Why do some consider torch annealing superior to salt?

M

Mram10

New member
Salt bath temperatures are much easier to monitor and adjust. I set my pot at 430c (800f) and dip the necks for an 8 count. It is much harder to accurately anneal with map gas at 3000+ deg F. Easy to ruin necks in a milli second of extra heat.
Why haven’t more moved to salt bath annealing?
 
By what I've read on different sites I believe there are quite a few loaders that have taken up the salt bath method.
 
murray brook said:
By what I've read on different sites I believe there are quite a few loaders that have taken up the salt bath method.
Click to expand...

With a good temperature sensor (like a thermocouple), a PID controller (they are very inexpensive now), and a high power switch (often a single transistor) you can set the temperature you want and it will be maintained.

You can get all the parts for less than $50 if you look around.

It also provides better control over a typical lead pot temperature.
They will heat up as fast as they can and then maintain a set temperature with no real attention being paid.

A PID controller is more sophisticated than a typicality bang-bang (on/off) style thermostat.

Even when the switch only allows on/off control of the heater the PID will turn it on and off multiple times per minute to obtain smoother control (variable duty cycle).
 
plans ? i use a lee meltingpot but if there are better systems i like to get the info how to build one /what areyou using for salt mixture ?
 
johan teughels said:
plans ? i use a lee meltingpot but if there are better systems i like to get the info how to build one /what areyou using for salt mixture ?
Click to expand...

IIRC Lee pots have a simple mechanical thermostat.

The heating element is either full on or full off.

This makes the temperature wobble around a set point.
The variation can be larger though.

There are a number if salts that can be used to create a mixture that has a desired melting temp.
Potassium nitrate and sodium nitrate are common.

2 parts potassium to 1 part sodium IIRC.

I still put some Tempilaq on the head as a warning/backup.
Not real high stuff either.
Around 450 F. Low enough that no annealing should occur if you do just hit it.

If that spot melts the case is scrap.

Amazon has some nice 'kits' of a PID controller, a TRIAC to boost output power for the load the pot puts on the system, a heat sink for the TRIAC, a thermocouple in a probe to measure the temperature.
All in a kit around $40. Like this one:
https://www.amazon.com/Inkbird-Thermostat-Temperature-Controller-Thermocouple/dp/B01489AQAW/ref=sr_1_6?crid=2QPSWHBGNN2NT&keywords=pid+controller+kit&qid=1553795537&s=gateway&sprefix=pid+controller+%2Caps%2C151&sr=8-6

A lot of the PID manufacturers have suggested schematics for setup.

For a 120 V load (the pot) parts are pretty common and standardized.

And keep in mind the idea is to partly anneal the brass.
If it goes dead soft in the neck you will have very close to zero neck tension.

An annealing temperature that allows for about a 1 minute dwell at temperature is desirable.

It allows tie for the brass 'crystal' structure to move around without growing excessively large or over annealing.
 
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brickeyee said:
With a good temperature sensor (like a thermocouple), a PID controller (they are very inexpensive now), and a high power switch (often a single transistor) you can set the temperature you want and it will be maintained.

You can get all the parts for less than $50 if you look around.

It also provides better control over a typical lead pot temperature.
They will heat up as fast as they can and then maintain a set temperature with no real attention being paid.

A PID controller is more sophisticated than a typicality bang-bang (on/off) style thermostat.

Even when the switch only allows on/off control of the heater the PID will turn it on and off multiple times per minute to obtain smoother control (variable duty cycle).
Click to expand...

So far all I've used was the Lee pot to control the temp, and it works good, but I can see where the PID system would be a great up-grade. I'll have to look into this.
 
johan teughels said:
the pid you mentioned goes to 400c you use 430c ?
is 430C high enuff ? some info i got heat to 500-550C
Click to expand...

Brass will anneal at 800f(430c) within a few seconds. My necks are usually around .0125” depending on case so it happens quickly. You can go as high as 550c with the salts according to the setup he sells, but I prefer to stay closer to the 800f. I’m sure there are better ways though
 
johan teughels said:
the pid you mentioned goes to 400c you use 430c ?
is 430C high enuff ? some info i got heat to 500-550C
Click to expand...

The thermocouple is rated for 400 C.
It will go further just fine but may not last as long.

The thermocouple junction itslef is good 2,460F.
The wiring and enclosure material around the actual device are what is limiting its range.
 
Can"t buy the kit

Mram10 said:
I bought one of these to save time. It’s proven already.

https://ballisticrecreations.ca/

The temperature doesn’t vary much at all. When doing rum cases, i turn it up 10c+ hotter to account for cooling from cases. Much more temp stable than torches
Click to expand...

I have checked his website for a month. Non for sale. Guess he doesn't make the kits anymore. He claims he does, just keep checking, but no luck.
 
Wouldn’t be hard to make a kit.
Lead pot
Salts
Laser thermometer
Double plate for dipping

Don’t need temp control. It isn’t important. I set mine at 7 on the dial and it keeps it around 430c ish. For bigger cases I start hotter
 
Here’s a basic list
 

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Mram10 said:
Wouldn’t be hard to make a kit.
Lead pot
Salts
Laser thermometer
Double plate for dipping

Don’t need temp control. It isn’t important. I set mine at 7 on the dial and it keeps it around 430c ish. For bigger cases I start hotter
Click to expand...

An on-off (AKA bang-bang control) is not as accurate as the control from a PID.

And you will need to adjust the IR thermometer for the emissivity of the salts.
Other than on a flat black surface they are NOT all that accurate.
Displayed digits is NOT accuracy and resistivity affects the color of the IR spectrum emitted.

The 'progression' of colors for IR operates just like visible and changes with temperature and surface.

A PID controller will turn the heating element off with rapid short pulses based on the rate the temperature is changing and how far it is from the desired set point.

The on off pulses narrow as the temperature approaches the set point.
 
Your setup would be more accurate, but IMO a controller isn’t needed beyond what the pot comes with. An ir thermometer only needs to get you in the 420-550c range. That is close enough to anneal the brass. Without a controller it is far more consistent than torch setups.
 
Mram10 said:
Your setup would be more accurate, but IMO a controller isn’t needed beyond what the pot comes with. An ir thermometer only needs to get you in the 420-550c range. That is close enough to anneal the brass. Without a controller it is far more consistent than torch setups.
Click to expand...

And with a controller is even even more accurate.

Keep in mind the idea is NOT to completely anneal the case neck.

It is to soften it without making it dead soft.

At dead soft you will have ZERO neck tension to hold the bullet.
 
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