Lead in plaster.

[Dogfisher1]

Has anyone ever tried to pour lead into a plaster mold? I was thinking about making my own crippled herrings. I'm not intersted in getting set up with real molds. I won't be doing a lot.

[PhilCVG]

YouTube. Based on videos people do it. But Bondo seems to be the preferred way of most. 

[lonellr]

I second PhilCVG. I've made lead molds with Bondo. Works great.

[aae0130]

I carved a shape into a 2x4 and melted lead into it.   I got 3 out f it before it got too bad to get another. 

[Jig Man]

Just be sure that the plaster of paris is set up. If there is any moisture there, things will go very bad, very quickly. 

[woodbutcher]

On 6/1/2018 at 8:33 AM, Jig Man said:

Just be sure that the plaster of paris is set up. If there is any moisture there, things will go very bad, very quickly. 

 

Even after it is completely set up water remains locked in the crystals of the plaster. This water is released when heated and violently so when the plaster is under a pool of molten lead. 

 

Quote

Gypsum plaster, or plaster of Paris, is produced by heating gypsum to about 300 °F (150 °C):[15]

CaSO4·2H2O + heat → CaSO4·0.5H2O + 1.5H2O (released as steam).

When the dry plaster powder is mixed with water, it re-forms into gypsum. The setting of unmodified plaster starts about 10 minutes after mixing and is complete in about 45 minutes; but not fully set for 72 hours.[16] If plaster or gypsum is heated above 266 °F (130 °C), hemihydrate is formed, which will also re-form as gypsum if mixed with water.[17][18]

On heating to 180 °C, the nearly water-free form, called γ-anhydrite (CaSO4·nH2O where n = 0 to 0.05) is produced. γ-Anhydrite reacts slowly with water to return to the dihydrate state, a property exploited in some commercial desiccants. On heating above 250 °C, the completely anhydrous form called β-anhydrite or dead burned plaster is formed...

 

 

[PogyPete]

Agree with Jig Man and Wood Butcher, in my younger days made a mold from plaster and did a pour 2 days later.... was lucky I didn't get burned when it blew up, cracked the mold too. Bondo is not that expensive.