Lee mold problem

[ETG]

Just started casting with a new Lee 45 230gn RN. Everything was going fine for the first hundred or so boolits then the mold started sticking at the rear alignment pins. Let mold cool down and it still hangs. Not cool enough to take it apart yet but can't figure out what would cause it. The mold halfs pivot on the handles easily - it just tries to open like a pair of pliers and not seperate in the middle. Happens even when the molld is empty. Any suggestions?

[docone31]

Wow, it sounds like you have a small piece of lead in one of the alignment areas.
I get them.
You will wait untill the mold is cold to the tough, and look into each area the alignment pin goes. Pick it carefully! Aluminum changes shape easily.
Then, when it is ready to cast again, really heat it up. I close the sprue plate first, then close the mold. This shows me any areas that an issue.
I also soak my molds for two days in mineral spirits before casting for the first time.
You will find it, and it will be easy to fix.

[JSnover]

I solved the same problem by carefully polishing the pins and holes on a Lee six cav. The halves were binding as they expanded and contracted against each other. All it needed was a little relief for the pins. I also learned to let them cool before closing them after the session ended, and to leave them open while I was pre-heating them.
Some things are made just a little too precise. I worked with a retired mold maker (not boolit molds) who told me the holes for the alignment pins should often not be round, especially if the mold will experience severe temperature fluctuations. They actually should be .005" slots (more or less depending on the size and material).

[mooman76]

I solved the same problem by carefully polishing the pins and holes on a Lee six cav. The halves were binding as they expanded and contracted against each other. All it needed was a little relief for the pins. I also learned to let them cool before closing them after the session ended, and to leave them open while I was pre-heating them.
Some things are made just a little too precise. I worked with a retired mold maker (not boolit molds) who told me the holes for the alignment pins should often not be round, especially if the mold will experience severe temperature fluctuations. They actually should be .005" slots (more or less depending on the size and material).

Thanks for the tip. I have a 6x that sticks and I couldn't figure out why. It wasn't too bad but was annoying. Whish I could remember which one.