Home made zinc melting furnace

[The Double D]

I tried to get some help figuring out how to build a furnace for melting zinc for casting balls for my coehorn mortar and posted over in Cast Boolits topic. My mistake, all I got was advice to use cement and shoot cats. My sincere request got thoroughly trashed and drifted off topic pretty bad, and by moderators no less. Oh well I probabley should have posted the request here under casting equipment to start with, my mistake.

I need to build a burner set up and pot to melt 15 to 20 lbs of zinc. I need some sort of bottom pour pot and a burner that will generate enough heat to melt at the higher temperature required for zinc.

Anybody have any ideas. One thought is to use the burner from one of those Turkey deep fryer setups. Any thoughts on that?

[wills]

Name: Zinc
Symbol: Zn
Atomic Number: 30
Atomic Mass: 65.39 amu
Melting Point: 419.58 °C (692.73 °K, 787.24396 °F)
Boiling Point: 907.0 °C (1180.15 °K, 1664.6 °F)

Bentor, Yinon. Chemical Element.com - Zinc. Jun. 15, 2005 <http://www.chemicalelements.com/elements/zn.html>.

Name: Lead
Symbol: Pb
Atomic Number: 82
Atomic Mass: 207.2 amu
Melting Point: 327.5 °C (600.65 °K, 621.5 °F)
Boiling Point: 1740.0 °C (2013.15 °K, 3164.0 °F)

Bentor, Yinon. Chemical Element.com - Lead. Jun. 15, 2005 <http://www.chemicalelements.com/elements/pb.html

It is only about 160 degrees different. It seems what works for lead ought to work for zinc.

[beagle]

You might look in the back issues of the Fouling Shot for plans. Several years ago, there was a set of plans for a home made gas powered melting pot that was bottom pour and easily handled the volume of metal you're looking at.

It was made from steel pipe and a lot of welding was involved. Made primarily for refining WWs but should give you the volume you're looking for in pouring mortar rounds./beagle

[Willbird]

This might be totally off the wall, and excuse me if it is.....but what about just making a holder to hold a very large cast iron rowell ladle over the burner until it is time to pour ?? heat the ladle itself with the gas flame. The larger Rowells are a two man proposition but they are made to handle metals a lot heavier than Zinc so should be safe.




Bill

[wills]

Is the difference is the volume of metal you are dealing with? Perhaps you could cap some drillstem, set it horizontally and cut out about a fourth of the top put that over your burner.

[The Double D]

Bingo! Rowell Ladle and drill stem.

I have access to some 8 1/2 inch scrap pipe. I'll weld a bottom on the pipe to make my pot. Then I will cut a hole in the side of the pot just down from the top and weld a a piece of 3/4 or 1 inch tube in the hole extending from the hole down to just off the bottom of the pot. Add some handles of some sort and I have my pour from the bottom pot.

I don't have access to Fouling shot. Does some one have a copy of the article they might share with me?

I have considered using these gas burners for heat. Does anyone have any experience with them? Do they get hot enough?

http://www.fototime.com/48ED232F5058938/standard.jpg

Thanks gents for the ideas!

[felix]

That tube diameter is way too much for any molten metal. An accident waiting to happen. A one-fourth diameter might even be too much. Never hurry around this kind of heat, and quit on the first sign of fatigue. Sundog and I had a large pot made by folks who do real pots for a living, like for steel companies, and we followed their advice 110 percent. No spigot operation at all; just ladle from the top. ... felix

[wills]

Seems propane ought to get hot enough, assuming it reaches these temperatures fron the burners shown. One of the members of our club has a propane welding rig he uses to Repair the silhouettes

Combustion Data:
Ft3 of Air Required to Burn 1 Ft3 of Gas: 23.86
Flash Point: -156 deg F
Ignition Temperature in Air: 920-1020 deg. F.
Maximum Flame Temperature in Air: 3595 deg F
Limits of Inflammability, Percentage of Gas in Air Mixture:
At Lower Limit: 2.4%
At Upper Limit: 9.6%
Octane #: Over 100

