RCBS Promelt Repair

I posted this on the Shiloh site originally. I had picked up two RCBS Promelts 10 years ago from a friend's estate. The switches were sketchy at the time, so I ordered two replacements from RCBS intending to swap them out when the time came. I got the last two switches they had. That was a decade ago. Last year, the switches finally quit. First one, then the other. So, today I did the repair. Here's my post after getting input from several shooters.

"OK, the Job is done, and I now have 2 working RCBS ProMelt pots up and running.

The switches did have the retaining clips but....the previous owner had affected his own "repair" by holding the switches in the case with silicone calk. Geez, what a mess. It makes sense, my friend was a retired small engine and equipment tech for LA Unified Schools. I would imagine "good enough" was his pragmatic approach. Indeed, it had worked for many years. It's just that the switches themselves crapped out.

So, I drilled out the four rivets holding the sides of the case. I then removed the thermostat control knob. Now, I don't know who made these units for RCBS, but whomever did, was an idiot. The thermostat had a flat side on the knob shaft. The knob has a set screw. Wouldn't you think the set screw would impinge on the flat portion of the shaft thus making a secure connection? Nope, it just pinches the round portion of the shaft. Ugh.

When I opened the case, job one was to hog out all of the silicone calk. Now the case did not want to fully open. So I pried my grandson's wooden slingshot handle in the gap and wedged it open. That permitted me to get some putty knives in there and pry off the caulk. Then I snipped off the tabs top and bottom, that were supposed to snap the switch into place. Once the switch was free, I pulled it through the case exposing the connecting wires. Two were identically colored one was black. I noted which was connected to which numbered spade and used surgical clamps to keep them from retreating into the case. Then one by one, I pried off the connector wires and swapped them over to the new switch. First however, I gave everything a shot of contact cleaner.

I popped the switch into the case and reinstalled the thermostat knob. I turned the pot to its lowest setting as required in the op manual and turned the unit on. It lit! I waited a few minutes and set the pot at 650. After 4-5 minutes I touched the pot and found it to be heating up. Repair complete. That saved me what, $900 for two new pots.

Thank to you guys who gave me cogent input. I appreciate it. Now back to casting! BTW, This weekend I'll be in Castaic CA at a Boy Scout camp teaching Black Powder shooting to a group of 40 scoutmasters. Wish me well and pray for patience and diligence.
Reece"

The repair was simple enough but it was a hassle. Total time for both pots was maybe 45 minutes.

45 minutes is pretty good. I drilled all the rivets out and replaced with self tapping sheet metal screws for future repairs. Replacing the thermostat would be costly to get a direct replacement. In the future I'll replace the lighted switch with a light and bypass the internal thermostat and use my PID for temp control which all my pots do now. I bought my parts from Auberins and switch all my pots to using the same controller.