When your pot is hot, empty the liquid metal, remove the bracket that holds the stem, and gently tap the top of the pot on your casting bench to clean all the crud out of the pour spout. Clean the tip of the stem. A 1/16" or 5/64" drill bit can be used to open a plugged spout. If you use too large a drill bit, the spout opening will be dangerously too large and your mold will get "flooded" with molten lead. Don't use a 1/8" drill bit.
After the pot has cooled, put a small dab of abrasive paste (valve grinding compound, buffing compound) on the tip of the stem. Put the stem in a variable speed drill, (with the stem bracket off the pot) place the stem in the pour spout, and run the drill at a slow to medium speed for 15 to 20 seconds.
The idea is to polish (or lap) the stem tip and pour spout opening to the same "profile" . After the tip / spout is polished, I polished the shank of the stem to a smooth finish. This stopped/minimized the buildup of crud on the stem that ultimately goes through the spout.
This lapping technique has worked for me on a couple of Lee pots (that ended up in the trash) and my rather expensive RCBS 20# pot that is now over 20 years old and running strong.
I bought a container of valve grinding compound at an auto parts store years ago. It came with 2 lids, one side is fine grit, other side is coarse grit. I think fine grit is #320 and does a great job.
After the pot has cooled, put a small dab of abrasive paste (valve grinding compound, buffing compound) on the tip of the stem. Put the stem in a variable speed drill, (with the stem bracket off the pot) place the stem in the pour spout, and run the drill at a slow to medium speed for 15 to 20 seconds.
The idea is to polish (or lap) the stem tip and pour spout opening to the same "profile" . After the tip / spout is polished, I polished the shank of the stem to a smooth finish. This stopped/minimized the buildup of crud on the stem that ultimately goes through the spout.
This lapping technique has worked for me on a couple of Lee pots (that ended up in the trash) and my rather expensive RCBS 20# pot that is now over 20 years old and running strong.
I bought a container of valve grinding compound at an auto parts store years ago. It came with 2 lids, one side is fine grit, other side is coarse grit. I think fine grit is #320 and does a great job.
