salt pot parts?

Knifemaker87

Knifemaker87

Joined
Jan 2, 2006
Messages
1,073
hey everybody,
i was thinking about making a high temp salt pot, but i need some help with plans, and parts. i mean after reading the page on Don Fogg's website it seems pretty stright forward, however, i need some help finding and appropriate controller, solinoid, as well as the actual salt to go in the thing.

also, i would assume that the burner is a blown type. recomendations?

does anybody have a good resource for these things?
thanks
~chris
 
Chris,
Darren can sell you the salt, the tube,castable refractory, and a burner.
The basic setup is an upright blown forge with a heavy walled stainless tube in the middle ( with a welded shut bottom). The salt fills the tube. The controller is a PID and the gas is turned on and off by a solenoid valve (controlled by the PID). The thermocouple is in the salt. Use a monel clad 1/4" type K thermocouple. That is about it. All the control stuff can be found on ebay. With your NASA contacts you could probably get the tube turned with 1/4" walls from a solid piece of 4" 312/316,......or just buy one from Darren.
See you Friday AM.
Stacy
 
Knifemaker87 said:
hey everybody,
i was thinking about making a high temp salt pot, but i need some help with plans, and parts. i mean after reading the page on Don Fogg's website it seems pretty stright forward, however, i need some help finding and appropriate controller, solinoid, as well as the actual salt to go in the thing.

also, i would assume that the burner is a blown type. recomendations?

does anybody have a good resource for these things?
thanks
~chris
Click to expand...

Hello Chris,

I am nearing completion of a blown type burner high temp salt pot and vertical forge combination. I've got complete plans drawn up in Solid Edge 2D (free CAD download from --> http://www.plm.automation.siemens.com/en_us/products/velocity/solidedge/free2d/index.shtml )

If you want, send me a PM and I can send you these plans. Gas delivery is set up for two scenarios. 1) Natural gas using normal residential pressure and 2) Propane. These gas delivery methods are not detailed in the plans but I can provide pictures when I'm back in town ~1 week. Forge body is 12" ID X 3/8" tube from scrap yard. Main body is 3' tall with the ability to add a stacked section for sword lengh salt treatment. Two burner ports to allow upper salts to be heated up first, then switch to lower burner once upper salts are at proper heat. Solinoid is an ASCO NC (normally closed) from ebay. PID is from auberins.com. Liner and refactory coating is from Darren Ellis.

This is a work in progress based on a great deal of research. I have very limited space and therefore set out to build one unit that can easily be used as forge then converted to salt as necessary. A false floor shortens up the heated area for forge use and is removed to place long SS salt tube.

Forge portion will be operational in ~2wks with salt portion following sometime after that.

Eric
 
Chris, I would recommend you work with Omega on the controller and thermocouple.

Back when I first built mine, I was having a hard time sourcing parts locally. I ended up going with South Eastern Heaters, and at first was very happy. But later on when I realized they DIDN'T sell me the inconel sheathed thermocouple I had ordered... (the cheap one they sent me was eaten in half in about a month) it took them THREE MONTHS to get me the right one!!!

I gritted my teeth and went through them one more time after that, and it was a similar experience.

I have spoken with engineering techs on the phone at Omega, and they are always very helpful and full of great information.

You can build one a lot cheaper if you buy the components on ebay, but every controller I've seen on ebay was an "as is, no guarantee of function" sale. I wasn't cool with that part, so I went all new parts.

My actual salt pot is self-contained, meaning I can roll it around the shop and outside the door while in use (don't put it in the rain! :eek: ;) lol)

I had a bunch of pics of mine that I took for John Frankl, but I'll be damned if I can find them anymore.

I'll take some more when I get a chance! :)
 
I am very interested in this thread also. Do those of you using salts have two pots going low and high temps simultaneously, or can you quench in oil??

If this is a doable self build, then I'd rather go this route than an oven.
 
I think the standard line here is: Salt is not for everyone. ;)

I LOVE MINE.

I was using a low temp salt to quench from the high temp... but I use so much W2/W1/1095, I prefer Park#50, and I use AAA for my O1 and 52100.

A salt pot is dangerous, but it is also a fantastic tool to have in your shop.

The disadvantage when comparing to an oven, is your temperature range. The salt I have in my set-up starts burning off at like 1800F, so you can't do ss in it. But for everything simple, it works GREAT.

Since mine is in a digitally controlled, blown, vertical forge, I COULD have another salt vessel with a salt suitable for ss. But that's what my Paragon is for. :)
 
I'm not doing anything with stainless. I just want my heat treat process to become as accurate as possible. I'm looking at a paragon also. And I've only recently realized that Olympic Kilns is a mile from my work. I went in there and they have something that would be good. IMO its a little big, so I'll probably spend the extra 200 and get a paragon. But an oven would be yet another draw on my electrical system in the house and I'm thinking about efficiency.

My knives may not be in the same ballpark as yours, or Chris', but I do want them to have the best heat treat I can do. Salt seems like it would make the most efficient use of my time in the shop, which is very limited.

Do you allow the pot to cool with the salts in it, then reheat them when you turn it back on, or would that hurt the salt pot?
 
thanks nick!

i am actually prolly going to work with another guy (on Don fogg's forum) to build two.. one for me, one for him. I was looking and found several omega controllers on ebay, that were new. I have also gotten a thermocouple form omega and they are great! which thermo couple did you buy?

i have to ask, what is the benifit of a blown burner? is there any? i thought that it would just be more of a pain having to deal with the fan too. i have a 1" t-rex burner from Rex Price, that while a venturi burner is KICK BUTT. which would you recomend? cause it would be pretty easy to make a seperate burner for the salt pot.

i really need something to evenly heat treat swords, and so this was kinda the answer.
where did you get your soilenoid? i also think i may have found a couple of omega temp controllers that would work, locally, but they are kinda old.. does that matter?

thanks so much!
~Chris
 
Andy- My knives are in the Winolequa Park ballfield (the tricky namer people added Winlock and Olequa creek) ;) :)

I think you would really like salt. It gives GREAT control over your time and temperature. And contrary to all the fancy hoopla out there, it all comes down to time and temp.

