temp variance on Rcbs pro-melt??

[kevmc]

How "tight" does your RCBS Pro-Melt hold temp (as it comes from factory)??
Are most using a PID with the Pro-melt or not needed????

[bobthenailer]

IMO if you keep the pot from 3/4 to full all the time you wont have any problems ! i usually preheat my ingots on the same hot plate i heat my moulds with . put a 1/4" to 1/2" steel plate on a electric or propane hot plate.

[captaint]

My ProMelt keeps a very constant temp. There are variances when we add lead or whatever, but other than that......... Mike

[AggieEE]

Most bi-metal thermostats have a +/- 5 to 10% range. With a mostly full pot adding a 1 lb bar of lead will not cause a rapid temp change 1/4 full well that's a different story. I think the main cause of large temp varations is adding too much lead at one time. The heater can only chage the temp so fast. In normal use you may not notice a +/-40* change add a lot of lead at once and it may turn into a -100* drop or more. Even a PID had limits as to how fast it can recover from a temp change. If you notice a change in casting just by the normal temp cycling then you might consider a PID.

[BruceB]

In my 'speedcasting' routine, I keep a row of 10.5"-long triangular-section ingots (likely around three pounds each) on the flat top of the furnace. The foremost ones are directly over the melt to preheat. The pot is set at its maximum temperature.

As soon as there's room in the pot, a fresh (hot) ingot is added to keep it FULL. The row of ingots is moved forward and a cold one added to the back of the row to begin heating.

By adding hot ingots, the pot temp seems to drop only about thirty degrees and I do NOT stop casting. The minor temp variation has no effect on the bullet quality.

The Pro-Melt seems admirably suited to my needs....or else *I* have adapted to the Pro-Melt! Whichever the case may be, the furnace is excellent and I don't concern myself with minor variations.

It certainly doesn't need any extra controls such as a PID.... not for my purposes, anyway.

[John Allen]

My RCBS holds steady. I have not had a problem with it. I did just order a pid to make it one less thing to keep an eye on.

[OuchHot!]

Mine ranges plus or minus 25 degrees from "set" when 3/4 full and gets worse when it is below half. I now use a pid which is not really needed for 1-2 cavity steel/iron molds but helps a lot when you go to 4 cavity brass and aluminum molds. My pro-melt is really old but has been like this from day one. I use a fluke to measure the temp.....the old style dial thermometers probably fool most people into thinking the pot is better regulated than it is. For most casting in most alloys, the pid wasn't needed....I did real well without it for a long time.

[gunoil]

i run mine @ 750 800,, does fine.

[detox]

My Pro Melt varies about 50 degrees. The thermostat light will turn ON when temp drops 50 degrees. Then turn OFF when temp reaches 50 more degrees. Continuously turning on and off.

According to my RCBS casting thermometer, actual temp readings are about 50 degrees hotter than what Pro Melt temp dial reads.

I really like my Pro Melt...the best part..."NO" constant dripping spout

[garymcgehee52]

I try to keep my Pro Melt three quarters full. I run it at 750 and add back sprues as I cast. It works fine.

[Jim Flinchbaugh]

I've only had my promelt for a few months now, but I noticed right away, as mentioned above, if you keep it 3/4 full, the
temp stays within 15-20 degrees.