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Popsbengo

Molten Salt Annealing Rig

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Well...with a bit of to’ing and fro’ing getting the PID to communicate properly with the SSR, it’s finally finished and I used it in earnest for the first time this morning for another batch of .20Prac cases.

Last step (which took a couple of timewasting dead ends before I bought what I should’ve done in the first place) was to fit an led to come on when the PID switches on the relay so I know the output socket is powered. 

Adjusting the deck height in the caseholder worked until the heat got too hot and galled the threads and I annealed to just over onto the shoulders. 

I was quite impressed the PID didn’t overshoot by more than a degree...doing over a hundred cases, the temperature only dropped by a degree so that’s a pretty tight range. Bearing in mind Pinkfoots observations above and in his subsequent email, I’ll anneal the next lot at 500c.

What you can’t see clearly from the photo is the .243 case neck keeping the 6mm probe off the bottom of the pot and any possibility of a false reading.

Just remains to say many thanks to everyone’s input and assistance...invaluable!

Cheers

Fizz

E6CD6926-A837-4DED-9D78-10C5E7C53016.jpeg

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Well done, looking good.  For the time being I'm providing PID duties with my No.1 eyeball (cheapskate me!).

It'll be good to hear your experience regarding case life and performance down the line.

I've found using very hot water to dump the cases into is very effective at removing any salt carryover (I use a large bucket, full up, and kept well away from the salt bath).

 

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How difficult was it to make the PID? I'm using the Lyman pot and it really does take some heating up. The onboard stat seriously needs a bypass.

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hmmmm, having problems trying to source Sodium NItrite.

APC appears to sell the Sodium Nitrate and Pottasium NItrate ok.

Any pointers of where to try and obtain the Sodium Nitrite?

All the best

G

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I bought it from APC in February last year.... just been across and logged in to search for it but with no joy ☹️ Someone mentioned in a post a few months ago that APC were selling it through their ebay shop but that didn’t bring anything up either. 
 

Have you tried ringing them? 
 

cheers

Fizz

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1 minute ago, fizzbangwhallop said:

I bought it from APC in February last year.... just been across and logged in to search for it but with no joy ☹️ Someone mentioned in a post a few months ago that APC were selling it through their ebay shop but that didn’t bring anything up either. 
 

Have you tried ringing them? 
 

cheers

Fizz

Hi Fizz,

I will give them a call tomorrow. I found the only other option on eBay here:  https://www.ebay.co.uk/itm/250g-Pure-99-Nitrite-Salt-Food-Grade-For-Meat-Curing-E250/293583361131?hash=item445aee946b:g:yGYAAOSwJ65ewaoK

Hmmmm

Cheers

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On 6/14/2019 at 7:37 PM, Malinois said:

How difficult was it to make the PID? I'm using the Lyman pot and it really does take some heating up. The onboard stat seriously needs a bypass.

PID's are pretty simple to set up, a single off the shelf unit and then buy a suitable thermocouple and solid state relay

I put one together years ago for my bullet casting setup, combined with a heater plate for ready use ingots keeps the mix very temp stable, not sure if I have the circuit drawing still, but look online, probably find details on the web : thus:  https://www.castbulletassoc.org/forum/thread/pid-theromocoupler-control/

Latest Lyman pots come with PID in them:  https://www.lymanproducts.com/brands/lyman/bullet-casting/casting-furnaces/mag-25-digital-melting-furnace

pid.thumb.jpg.9c2f2cb01ce97f3b119537d42c756d24.jpg

As to 'bypassing' the existing stat, why do that, just set the existing stat above your target temp, it is then a backup if your PID goes boobs-up, just a suggestion.

Re AMP's claims - yes they are a small company pushing their gear - what would you expect them to say 'our kit is expensive rubbish' ? 😏

Simple questions to ask:

Does it make a difference - 'yes' from my own findings

Does it matter how you do it - 'no' use whatever works for you.

Tried flames by different methods, years ago simple holder+plastacene in the end of a battery drill in a dark room - worked but what faff. Then tried turntable flame - much better, but setup,plus open flames, need to sit by it did not 'do it' for me.

Salt baths - had looked previously but just seeing the posts here confirmed my original analysis, chemicals at temperature, cannot leave it, time to get going etc., again not for my needs.

So went for the easy option, yes it costs but it ticks all the boxes for me being:

  • Instant setup - from walking in the workshop to annealing <2 minutes
  • Can do small batches - if I've 20 cases to do no issues
  • Change of cartridge, from last annealed case to next < 1 minute
  • No flames, hot chemicals etc.etc.
  • Can walk away at any point, have food and walk back again picking up exactly where I left off (without wife keep shouting 'it's on the table' )
  • but above all - consistent results = I'm a happy bunny

Many a mouse trap out there - just pick yours 😉

T

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Hi All,

Just a quick update for anyone in the future struggling for Sodium Nitrite, I was able to get all three salts from APCPure. Just need to contact them by phone informing them of your request, then email them directly, they then supply a form to be filled out confirming usage which then gets vetted internally for approval.

