld far exceed the temp of molten lead! Just be sure to a candle and put some carbon on the mold and go for it. I also use wax to "flux" my lead to remove impurities.

Mold away your safe[/QUOTE]

What does putting carbon in the mold do? Ive heard of this before but not sure what the purpose is?

The carbon soot acts as a releasing agent.

Glenn

what kind of jigs are you trying to make?