Fixing the Drip-O-matic

[Stephen Cohen]

My Lee 4 20 gave a few drips in its early days, I removed the valve arm assembly and put the valve rod in my drill and lapped it into the valve with valve grinding past. I have had no leaks in the last 5 years and I have put some 400KG of lead through it. I only put clean lead in the pot and do not flux lead while in the pot, I also do not keep casting past about 1inch of lead in bottom of the pot. I have done two of these 4 20 pots and both work just fine, yes they are cheap but with a little care they work just fine. Regards Stephen

[Keith 429421]

Im going to give it another try lapping it. I did use a drill also but I only slightly lapped it Ill give it a good lapping and see what happens.

[Drew P]

I’ve done a LOT of mods on my Lee pot!
-Remade the rod out of spring wire, longer and non threaded
-Lapped it to the seat using a drill
-Gutted electronics and installed PID and ssr inside.
-Thermocouple screwed into bottom of pot, acorn nut on it to seal
-Ditched mold rest and replaces with steel tube
-Ditched slide screws and installed aluminum plate
-Massive steel weight on rod
-Lever with push down fulcrum for raising rod

After all these mods, it’s still drips lol. Not as bad, and the huge benefit of being able to twist the rod freely makes the drip stop. So my normal pour ends with a quick twist on the weight to stop any drips.

My mould rest is sloped slightly away from me so that when I’m filling back to front, that over pours will puddle on their sprew rather than flow forward into the next cav.

I have a splash guard on the PID, and while I’m not sure that it’s safely cool, it’s been holding up fine for many sessions so I guess it’s able to handle the heat well enough.

Gosh, I should make a better pot from scratch and sell them lol!

[Keith 429421]

I worked on the Lee 20-4 pot again today. Removed the valve rod cleaned it up used my turkey stuffing L pin to clean the spout and used a good gob of valve compound to lap the valve and seat with a drill about 30 seconds. Cleaned the spout again with alcohol in the pot getting the valve grinding compound out , drying it well then put the valve rod back in adjusted it and put about 4 pounds of ingots in and the result yes it leaks a drip now and then but only a tolerable bit. I opened and closed the valve rod many times pouring into a RCBS ingot mould and was satisfied. After I turned it off I rotated the valve rod back and forth a little bit and set it down well into the seat . No 4 inch lead icicles after it cooled, so I'll call it a success. I also worked on my 10 lb production pot and lapped it and it was a little better also. So if your having leak problems with a Lee pot , lap the valve rod and pot spout seat with valve grinding compound gently one time if that does not fix it then a bit more cleaning out the lapping compound and make sure the valve linkage handle is not binding on the spout or the screws. Also check to see that the valve rod has the same angle on it all the way around .

[Drew P]

A good way to prevent leaks on pot cool down is to throw a kill shot ingot in (carefully) which will reduce the time to solidify severely.

[Keith 429421]

Welded two 1inch nuts on top of the 20 pound Lee pot after lapping the valve rod and spout the leaks gone I can reach into the hole in the nut to turn the valve rod with a screwdriver to adjust or remove the rod , cast 186 9mm bullets today 1 drop of lead seen on the base, it was indeed a Drip O Matic before

[Tmaloy]

Having the same problem, thinking of putting a hi-temp putty in the screw channel for the threads to have more grip. The bottom screw loosens up about every 50 to 100 uses, really gets aggravating when in a good casting groove and trying to cast a lot of boolits. Just did what you did peened the screw channels to make them catch more metal and hopefully that will hold for a while.

I am getting 4-20 pot soon so please bear with me when I throw this out there, since I don't have it yet but what if you used a 6-32 or 8-32 threaded rod to use as a one piece support for the valve rod assembly? Instead of using the factory threads on the outer shield run the threaded rod top to bottom. Use 1" threaded spacers on the top and bottom of the threaded rod then attach the linkage to it. Run it through the pot and they would be a one piece connection. Place a washer and appropriate screw on each side to keep the valve arm assembly in place. You could probably place a spring in between the arm assembly and the top of the rod with a washer and screw holding it in place and adding downward pressure. Made a rough draft of what I was thinking.