 It seems a bit long-winded but actually it wasn't and they were very helpful. Salts and Lyman pot on their way!!  Happy days. 😊 Now for a full-length welders apron with sleeves and full face mask (risk-taking = firmly in the minus numbers).

G

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1 hour ago, gruntus said:

Hi All,

Just a quick update for anyone in the future struggling for Sodium Nitrite, I was able to get all three salts from APCPure. Just need to contact them by phone informing them of your request, then email them directly, they then supply a form to be filled out confirming usage which then gets vetted internally for approval.

 It seems a bit long-winded but actually it wasn't and they were very helpful. Salts and Lyman pot on their way!!  Happy days. 😊 Now for a full-length welders apron with sleeves and full face mask (risk-taking = firmly in the minus numbers).

G

I assume you have a thermocouple temperature sensor.  Temperature is critical for process and for safety.

Once the salts are mixed and on the first melt you will get a scum floating on top of the salts as they reach higher temperatures - don't worry they go away and from then on it's reasonably clean.  The occasional top-up of salts is required to replace carry-over losses.

The salt, when cooled turns, into a solid puck so don't forget to remove the jig when it's all cooled down a bit.  I put the cold puck into a ziplock bag and into a sealed plastic container as the salts are quite hygroscopic.  To aid the removal of the puck I discarded the three screws holding the pot into the heater so I could lift it out and bang it on a wooden block to remove the cold puck.  For the next melt I just pop the puck back into the pot and wait until it melts so I can then replace the jig while the temperature isn't too high for safety.

If you have any issues I'll be happy to help if I can.

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17 hours ago, Popsbengo said:

I assume you have a thermocouple temperature sensor.  Temperature is critical for process and for safety.

Once the salts are mixed and on the first melt you will get a scum floating on top of the salts as they reach higher temperatures - don't worry they go away and from then on it's reasonably clean.  The occasional top-up of salts is required to replace carry-over losses.

The salt, when cooled turns, into a solid puck so don't forget to remove the jig when it's all cooled down a bit.  I put the cold puck into a ziplock bag and into a sealed plastic container as the salts are quite hygroscopic.  To aid the removal of the puck I discarded the three screws holding the pot into the heater so I could lift it out and bang it on a wooden block to remove the cold puck.  For the next melt I just pop the puck back into the pot and wait until it melts so I can then replace the jig while the temperature isn't too high for safety.

If you have any issues I'll be happy to help if I can.

Hi PospsB,

Thanks for the offer of assistance, I will certainly take you up on it! 😉

I still have to obtain a temp sensor, I had in mind a K Type digital meter the same as yours from RS. With regard to a thermocouple (going by the RS web site) I am assuming an enclosed probe will be required for the immersion in a molten liquid of course (similar to that in the link below). 

There's a vast choice available, what max temp would you suggest? (Obviously, the desired range of circa 500°C is needed for annealing and would assume +100 to 200 minimum?) .

RS Thermocouple

Thanks again.  

G

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15 minutes ago, gruntus said:

Hi PospsB,

Thanks for the offer of assistance, I will certainly take you up on it! 😉

I still have to obtain a temp sensor, I had in mind a K Type digital meter the same as yours from RS. With regard to a thermocouple (going by the RS web site) I am assuming an enclosed probe will be required for the immersion in a molten liquid of course (similar to that in the link below). 

There's a vast choice available, what max temp would you suggest? (Obviously, the desired range of circa 500°C is needed for annealing and would assume +100 to 200 minimum?) .

RS Thermocouple

Thanks again.  

G

Hi G

The thermocouple you link to is not suitable - it's rated to 200C only.  The Pro Air part: 342-889 is good, it can be bent into shape also.  I drilled a hole at the back of my fixture so the probe can easily sit in the pot at all times.  The digital thermometer RS Pro RS41 part: 123-1940 is what I have.

I'd avoid K Type beads and eBay specials as many are rated to 400C only.

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Hi All,

Thought I would provide my set up for any future annealers.

This setup is very simple and only needs a drill (all in stainless steel so pay attention to pops warnings about sharp tools and work hardening!), 1 x 125mm disk, 2 x 100mm disks, 2x 50mm M6 bolts and plain nuts. All that needs to be done is drilling 1 x large hole for your calibre and three smaller m6 clearance holes for the bolts and temp probe. The top and middle plates need all holes drilled identically, only 2 x bolt holes required for the bottom plate.

Tip for those with limited tooling (pillar drill in my case)), I centre popped all holes on the large plate, then drilled all three centres first, placed a single bolt through and "locked off" all three plates with a nut then drilled the remainder all in one go to ensure the hole centres were all aligned.

It "hangs" nicely on the top of the Lyman pot (I removed the retaining screws of the pot for ease of removing the puck) and the two lower disks sit in the pot and keep things nice and steady.

The only observation I have is that the centre plate has slightly distorted but its only really there to keep the probe and the case centred in the hole properly during annealing. 

During annealing, I have the large hole to the right as per the first pic with the hole for the temp probe at the rear. 

