Molten Salt Annealing Rig

[Dunc]

I've got the 'non-salt annealing kit' on the way from Ballistic Recreations. 

Can anyone please suggest which melting pot to go for - the Lee or Lyman?  Obviously I'd want the molten salt mix to be covered by the plate/disc and this appears to be the case with the Lee.  What about the Lyman?  TIA.

[Popsbengo]

1 hour ago, Dunc said:

I've got the 'non-salt annealing kit' on the way from Ballistic Recreations. 

Can anyone please suggest which melting pot to go for - the Lee or Lyman?  Obviously I'd want the molten salt mix to be covered by the plate/disc and this appears to be the case with the Lee.  What about the Lyman?  TIA.

Dunc,

Don't understand the "non-salt annealing kit"?  Do you mean the kit but without the salts provided?  You can get them at APC Pure - see earlier posts.

I believe the Ballistics Creation kit is designed around the Lee pot dimensions.  I'm informed the Lee pot is around 72mm diameter (don't know how deep).  The Lyman pot is 100mm diameter and 70mm deep.  I built my own rig from scratch around a Lyman pot.  My guess is the Ballistics kit is too small for the Lyman.

[Dunc]

16 minutes ago, Popsbengo said:

Dunc,

Don't understand the "non-salt annealing kit"?  Do you mean the kit but without the salts provided?  You can get them at APC Pure - see earlier posts.

I believe the Ballistics Creation kit is designed around the Lee pot dimensions.  I'm informed the Lee pot is around 72mm diameter (don't know how deep).  The Lyman pot is 100mm diameter and 70mm deep.  I built my own rig from scratch around a Lyman pot.  My guess is the Ballistics kit is too small for the Lyman.

Thanks.  And you're right re the non-salt kit.  That's what he calls them, for International sales, as he won't/can't post the salts. 

https://ballisticrecreations.ca/product/no-salt-kit/

No prob re getting the salts from APC Pure and thanks re dimensions of the pots.  

[Pat Allen]

Lee pot is ok but you’ll need to ditch the thermostat and just regulate it with a digital thermo. Dead easy when you get salts from AC pure . Keep temp to around 520c for great results .

[Popsbengo]

4 hours ago, Pat Allen said:

Lee pot is ok but you’ll need to ditch the thermostat and just regulate it with a digital thermo. Dead easy when you get salts from AC pure . Keep temp to around 520c for great results .

If you disconnect the thermostat be damned careful not to walk away, get distracted and let the salts get above 550C, things get seriously hazardous to health.

[Dunc]

Seems like I will be wasting my time trying to molten salt anneal.... 

The people at AMP say they've tested this method of annealing and  - 

Executive summary.

In terms of achieving correctly annealed neck and shoulder hardness of bottle necked cases, 
molten salt bath annealing does not work. Furthermore, even with temperature and time 
adjustments, it cannot work.

https://www.ampannealing.com/articles/52/salt-bath-annealing--does-it-work-/?fbclid=IwAR0onTPh6IRjjIrt0o0qZSYMyGQdg-IitGg3ohRFBz1Iu7O_HMSUIOHiLiM

Summary of molten salt bath annealing:

PROs:

When inserted into the 550°C bath for 5 – 8 seconds, the cases look terrific – just like they have been annealed. 
Even just 2 seconds immersion gives a great looking result. This gives the illusion of annealing.

CONs:

1.       At best, all case necks were only partially annealed. Even using 550°C for 8 seconds, no case necks tested 
annealed softer than 120 HV, which is much harder than desirable.

2.       Even when an insertion time of 20 seconds @ 550°C was used, necks were not correctly annealed. The case 
bodies, however, were over-annealed.

3.       The process is HAZARDOUS. For those determined to try it, the following articles should be read thoroughly. 
This link is an industry guide to the safe use of molten salt baths. It doesn’t even contemplate domestic use. 

