PDA

View Full Version : Lead leakage


airone46
10-25-2018, 06:28 AM
has it ever occurred to you a lead leak between sprue and mold?
[IMG] http://i68.tinypic.com/8yawb6.jpg [/ IMG]

(obviously the screw of the sprue was tight!)

I solved the problem by smoothing the surface of the mold.
lightman
10-25-2018, 09:16 AM
It happens if the sprue plate gets bent too. I've fixed a few.
waksupi
10-25-2018, 09:30 AM
You can also get them TOO tight.
mdi
10-25-2018, 12:09 PM
Yep, warped, loose and too tight. I have removed the sprue plate and polished the underside on a piece of fine emery cloth on a flat surface. This will show if the plate is warped. If the hold down screw is too tight it might raise the plate on the end away from the screw. Too loose is obvious. I have squared up the top of a couple molds with emery cloth on a flat surface and carefully rubbing the mold across the emery. Fine emery and oil will leave a polished surface, but be careful, it's easy to screw up a mold...
beagle
10-25-2018, 12:48 PM
Normally the sprue plate is warped caused by lead on top of the mould or bottom of the plate. Clean this off and coat the bottom and top of mould with graphite or spray moly. With sprue plate tight and operating smoothly, cast bullets for a while, watching for lead build up and with the sprue plate getting up to casting temperature, they normally flatten out. I also have a lump of beeswax on the bench and if I see this problem coming on, I rub it along the sprue plate/mould junction just enough to lubricate the edge of the junction and in several casts the problem goes away./beagle
airone46
10-25-2018, 01:25 PM
I have:
1 RCBS Mold
2 Lyman Molds
6 Lee Molds
I hope I have not forgotten other molds!

Cavity? from 1 to 6 cavities! I know how to use a mold after 60 years! It was just a small construction defect!
I needed that mold urgently and took it to a precision grinding workshop, repaired it, and then it worked perfectly (but it does bullets of inferior weight and without g.c.).
I paid the repair, but I have NEVER had the faulty mold replacement!
The reason? I tampered with a mold that did not work before and after it works!
A CRAZY explanation!