Home-Made casting pots

[MakeMineA10mm]

Anyone ever tried building their own bottom-pour casting furnace?

I'd like to combine several ideas I've seen on commercial pots, plus throw in a few of my own ideas. I'm wondering about cost.

I was about two months away from buying a Magma 90-lb pot for $325, until they raised the price to over $500. That made me more than a little miffed at them... Then, I got to thinking - It wouldn't be worth the effort for me to build my own when I could get theirs for $325, but now, I'm pretty sure I could build a better pot than their's for way less than $500...

My first and biggest question is: Who makes a respectable (in terms of holding a steady temperature at the temperature range we're dealing with) thermostat?

[Morgan Astorbilt]

There's a fellow selling a Honeywell controller on the swap forum.

[MakeMineA10mm]

Thanks for the heads-up Morgan. That's a little more involved than I wanted to get, although it does look like it would hold a steady temperature!

No one else have any advice/thoughts/suggestions???

Has no one tried this? (I find this hard to believe with some of the resourceful people we have around here...)

[MakeMineA10mm]

Let's try the question a different way:

If you were going to design your own casting pot, what features would you want on it?

I have a long list already, but I'd like to see what others think.

[montana_charlie]

I have no intention of building a pot, and I am not interested in bottom pouring. But, if I was...I would consider a very heavy metering pin.

A very fat section would provide weight to keep the spout from dripping, and a heat storage source to help smooth out temperature variations.
A pot designed from the start to have ample capacity would not suffer from having such a fat rod taking up space inside.
CM

[MakeMineA10mm]

Great idea, Charlie! Thanks.

[Nueces]

Remember that the fat part will displace a lot of lead if submerged, causing a buoyant effect and necessitating more weight above the melt surface to provide down force. Keep the submerged part slim.

Mark

[Ghugly]

Remember that the fat part will displace a lot of lead if submerged, causing a buoyant effect and necessitating more weight above the melt surface to provide down force. Keep the submerged part slim.

Mark

Great point. Think of it as making a hot water dispenser and using wood as your stopper. Using a larger chunk of wood would just make the situation worse. Having as thin a rod as possible below the lead level and the proper weight above, would be the answer.

Consider making the pot more wide than tall. The weight of the highth of lead willl seriously affect the metering. A tall, narrow pot will require more frequent adjustments than a short, fat one.

Insulate it well. The temperature differential between molten lead and the surrounding air is so great that keeping a constant, even temperature will be a real problem without it. An insulated lid of some sort might be a real plus.

[GSM]

Try this link:

http://hgmould.gunloads.com/newpot/instructions.htm

Tom did a great job

[montana_charlie]

Remember that the fat part will displace a lot of lead if submerged, causing a buoyant effect

Keep the submerged part slim.
I didn't consider that, Mark!
And, that sort of thing doesn't get by me very often.

I guess I am still suffering from the ignorance that was mine the first time (1974) I melted a pot of lead. I was temporarily amazed when I dropped my (heavy) Lyman cast iron dipper in the pot...and it floated!.

I thought I had outgrown that by now...
CM

[RU shooter]

I didn't consider that, Mark!
And, that sort of thing doesn't get by me very often.

I guess I am still suffering from the ignorance that was mine the first time (1974) I melted a pot of lead. I was temporarily amazed when I dropped my (heavy) Lyman cast iron dipper in the pot...and it floated!.

I thought I had outgrown that by now...
CM If the stopper pin being lighter than the alloy and wanting to float upwards is an issue ,What about using a 1/4-3/8" pc. of tubing with a solid pin welded to the bottom as the actual plug per say you could fill the tubing with lead for more weight.
just a thought.

Tim

[MakeMineA10mm]

Actually, guys, I already got the bouyancy angle covered... In semi-copying the lever-design of my Ballisti-Cast Machine, I'm going to mount two heavy-duty machine springs to the top of the lever, on the valve stem end to keep down-ward pressure on the valve. Thus, pulling the chain hooked to the other end of the lever will not only need to raise the valve, I'll have to be strong enough to over-come the spring pressure... (Actually, it's not that hard, only a few lbs. of pressure are required. I've manually cycled the valves on my Ballisti-cast when my air compressor was having "issues"...) :roll: :mrgreen:

Good thinking all the way around though.