All of this has been created standing on the giant shoulders of everyone else's input on this thread so thanks to everyone's input and also a big thanks to Pops for his additional help and guidance over private messaging.

Hope this helps someone in the future.🙂

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Nice and simple.   I found that slightly dishing the top plate helps with minimising molten salt building up from drips.

Happy to have helped

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Looking good Gruntus 👍

I did a 100 batch of .243 cases a couple of months ago at two at a time and it didn’t make any noticeable difference to the temperature maintenance.... and of course it halved the time over doing one case at a time (why didn’t I think of that before! 🤪)

The other thing that I tried and certainly helped, was taping a piece of rainwater downpipe to the edge of the bench with the bottom end just under the surface of the 2l jug of hot water on the floor.
I did angle it away slightly so in the remote chance of any splashes making over a yard of flight went away from the salt pot. 
And it saved a lot of salty watery mess on the floor around the jug. 
 

cheers

fizz

😎

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Hi, after some good old honest advice, Dose this technique work? I’ve got the AMP report casting doubts over it, in my mind. You lot have been doing it for a while now, are you seeing longer case life? 

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2 hours ago, Matt B said:

Hi, after some good old honest advice, Dose this technique work? I’ve got the AMP report casting doubts over it, in my mind. You lot have been doing it for a while now, are you seeing longer case life? 

Yes it works.  I have no axe to grind as I'm a home workshop warrior not a corporation,  AMP are selling a product for mega dosh - you'd expect them to make an argument against anything other than their product.  I think too much snake oil in their advertising.

I don't doubt their system is very tune-able but I can't see that it makes any real world difference.  I can vary temperature and time infinitely so I think that combo will do.

I don't think I've done enough cycles to give an honest appraisal of case life.  My only scrapped off cases (.308) were due to slack primers not case neck problems

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Thanks for getting back, I was taking the AMP report with a pinch of salt 🤣 since they have a vested interest, if you have had good real world results with it then I’ll give it a go.

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1 hour ago, Matt B said:

Thanks for getting back, I was taking the AMP report with a pinch of salt 🤣 since they have a vested interest, if you have had good real world results with it then I’ll give it a go.

If I can help along the way don't hesitate to ask

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40 minutes ago, KatoomDownUnder said:

Quick question, other than to cool your brass down quickly why are you quenching your annealed brass?

Just to cool down quickly and stop the heat running further down the case.  It's also a rinse to remove any carry-over salts.

I use hot water as it removes salts better 

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On 10/9/2020 at 7:08 PM, Popsbengo said:

Just to cool down quickly and stop the heat running further down the case.  It's also a rinse to remove any carry-over salts.

I use hot water as it removes salts better 

Ahhh yep makes sense.

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As a quick, comparative update; I moved from salt bath to induction earlier this year.

I used salt bath for good 2 years for several calibers from 6Br up to 338improved, in total close to 6000 reloads/shots fired. Had convincing results with salt-bath, both from target results and ES/SD measured at different times of season with more and more loadings on the cases. If my salt-bath annealed cases failed, it was by loosening primer pockets, never a neck split. I salt-bath-annealed brass for ackley fireforming as well and lost none in the processing of 200+ 338LM cases.

The recordkeeping gives a base of comparison for the induction results now and all I can say is - they are the same. While the only process changed in the reloading cycle was the switch from salt batch to induction (at the same point of the reloading cycle), both the target results of proven loads and measured velocities remain the same. For me, that additionally confirms that the salt works just fine. 

The advantage of the induction is mostly time saving, as there is no prep/cleanup, you can switch between calibers/case sizes immediately and the time per case is cut approximately in half as well.

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4 minutes ago, Lukas_K said:

As a quick, comparative update; I moved from salt bath to induction earlier this year.

I used salt bath for good 2 years for several calibers from 6Br up to 338improved, in total close to 6000 reloads/shots fired. Had convincing results with salt-bath, both from target results and ES/SD measured at different times of season with more and more loadings on the cases. If my salt-bath annealed cases failed, it was by loosening primer pockets, never a neck split. I salt-bath-annealed brass for ackley fireforming as well and lost none in the processing of 200+ 338LM cases.

The recordkeeping gives a base of comparison for the induction results now and all I can say is - they are the same. While the only process changed in the reloading cycle was the switch from salt batch to induction (at the same point of the reloading cycle), both the target results of proven loads and measured velocities remain the same. For me, that additionally confirms that the salt works just fine. 

The advantage of the induction is mostly time saving, as there is no prep/cleanup, you can switch between calibers/case sizes immediately and the time per case is cut approximately in half as well.

That's good info and as valid a comparison as we're likely to see.  I was sceptical of the sales bull shine associated with AMP induction however it's certainly a very good method - if a tad more expensive than the approx. £100 it cost me to set up the salt rig 😉

IMO Both methods are superior to gas flame in that they are controllable to a fine degree and remain stable through the process cycle.

I think it's worth noting that the induction system is also inherently less dangerous - 500deg molten, strongly oxidising, salts are not to be treated lightly.  That said, anyone practicing reloading should have the capacity and good sense to handle the risk.

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