Tips when making sinkers

[Gold_Shark]

Hi Guys

I know this has been discussed before, but I need pictures to understand so here goes.

 

Lead too cool: Here is an example of a sinker that was poured and the lead was cooling to fast. Notice the large crack in the top of the sinker all the crevices in the finish. Not only is this an ugly sinker but it is also one that would break on the cast. To correct this I raised the temperature of the lead and the error went away. I also made sure the flow was correct as to lessen the cooling time and produce a better result.
 

Mold too cold: Here is sinker that was poured into a mold that was cold. Notice how the cavity only filled half way and the cavity opening filled. When molds are cold, the heat from the lead is absorbed by the aluminum and causes the lead harden before the cavity can be filled.  This can be eliminated by pouring a few "warm up rounds" with the mold, it would have heated up the mold that it would have probably functioned properly.  The walking sinker and a few of the other smaller sinkers are particularly susceptible to this problem. Always pour a couple trial sinkers to warm the mold before you begin your sinker production.

 

[Kumz]

Thanks for that Gold Shark ...

 

[NetSoGroot]

I was wondering about this phenomena. I baught some bottle nose sinker-moulds from Ajax and almost dunked it in hot water to warm it up. Wonder what will happen when water mixes with lead.................

KABOOOOM PERHAPS??

 

[Pylstert]

Kaboooom indeed and lead splattering all over the place, scary! Make sure your mold and the pot you are melting the lead in is dry!

 

[Dorado75]

I remeber one thing from when i used to make sinkers in Metal work class in school. Never pour molten lead into a mould if there is any water in it...... i found this out the hard way....... i think that there is still lead spatters on the classroom roof 15 years later!!