Thanks for the link to that CB project. Missed that somehow. That is quite educational. I'm re-considering if the $525 is money well spent now... :veryconfu

He did things similar and at the same time different then I thought of...

Will keep cogitating on this project and looking for more ideas...

[ANeat]

This is an interesting project. I remember when Tom made that big cooker well. I think a key to saving a good bit of cash on a project like this is to use some readily available items. Seems like one of the big cast iron crock pots would be a good canidate for the pot itself. I always liked his use of the stove heating elements and think that is a great and inexpensive way to get the heat to it.

After that the solutions are the valve mechanism, some type of stand, and insulation would be great also.

Tha bad part about the iron pot is not being able to easily weld to it so any thing mounted would need to be clamped on or bolted on.

I think a big pot like that would be great for a smelting setup also. No gas needed and bottom pour would be a slick way to fill up ingot molds.

Some nice digital controllers are available and a couple of solid state relays could handle the current

[HotGuns]

I made a bottom pour pot out of 8 inch pipe that works great. The valve is a peice of 1/2 " dia. steel with a 1/4 radius on the bottom that seats against a 45 degree seat on a 3/8" hole.

The lever that operates it is attached to the vave stem by means of a groove machinied into it. Its seals very well and is very quick acting. It seals well enough that if filled with water it will not leak.

There is a thread on it here. http://castboolits.gunloads.com/showthread.php?t=18254&highlight=Hotguns I see no reason why you couldnt use the same setup on an electric pot. I use a a propane burner for a turkey cooker that does an exellent job.

I made it to fill up ingot molds and it does this at a pace that you have got to see to beleive.

[MakeMineA10mm]

Well, my biggest problem with this project is the heating element. I saw and liked the simplicity/cheapness/availability of the stove-top heating elements, but...

If I go through all the effort of doing this, this needs to be the "ultimate" casting pot. One of the design criteria is fast melting of the alloy, so that I don't wait 100 minutes to do 25 minutes worth of casting... Also, re-melting sprue and rejects and fresh ingots in a half-drained pot would be nice to be fast. Toward that end, I've LOVED the pot on my Ballisti-Cast. It has two features that I believe make it melt and re-melt so fast: 1. 220v, and 2. IMMERSION elements. The element does not go under or around the pot, it goes inside the pot, so that it heats right against the lead alloy... This, I believe (please chime in if you think I've got it wrong), is a huge reason that Ballisti-cast pot melts lead so fast/efficiently.

I priced some immersion elements at Grainger and of course, proud of their stuff that they are, they were $500 to $1200........ Not exactly in my price range.

Hotguns - I like your project even better than the other one. They're both great home-built pots. Several ideas similar to mine... 300 lbs of alloy is a bit much for me. I get nervous with 20 lbs of 700-degree lead in a liquid state, so 100lbs is the limit on my pot! :-)

[HotGuns]

Just a thought here...could you use some electric stove elements to heat the lead? If it worked, it'd be a whole lot cheaper the 500-1200 bucks.

[MakeMineA10mm]

Hotguns, I don't think stove elements are set up for immersion heating. I've found a guy locally who knows a little more than I do, and he explained to me that heating elements are special alloy and cannot be fiddled with after they are formed. In addition, he told me that immersion elements have a coating over the top of the element itself. I think I see now why Ballisti-Cast wants $1500 for a 100 lb. pot...

[Texasflyboy]

so that I don't wait 100 minutes to do 25 minutes worth of casting... Also, re-melting sprue and rejects and fresh ingots in a half-drained pot would be nice to be fast.

The 4.5KW pot I made is ready to cast in about 20 minutes from a cold start 3/4 full of cold lead.

Once hot, adding sprues has zero effect on the temperature of the already hot lead.


The heating elements are 6" stove elements at 1500 watts each.

