RCBS Pro-Melt Question

[dbarnhart]

I've ordered an RCBS Pro-Melt. For grins I downloaded the instructions from the RCBS website and they say:

"Do not operate the Pro-Melt with less than 1" of alloy in it."

Anyone know why?

[Hickory]

My bet would be that some or part of the heating coil would be above the lead level, and would over heat the steel pot and cause it to burn through.:groner:

[Bradley]

The heating elements go up at least an inch. The furnace is five inches deep. I'd suggest leaving at least two inch of metal in the pot.

[Lloyd Smale]

Mine have been going strong for about 5 years now. I run them till there empty but do fill them before i shut down so that they start with a full pot of lead.

[Lance Boyle]

We could hypothesize this all day long and probably be right on or close.

DB, why not send RCBS an email and ask them why and repost their answer. Would be interesting to see what the engineers think could be an issue.

[RydForLyf]

We could hypothesize this all day long and probably be right on or close.

DB, why not send RCBS an email and ask them why and repost their answer. Would be interesting to see what the engineers think could be an issue.

True, but that would not be nearly as much fun. :-P

[Lance Boyle]

True, but that would not be nearly as much fun. :-P

Oh I hear ya, I almost went back for the edit to say that it's just as interesting to hear fellow members real world experience as well as their theories on the issue.

I imagine RCBS has data, say in the first 2 years they had 85 units returned for burned out elements and they figured out that it was from empty pots or something. So they put in the manual to not let your pot be empty and on. Just thinking out loud here.

[.30/30 Guy]

It's a good thing that I do not have a manual to read. I run mine down to about half an inch on about every session.

[Dale53]

I have two Pro-Melts. I have had one of them for about thirty years. i have cast a couple or three hundred thousand bullets with it. I always run it down to about ½" of lead. After having the manual's recommendations brought to my attention, I won't recommend my practice to anyone else. I might even follow RCBS' lead on this...

Dale53

[jsizemore]

Stick an empty pan on the stove and turn it on HIGH. Look what happens. The pot warps and the empty pot acts as a poor heatsink for all the heat being dumped into it from the heating element. Goes all to hell. That's what COULD happen with the pot being on for a prolonged period.

[bobthenailer]

I try not to let mine get much below 1/3 full .

[C.F.Plinker]

I've not had any problems running mine to empty. I have figured out that you need lead in good contact with the pot walls when you are starting it up. If I have an empty pot I put a few sprues on the bottom and then line the walls of the pot with carefully stacked one pound ingots.

You have 700 watts of heat and it wants to go someplace cooler. If you make a good heat sink within the pot it will go there. Otherwise, it has to go into the rest of the pot (insulation, wiring, housing) and that could overheat those parts of the unit.

[dbarnhart]

I called RCBS and asked them why. I was told that the bottom of the heating coil is about an inch above the bottom of the pot and the temperature sensor is at the bottom of the pot.

[dbarnhart]

A Follow-Up: While the Pro-Melt may draw less than 8 amps, it will trip the GFI on some 15-amp circuits. It does on mine. When plugged into a 20-amp GFI circuit it works fine. Here is another thread about this problem:

http://castboolits.gunloads.com/showthread.php?t=127193

Of course, this is going to force me to do what I've been wanting to do for the last four years: Install a dedicated 20-amp circuit in the garage.

[Dale53]

When I had my utility barn built, I asked for (and got) TWO dedicated and separate 20 amp circuits as I wanted to be able to run TWO Pro Melts if necessary. I have not been sorry (I also ran 220 in and have a 220 volt wall mounted heater and a window air conditioner so that I can cast in most any weather).

Dale53

[40Super]

Thats why I put dual outlets on each side of every window with seperate circuits,a person always runs into issues with needing multiple high juice applications needed at once. and many are wired to a wall mounted switch.

[Oreo]

If you have a 15amp circuit tripping on only 8amps it may be a bad circuit breaker. They do go bad occasionally. Replacing them is a pretty easy job as long as you're careful to keep your fingers & screw drivers away from the bits that are energized and can't be turned off.

[chboats]

You don't need a 20amp circuit to use a 20amp GFI outlet. Just change the GFI outlet. You are not changing the circuit protection just the GFI sensing. The 15 amp GFI outlet is a lot more sensitive to a low level short. I was told by the RCBS rep that this is a common problem with the Pro Melt. Also had the same problem with an electric charcoal starter.

Carl

[dbarnhart]

If you have a 15amp circuit tripping on only 8amps it may be a bad circuit breaker.

The breaker is not tripping. The Ground Fault INterruptor is tripping.


You don't need a 20amp circuit to use a 20amp GFI outlet. Just change the GFI outlet.

Excellent idea!

I still am going to put in a dedicated 20-amp circuit though. The service panel is on the other side of the same wall, so a few dollars worth of stuff and a couple hours of my time should take care of it.

[wallenba]

I've run mine that low while in the 'groove'. When I went to add alloy the whole bottom of the pot was glowing red. I won't do that again. Not enough heat dispertion I guess.

[chboats]

I did burn out the heater in my Pro Melt, but I don't think it was from running it low on lead. It took 25 years and many thousands of pounds of lead. RCBS did a complete rebuilt on the unit for $90. When I got it back the only thing original was the housing and the stand.

Carl

[C.F.Plinker]

I still am going to put in a dedicated 20-amp circuit though. The service panel is on the other side of the same wall, so a few dollars worth of stuff and a couple hours of my time should take care of it.

Check your local building code as well as the National Electric Code. Since the outlet is in your garage you may be required to install either a GFCI breaker in the panel or a GFCI outlet. If this is the only outlet on the circuit it will have to be a 20 amp outlet rather than the usual 15 amp outlet.