 What is the point of taking on all that risk, when the results are so poor? There are several ways to achieve correct 
annealing. Molten salt bath "annealing” isn’t one of them. For those reloaders considering getting started on annealing, 
and who are on a budget, we would recommend a gas flame-based option.

 

[Popsbengo]

Let me guess, they are peddling an alternative system?  For fork sake, it's biased propaganda peddling as information.

Bullshit baffles brains.  Molten salt annealing and heat treatment is a tried and tested system common in engineering and used for the last 150 years.

In the end, just do what you feel's right.

[Dunc]

5 minutes ago, Popsbengo said:

Let me guess, they are peddling an alternative system? .......

Surely not!!!!    

Will give the article a better read after the weekend when I've a bit more time.  And make up my mind then  

[Popsbengo]

To my mind the best test is:

1) does your brass last - ie, is cracking prevented/reduced?

2) do you get good ballistic performance from your brass?  Group size etc?

If the answer is yes to both then one has achieved ones goal.  The effects they (Amp) report may be well founded but are they over-egging the issue?

 

[Dunc]

15 minutes ago, Popsbengo said:

 

If the answer is yes to both then one has achieved ones goal.  The effects they (Amp) report may be well founded but are they over-egging the issue?

 

I agree on all your points and I'm looking forward to getting my analytical hat on after the weekend to fully review their article, got competitions all weekend.  I certainly do have my suspicions...

[Re-Pete]

My trial run with molten salt definitely softened the neck/shoulder area. The difference was easily felt simply by squashing the neck before and after with a pair of long nosed pliers. (a dud case........)

As for annealing too much of the case body, jury is still out.............

Pete

[Malinois]

Definitely had an effect on lowering my ES to say it does nothing. 

[Popsbengo]

I wonder if the subject is somewhat confused by the loose use of 'anneal' as the process that's being used.

Annealing is modifying the grain structure and the homogeneous nature of the alloy materials.  Stress relieving is the reduction of internal stresses built up by cold working. Both are time/temperature related for brass alloys.

Is what we are trying to achieve actually stress relief ?  I'm not sure that Vickers hardness testing (as used by Amp) is actually wholly relevant to the needs of the reloader.

Any metallurgists out there to enlighten me?

[Lukas_K]

I´ve read the "paper" carefully, I feel it´s like Churchill´s statistics... you make them what you want.

From purely technical standpoint, I don´t believe hardness is necessarily representative of material ductility/flexibility. There are lot of materials that are hard and brittle, then those hard and flexible and anything in between. The strength with which the case neck holds the bullet is a function of the material springiness (bullet expands the neck and the neck spring-back is what really does the work).

As far as reloading application, I´d see more value in a test that would pit non-annealed cases against cases annealed by different methods, and measure bullet seating force (not for absolute numbers, but for case-to-case standard deviation) and chrono the resulting reloads. That, side to side, would have practical value.

As for my own experience, I noticed improvement in both velocity SD and case longevity when I started annealing by gas flame a few years back. Thus, I decided annealing has value, because I saw the difference comparing to repetitive reloading of non-annealed brass. Last season, I turned to salt bath simply because it´s superflexible as to the case type - you don´t need special case carriers for different sizes etc. I can now say that my results haven´t changed a bit, which to me translates to salt bath working to the same practical result as the flame I used before.

[Popsbengo]

1 hour ago, Lukas_K said:

I´ve read the "paper" carefully, I feel it´s like Churchill´s statistics... you make them what you want.

From purely technical standpoint, I don´t believe hardness is necessarily representative of material ductility/flexibility. There are lot of materials that are hard and brittle, then those hard and flexible and anything in between. The strength with which the case neck holds the bullet is a function of the material springiness (bullet expands the neck and the neck spring-back is what really does the work).

As far as reloading application, I´d see more value in a test that would pit non-annealed cases against cases annealed by different methods, and measure bullet seating force (not for absolute numbers, but for case-to-case standard deviation) and chrono the resulting reloads. That, side to side, would have practical value.