My actual vessel for the salt is 5/16" wall 316 stainless with a cap TIG welded on by Kelly Cupples. I have a long tapered rod (about 7/8" diam on the fat end) that tapers down to a blunt point. I stick it in the salt when I'm done heat-treating. Then the next time I'm going to use the salt, whack that rod with a hammer and pull it out (before putting the vessel into the forge...I actually let the forge run a few minutes before I put the vessel in it) This makes a "chimney" to allow for expansion.

Chris, I did a quick look on ebay and there's lots of good contollers on there now. Most all of them were used back when I was building mine. That route will definitely save you money.

My solenoid is a Dayton General Purpose 120V, two-way, normally closed. Inlet is 1/4" NPT, orifice is 1/8", MOPD : 150 Psig.

I got two on ebay, brand new in the packaging for $15. They're something like $70 at places like Grainger.

I think a venturi burner would work just fine. That T-rex would probably be the cat's pajamas for a salt pot. If you're talking sword length, I'd recommend TWO burners.

You might even want to run the top burner first to make sure you get the upper crust molten... But Kevin could give you a better answer than I can on that :)

I was going to take pics this afternoon, but I seem to have misplaced my memory sticks.
 
I bought mine at a machine shop in the small town I was working in and sent it to Kelly.

I hear Darren Ellis is selling the tubes, but I'm not 100% sure of that :)
 
Thanks for the info!
nick, the burner i have is 1" and pretty darn hot. wud it work to have a n upper and lower port? and maybe throw the burner intot eh upper port at first.. and then close that one off (with some wool or brick) and put the burner at the bottom once it is hot?

i am looking on ebay for both the controller and the solonoid, but i am gonna get the pyrometer direct from omega.

Also, darren IS selling the pipe.. but it is pretty expensive.

i was also wondering, if i make 24" pot.. does that mean i have 24" of heating? or more like 20"? cause that would mean i would want something mroe like a 30" caus ei am not gonna need more than about 24" of heating, max.

thanks!
~chris
 
NickWheeler said:
I think you would really like salt. It gives GREAT control over your time and temperature. And contrary to all the fancy hoopla out there, it all comes down to time and temp.

My actual vessel for the salt is 5/16" wall 316 stainless with a cap TIG welded on by Kelly Cupples. I have a long tapered rod (about 7/8" diam on the fat end) that tapers down to a blunt point. I stick it in the salt when I'm done heat-treating. Then the next time I'm going to use the salt, whack that rod with a hammer and pull it out (before putting the vessel into the forge...I actually let the forge run a few minutes before I put the vessel in it) This makes a "chimney" to allow for expansion.
Click to expand...


Where did you get the rod, which I assume is stainless? A local machine shop taper it for you? I don't have a metal lathe.
 
Hello Chris,

Here is a pic of my gas regulator using an ASCO valve. I have this on another forge but will be using it on my new salt pot/forge combo. It has a bypass with adjustable gas flow (idler) so that the burner will stay lit at a lower temperature when your controller shuts off the gas valve. This eliminates the need for an electronic igniter and makes it much simpler. I've found this to be a very accurate setup when coupled with a good PID and thermocouple. Needle valves are from MSC. Gas input on left, output on right. Eric
 

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Andy- The tapered rod should (and the next will be) stainless, but I used what I had. Which was two ginormous 7/8" X 18" black iron bolts left-over from my great-grandfathers saw mill supplies. I just cut the head off of one and the threads off the other and welded them together at that point.

Then took it to the grinder. If you can contour and smooth out those handles like you do on your knives, I'm sure you can taper a rod easy enough :) A lathe would be good, but my shop is a mix of lightweight engineering and heavyweight red-neck tinkering :D

I HAD a bybass on my salt as it was recommended to me for keeping the fire lit when at lower temps without a spark ignition. BUT! All it did for me was overshoot my target temperature EVERY time. The controller would be telling the solenoid to stay closed, but with that continuous flow of gas, the forge would just keep climbing while the solenoid was completely closed.

I'm glad it has worked for you Eric, but mine just pissed me off so I got rid of the bypass.

I have some parts to install a spark ignitor, but I haven't done it as mine runs smooth as glass from 1400-1700 which is really all the temp range I'm interested in with my salt (for the most part) :)

Here's an old pic I found of when it still had the solenoid bypass.

saltbath-0ec9e.jpg
 
NickWheeler said:
I HAD a bybass on my salt as it was recommended to me for keeping the fire lit when at lower temps without a spark ignition. BUT! All it did for me was overshoot my target temperature EVERY time. The controller would be telling the solenoid to stay closed, but with that continuous flow of gas, the forge would just keep climbing while the solenoid was completely closed.

I'm glad it has worked for you Eric, but mine just pissed me off so I got rid of the bypass.
Click to expand...

Hello Nick,

You bring up a very good point regarding bypass. I found that bypass works very well with a well tuned venturi type burner. One that will easly change from full burn dragon mode, down to a simmer without going out. When I tried my same bypass setup with a blown burner, I had the same results you had. The blown burner does not have the same range of operation that a well tuned verturi has.

As long as you are in the 1400-1700 degree temp range, you do not need an electronic spark ignition to re light the blown burner as the heat is great enough to instantly reignight the gas. A low temp salt pot would need an electronic spark ignition if your setup does not run properly with bypass.

Nice setup Nick!

Eric
 
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