[floodgate]

10 MM:

Stove element jackets are (or used to be) made of the nickel-bearing alloy, Incoloy 800 (from International Nickel Co.). We used it for the exposed boiler tubes on the "Power Tower" 10-MWe solar power plant near Barstow, CA, where I served as DOE on-site rep and VIP tour guide 1982-84. The funny thing was, carbon content was not a critical factor, and I-800 could run anywhere from, 0.1% to 1.0%, which made no difference in stove elements, but had a BIG effect on heat-treatability and tube tensile strength. We got our tubes in two batches, the higher carbon one being designated "Incoloy 800-H". As I recall, one was used for the boiler tubes, and the other - suitably heat treated and sized - for the superheater tubes; we ran about 1000*F/1000psi at the outlet to the turbine.

floodgate

[Texasflyboy]

Seems like one of the big cast iron crock pots would be a good canidate for the pot itself.

No. In my opinion, absolutely the worst possible choice for a homemade casting pot.

Due to the irregularities found in cast cookware, and based my my personal experience, you can expect the cast iron pot to crack at precisely the worst possible time, when it's full of lead.

Been there, done that. That's why I choose plate steel and welding.

[MakeMineA10mm]

So, Tex, is yours the one that the first link above is to? The one with a Lee spout and modified spout plug, and the three stove burners?

If so, your statement about speed of heating up is very reassuring. Maybe I don't need to go the immersion element route...

[hunter64]

What about an old propane tank for pot, not the little 20 lb. but the bigger one and cut it in half or something like that?

[Texasflyboy]

[QUOTE] So, Tex, is yours the one that the first link above is to? The one with a Lee spout and modified spout plug, and the three stove burners? If so, your statement about speed of heating up is very... [\QUOTE]

Yes, that is my link. I made that page rather quickly after my original webspace closed down and I needed to archive the post from Cast Boolits.

I've since found more webspace here at Cast Boolits, but I haven't had time to update the links.

The owner of Cast Boolits has the CD that has all the information from that project.

I sent him a CD in order to support the site, so contact him and you can get a copy of the CD if you want one.

You can PM me with questions about the build.

Tom

[MaxJon]

No. In my opinion, absolutely the worst possible choice for a homemade casting pot.

Due to the irregularities found in cast cookware, and based my my personal experience, you can expect the cast iron pot to crack at precisely the worst possible time, when it's full of lead.

Been there, done that. That's why I choose plate steel and welding.

Texas, I made a bottom pour cast iron pot, so far so good, but i am not 100% happy with the valve design etc.... I am going re hash it, maybe i should make it with carbon steel tube?? Sure would be easier to machine/weld etc...

[MaxJon]

Anyone tried an alloy pot? Not sure how it would handle the heat?
Any thoughts/experiences??


Just read some scary stuff on alloy pots!!! Goin to steel fabricate mine now, sounds like the safest bet!!

BB03

[Ugluk]

I've made my own bottom pour, and if I ever make a replacement for it it will be a different shape.
The one I have is round and insulated, so the spout is placed 1,5" from the outer edge of the pot. Starting from scratch I would angle it slightly outwards.
Also the pot would be shaped to have a corner facing me so to allow the best possible visibility when pouring.
Then I could have the pot at a height where I could rest my arms more and still see where I'm pouring.

[dragonrider]

This is my bottom pour smelter, thumbnails so click for a bigger pic.
http://img.photobucket.com/albums/0603/PaulGauthier/SMELTER/th_IMG_0153.jpg (http://smg.photobucket.com/albums/0603/PaulGauthier/SMELTER/?action=view&current=IMG_0153.jpg)
http://img.photobucket.com/albums/0603/PaulGauthier/SMELTER/th_IMG_0154.jpg (http://smg.photobucket.com/albums/0603/PaulGauthier/SMELTER/?action=view&current=IMG_0154.jpg)
http://img.photobucket.com/albums/0603/PaulGauthier/SMELTER/th_IMG_0155.jpg (http://smg.photobucket.com/albums/0603/PaulGauthier/SMELTER/?action=view&current=IMG_0155.jpg)
http://img.photobucket.com/albums/0603/PaulGauthier/SMELTER/th_IMG_0156.jpg (http://smg.photobucket.com/albums/0603/PaulGauthier/SMELTER/?action=view&current=IMG_0156.jpg)

Does the job.