As for my own experience, I noticed improvement in both velocity SD and case longevity when I started annealing by gas flame a few years back. Thus, I decided annealing has value, because I saw the difference comparing to repetitive reloading of non-annealed brass. Last season, I turned to salt bath simply because it´s superflexible as to the case type - you don´t need special case carriers for different sizes etc. I can now say that my results haven´t changed a bit, which to me translates to salt bath working to the same practical result as the flame I used before.

Spot on Lukas, I agree fully.  The only sensible tests are case life and SD performance.   I'm sure AMP make a fine product but there seems to be an awful lot of BSBB in their article.  I especially liked their "warning" about over-annealing the case head - for sure they are correct about not weakening the case but why on earth would anyone leave a case in the salt bath so long as to bugger it up just to achieve their "recommended hardness" !!

[Pinkfoot]

On 5/21/2019 at 5:36 PM, Popsbengo said:

Spot on Lukas, I agree fully.  The only sensible tests are case life and SD performance.   I'm sure AMP make a fine product but there seems to be an awful lot of BSBB in their article.  I especially liked their "warning" about over-annealing the case head - for sure they are correct about not weakening the case but why on earth would anyone leave a case in the salt bath so long as to bugger it up just to achieve their "recommended hardness" !!

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.

[Re-Pete]

I came to the same conclusion, albeit by a slightly more Heath Robinson approach involving a pair of long nosed pliers and a couple of burnt fingers.............

The Lyman melter got the salt up to 550C in around 25-30 mins at full throttle, but with the knob at 2/3rds of it's travel, the temp  swing between power on and power off was over 50C.

Needs more work.................I guess that when the melter is used for lead, it's nowhere near as critical.

Pete

[Popsbengo]

2 hours ago, Re-Pete said:

I came to the same conclusion, albeit by a slightly more Heath Robinson approach involving a pair of long nosed pliers and a couple of burnt fingers.............

The Lyman melter got the salt up to 550C in around 25-30 mins at full throttle, but with the knob at 2/3rds of it's travel, the temp  swing between power on and power off was over 50C.

Needs more work.................I guess that when the melter is used for lead, it's nowhere near as critical.

Pete

For the small batch quantities I anneal, I keep an eye on the temperature and turn the 'stat up/down as required to maintain temperature on my Lyman pot.  I don't find that the temperature varies much to be honest even when doing a 100 off .338 cases.  I was going to make a PID controller but I'm not sure it's worth the effort.

I did a comparison with calibrated pliers (😉) too, pretty much got the results as you and Pinkfoot report and easily as good as my gas-flame rotary annealing rig but without the faffing about getting the flame "just right" with Tempilaq.

[Re-Pete]

I flame mine in the dark so that I can see the actual colour. Gave up messing about with tempilaq..............the gas flame varies as the gun heats up, so keeping an eye on the colour and adjusting the exposure time works best for me. I'm on a batch of 6.5x47 cases that are still going strong after 22 firings, annealing after every 5 or 6.

Pete

[Dunc]

On 2/10/2019 at 4:29 PM, Popsbengo said:

I use 50% potassium nitrate;  45% sodium nitrite;  5% sodium nitrate -  by weight.  At 500C there is no fuming I can detect.   Be careful about going over 550C things start to get 'exciting'.

I accept no liability for the correct mixture🤔

Anyone else had any issues with buying these salts from APC Pure?  I've just put an order in for these and I've had an email back saying they won't supply sodium nitrite unless I'm a limited company  and a follow up phone call to them didn't help - 

Quote

Restricted Chemical 47999 Sodium Nitrite

Thank you for your recent enquiry.

 Please note the recent new legislation that came into effect under new rules issued by the UK Government on 2^nd September 2014.

 We can now only supply to Limited companies, Partnerships, Sole Traders, Trading Businesses  or to persons who are in possession of a home office license to receive this product.

 We would also need to know the application for which you intend to use this product.

