Pinkfoot

Hi Pete, Just wondering if this barrel is still for sale. David

OBSERVATIONS ON USE OF LEE MELTER FOR MOLTEN SALT BATH ANNEALING I began the salt bath journey a couple of months ago and have been perfectly happy with the results. A paper by AMP, manufacturers/marketers of induction annealing equipment for cartridge brass, in which they claimed salt bath annealing simply did not work set me thinking. Having already spoken with an independent annealing company here in the UK who confirmed that flash dipping my case necks in molten salts at 500 deg. C for 5 seconds would do the job and with greater certainty than using flame systems I set to work. The case holder jig is arranged with a bottom plate 1” below the top of the melter pot. It has holes in it for location of the case such that the shoulder is just in the hole. The level of salt is set at 1” below the top of the melter pot so that none of the case body is immersed. I took a number of identical S & B 0.308W cases all of which had been fired five times, neck sized, never heat treated. They were seperated into two random batches. All necks measured 0.334” at case mouth. I took a pair of mole grips and measured the pitch of their adjusting screw. It was 14 threads per inch which equates to 0.0714” per revolution. I felt that this would give me a fine enough control to detect neck deflection in which I was interested. I placed the moles in the vice and carefully closed the jaws on the raw, untreated cases by winding in the adjusting screw . At 3/8 of a turn equivalent to crushing 0.0270” there was complete springback to the original diameter of 0.334” At ½ of a turn equivalent to crushing 0.0358” there was a permanent deflection of 0.002”. When testing cases where the necks had been flash dipped at 500 deg C for 5 seconds the necks were permanently deformed 0.0010” at 3/8 of a turn and 0.004” at ½ a turn. This indicated that the salt bath had certainly reduced stress in the necks. To further test I placed a raw, untreated case neck in in the moles and barelt closed the jaws then continued to tighten until I could go no further using fingers only. I just achieved one full turn. When I repeated this with a flash dipped case the difference was immediately apparent as much less effort was required and I was able to achieve slightly over a turn and a half. I AM HAPPY TO SAY I AM UNABLE TO ACCEPT AMP'S ASSERTION! As an aside to this it is worth mentioning that having achieved 500 deg C (using a PID controller) I checked temperature at varying depths in the salt by raising and lowering the thermocouple. I feel that as long as the thermocouple probe is held off the base of the pot the salt temperature, to all intents and purposes is uniform throughout the bath. The above deliberations took quite a while and I noticed the bath temperature dropping even though the PID was indicating it was in heating mode. It soon transpired that this was as a result of the Lee melter thermostat cutting out on overheat, presumably to to being in a non-vented enclosure adjacent the heating element. This despite turning it up to Max. The best it would achieve was 440 deg. C. I could have simply bypassed the Lee thermostat but being a cautious guy and wanting it to remain as a backstop in case of any failure of the PID I simply adjusted the stat internally by means of minutely reducing the length of the actuating mechanism. All sorted, job done.

Am I correct in thinking you leave the crucible fixing screws out in order to do this. I had thought about polishing the inside of the crucible to facilitate extraction.

Finished my PID controlled, salt bath annealer yesterday and fidled around to get settings. Today set to work and with the temp. At 500 deg. C tempered 40 No. 6BR for 4 seconds and 0 No. .308W for 5 seconds. It all worked a treat and sample seating using the Wilson hand dies felt good wíth 0.001 tension. This is way ahead of the propane torch method! The only mìnor problem was to remove the hardened salt for storage in an airtight container to prevent moisture absorbtion but this was soon solved by turning the heater back on to melt enough salt around the lee crucible to let me dump it out into metal container.

Hi there Pops...... I have left the melter as is, other than replacing the mains plugtop with a variant to fit a variant outlet on the control box. The intention is to find the setting on the melter thermostat which gives circa 600 deg. C. and leave it there. When the PID is turned on power is supplied to the melter just as if there was no PID control. Once the salts reach the temperature set on the PID (around 500 to 550 depending on experiment) it will begin to control the temperature. I feel that if you have concerns as expressed at the rate of bringing the salts up to temperature it would be a simple matter to begin with the melter thermostat low and gradually bring it up until the PID indicated the working temperature and then take the melter stat a smidgeon higher. Does this make sense?

I have just stumbled over this thread and find I'm on a parallel path. Also using the small Lee melter and my shell holder is very similar to those here. As the main reason for going the salt bath route was to improve accuracy and consistency of the reloading process over the gas torch method. I was unhappy at the very much 'hit & miss' (a bit like my shooting!) performance of the Lee temperature control. This inaccuracy negates the rest of the concept. To overcome this I am almost completed the building of a PID temperature controler which is capable of maintaining the salt bath at better than plus or minus one degree C. As a guide for anyone interested, a PID controller is a load switching device to which a Type K thermocouple is connected. The output controls a solid state relay which connects the load to the Lee. Once a required salt bath temperature is set the PID begins the heating process during which it 'learns' to reduce over and undershot temperatures (which Lee type thermostats do badly) until it is able to maintain temprature at very fine limits. This type of accurate control is used by brewers. The total diy cost, including a Lee melter is about £140 I am looking forward to the trial run.