[Casting Timmy]

I'm hoping to build a pot for myself this spring.

I want to do a rotary valve bottom pour so that when you close the valve it has a cutting action for crud, or at least hopefully it will work that way. If nothing else it won't be able to float up, or at least that's the though.

I'm also using a ceramic heater as I have the thermocouple mounted to read more of my pouring temperature than the heater temperature. This heater will be able to take a little overshot on the temperature set point as the thermocouple catches up. I've mounted the thermocouple the same distance from the outside of the pot as the valve.

I'll probably stir up a lot of conversation with saying you don't need a solid state relay. I used to work for a heater manufacture and a lot of our equipment used heaters on PID controllers and relays. I even did a project were we ran heaters very hard trying to get them to fail using PID controllers with relays. After a couple months running 24/7 and a couple of heaters the relays were still running strong and we never had a problem with them. It was also interesting that all of our heated process machines usually went through a few heaters before we ever had to replace a PID controller or relay. Typically controllers and relays were replaced because the machines were being updated with two hand safeties to ensure no one got their hands in the press as it was closing. They replaced everything in the rebuilt even including the control box of the machine.

[MaxJon]

I'm hoping to build a pot for myself this spring.

I want to do a rotary valve bottom pour so that when you close the valve it has a cutting action for crud, or at least hopefully it will work that way. If nothing else it won't be able to float up, or at least that's the though.

I'm also using a ceramic heater as I have the thermocouple mounted to read more of my pouring temperature than the heater temperature. This heater will be able to take a little overshot on the temperature set point as the thermocouple catches up. I've mounted the thermocouple the same distance from the outside of the pot as the valve.

I'll probably stir up a lot of conversation with saying you don't need a solid state relay. I used to work for a heater manufacture and a lot of our equipment used heaters on PID controllers and relays. I even did a project were we ran heaters very hard trying to get them to fail using PID controllers with relays. After a couple months running 24/7 and a couple of heaters the relays were still running strong and we never had a problem with them. It was also interesting that all of our heated process machines usually went through a few heaters before we ever had to replace a PID controller or relay. Typically controllers and relays were replaced because the machines were being updated with two hand safeties to ensure no one got their hands in the press as it was closing. They replaced everything in the rebuilt even including the control box of the machine.

Care to share any photos?? Sounds interesting, I am currently rehashing my billet steel pot approx. 40lb capacity. I am open to valve suggestions!
BB03;-);-);-);-)

[Casting Timmy]

The valve didn't work, but I made it using a1/2" bolt and coupler nut. I cut the bolt down so the threads went about half way through the coupling nut. Then I screwed it in all the way to the coupling nut and backed it off a half turn before drilling through the coupling nut and bolt. Finally I styled up the center of the bolt. The lead leaks through the threads so I wouldn't try it unless you cut a custom bolt for the nut. I was hoping it would work as the threads would have been great teeth for cutting up crude that was in the valve.

I itf worked I was also hoping to use a set screw for my nozzle so that I could easily adjust the flow rate.

I need to start it again, but I haven't figured out what I want for Valve yet.

[MakeMineA10mm]

Timmy, IIRC, most of the guys who make their own pots, or replace the broken controller from a factory pot, use PID controllers. Everyone here seems to have really good luck with them, as you stated you did at your work.

[MaxJon]

I am removing the bottom pour valve, and making mine a dipper pot! May even convert my Lee 20lb bottom pour also! Sick of poor quality, poor fillout of my moulds with the bottom pour ! Bring on the Ladles!
BB7.62

[blikseme300]

Hotguns, I don't think stove elements are set up for immersion heating. I've found a guy locally who knows a little more than I do, and he explained to me that heating elements are special alloy and cannot be fiddled with after they are formed. In addition, he told me that immersion elements have a coating over the top of the element itself. I think I see now why Ballisti-Cast wants $1500 for a 100 lb. pot...

Reshaping stove or even elements is not easy or typically successful. They can break quite easily.

Bendable elements are available from McMaster - search for Bendable Tubular Immersion Heater Elements.

There are other options. See what I did for a large smelting setup here: http://bliksemseplek.com/boolits.html

Bliksem