 If you do not meet the criteria we will be unable to proceed with your order.

 If you feel you meet the criteria listed above and are OVER 21 YEARS OF AGE, please complete the attached form and return it to us for approval, please also supply Photographic Identification (Driving Licence/Passport) and proof of address.

PS - I see it's apparently easily available from eBay and since it's only a minor 'ingredient' to the mix, I don't need much but still curious as to if anyone else had an issue with being supplied by APC Pure.

[Popsbengo]

47 minutes ago, Dunc said:

Anyone else had any issues with buying these salts from APC Pure?  I've just put an order in for these and I've had an email back saying they won't supply sodium nitrite unless I'm a limited company  and a follow up phone call to them didn't help - 

PS - I see it's apparently easily available from eBay and since it's only a minor 'ingredient' to the mix, I don't need much but still curious as to if anyone else had an issue with being supplied by APC Pure.

Sodium NITRITE It's not a minor ingredient, it's 45%.   No, no problem and I've ordered twice and I'm a private individual. 

[Dunc]

3 minutes ago, Popsbengo said:

Sodium NITRITE It's not a minor ingredient, it's 45%.   No, no problem and I've ordered twice and I'm a private individual. 

45% of course, sodium nitrate is 5%.
Wonder if anyone else was 'refused'.  They did send me a form to complete but that asks me my company details.. 

[nicklock]

Their actions are incorrect under the relevant legislation (The Poisons Act 1972, as Amended - which you can read here.)

All 3 chemicals are only Scheduled (Schedule 1A parts 3 and 4)  as "Reportable Substances", *not* "Regulated Substances" (both terms defined in Section 2) - and do not require a license to buy or possess (offenses only relate to Regulated Substances, see Sections 3, 3A and 3B). 'Possess' is an important one, rest easy anyone who's already got hold of some!

They are not even compelled to "report" the transaction either, as Section 3C Clauses 1 to 4 clearly show that simple questions could be used to remove "reasonable grounds for believing the transaction to be suspicious".

/sigh

If I were to guess, it's a toss-up between them getting some new stock in and the admin staff ticking the wrong box on the database (so you'll get "computer says no" as a response) - or that they've decided to gold-plate the legislation because they can't be bothered with the effort of dealing with Joe Public versus the larger/easier revenues from industry (so you'll get a teeth sucking 'jobsworth' response).

If they'll still sell you the other 2 parts, despite them all being in the Reportable lists, then just nod and smile and get it from eBay?

[Dunc]

30 minutes ago, nicklock said:

Their actions are incorrect under the relevant legislation (The Poisons Act 1972, as Amended - which you can read here.)

All 3 chemicals are only Scheduled (Schedule 1A parts 3 and 4)  as "Reportable Substances", *not* "Regulated Substances" (both terms defined in Section 2) - and do not require a license to buy or possess (offenses only relate to Regulated Substances, see Sections 3, 3A and 3B). 'Possess' is an important one, rest easy anyone who's already got hold of some!

They are not even compelled to "report" the transaction either, as Section 3C Clauses 1 to 4 clearly show that simple questions could be used to remove "reasonable grounds for believing the transaction to be suspicious".

/sigh

If I were to guess, it's a toss-up between them getting some new stock in and the admin staff ticking the wrong box on the database (so you'll get "computer says no" as a response) - or that they've decided to gold-plate the legislation because they can't be bothered with the effort of dealing with Joe Public versus the larger/easier revenues from industry (so you'll get a teeth sucking 'jobsworth' response).

If they'll still sell you the other 2 parts, despite them all being in the Reportable lists, then just nod and smile and get it from eBay?

Thanks for that, very useful to know. Dude did say to me that they tend to deal only with companies or words to that effect. They've taken the sodium nitrite off my order and are sending me the rest.  eBay, here I come!

[Dunc]

Ha-ha.  I see APC Pure sell sodium nitrite freely on eBay....   132715337108     

Albeit somewhat more expensive than on their website.