The Lee 20# Bottom Pour Melter is the BOMB! I use mine to cast bullets and to make ingots from raw WheelWeights. Easy to scoop the dross and clips from the wide mouth. Flux often and generously...I use leftover candle wax, chopped into corn niblet sized pellets. Stir carefully while fluxing to get all the clip/trash/ash to float.
What I like about using the bottom pour valve, rather than ladling, the lead out of the bottom spout is cleaner, because any dross/ash/dirt float on lead. So if you wanted to use a ladle, you need to keep the top of the melt clean by constant fluxing and skimming...not a bad thing but it takes more than I care to put into it.
Yeah the bottom valve leaks sometimes. Have a screwdriver handy to turn the screw on top of the needle valve, just to loosen some dirt that may have wedged intself in the valve body below. Should take care of the leak.
You can also try screwing down the needle valve an eight of a turn at a time, in case it has worn a bit and doesn't drop down enough to seal.
Anyways, if and when it leaks, it is an easy twist/turn of the screw....no biggie....never bothered me. Hardly happens anyway in the three years casting.
If the valve stops pouring, it could be your melt got too cold. Your thermostat may be set a little too cold, or you are putting in cold ingots faster than the pot and heat up to melting temp. My thermostant is set between 6 and 7 when I am casting fast contiuously and in the groove. I end up with frosty bullets this way.
If I cast slower, I just keep the thermostat at 5.5 and wait for the melt to heat up before casting. Bullets are shinier this way, but then paper targets don't care about bullet finish.
I preheat ingots by placing them on the top lip of the pot about 10 minutes.
They will melt easier and not cool down the melt sufficiently to solidify/cool it down. Place a cold ingot on there, as soon as you drop a preheated ingot.