[Cliff]

Sounds like you are headed in the right direction. I believe a lot of the flack you got about melting zinc is from those who have had problems with zinc contamination of their lead alloys. I remember reading in some publication on the efforts to cast bullets from a zinc alloy for shooting. Seems it pretty much ruins the equipment to the point it will not work with lead alloys again. You might want to look at the various Zinc alloys out there used for die casting. Some are low temp. alloys and some are high. A lot of cannon shooters do use zinc alloys for projectiles so you may have some luck searching around and find out how they do it. It is a popular way to get those big projectiles. I do think something on the order of a fish cooker burner would be needed to achieve the BTU's to do it right. You might want to check with the Antimony man to see if he can suggest something. I think his website is http://www.bullet-metals.com he is Bill Ferguson and is an expert on metals. Good luck.

[wills]

Google "zinc casting" you'll get a lot of stuff & can probably glean some useful information

[Willbird]

I know for a burner it is hard to beat the Gander mountian turkey fryers, I got the whole kit with the kettle and accy, the burner, and the high pressure regulator for 50.00 - 15% off because it was a display model... 35.00, One cannot hardly order a 120,000 burner and regulator for that kind of dough, and I can fry turkeys too :-)

Bill

[C1PNR]

Bingo! Rowell Ladle and drill stem.

I have considered using these gas burners for heat. Does anyone have any experience with them? Do they get hot enough?

http://www.fototime.com/48ED232F5058938/standard.jpg

Thanks gents for the ideas!
IIRC the pictured burners only put out about 12 to 15K BTU, which is really not enough to melt a lot of zinc or lead.

In the old days of do it yourself we used old cast iron water heater burners out of the junk yard. Nowadays I guess the Turkey Fryer is the in thing. Just be sure the stand will hold the weight.

Propane and natural gas should both have a hot enough flame temperature.

[The Double D]

Trykey fryer it will be then. I'll send the wife out to check Yard Sales.

1/4 inch ID spout. Will that be large enough to dump 6 lbs of meatal at once through a 3/4 inch hole?

http://www.fototime.com/DE96B8D9401D468/standard.jpg

I have the source for Zamak Zinc alloy already. I will be remelting range recovered balls.

I have 10 3/4 balls right now. I need 7 for a match, best five count for score.

[Buckshot]

http://www.fototime.com/4F0787827D40539/standard.jpg

This is my scrap lead rendering setup. A turkey frier and cast iron dutch oven. I really think that this type setup is as cheap and efficient a setup as you'll find. With the inline throttle valve and air register on the burner they're simple to regulate. You can make that burner roar like a jet engine, and it's for sure putting out the BTU's, big time.

I suspect that that iron pot will hold 80 pounds of lead, maybe 3/4 full.

You are pouring quite a quantity of molten metal for each pour so I'd suggest you fabricate a type of founders crucible with that steel pipe you have. I don't know what equipment you have available for fabing up something, but I would make it safe and substantial and easy on you to operate.

If you see yourself pouring by yourself possibly the following idea might have merit. Material choice would be up to you. For my example I'd say 3 legs flat on the ground and a central vertical post of a suitable length. Maybe 2" gas pipe for this? A plate with a 1" bolt through it and welded, then this centrally welded to the top of the vertical post. An arm of suitable length with a hole bored to fit over the bolt on top of the post.

Your 8" steel crucible, formed with a pouring lip would be suspended from this arm via 2 opposing studs welded to the side of your crucible. I would use maybe 3/4 or 1" pipe to come down from the arm with a 'U' on the bottom with a hole in each arm of the 'U' to fit over the studs on the crucible. On the bottom edge of the pot is a welded on ring.

In operation the pot is suspended over the turkey fryer burner. When up to temp you swing the arm bringing the crucible around to your mould. With a rod having a hook on the end you use the ring on the crucible to lift it's base and pour the zinc into your mould. Via the solid pipe down from the arm, the pot will not swing, but would rotate predictably .

Possibly having a means to lock the swinging arm would be good. A hole drilled through it into the plate below so you could drop a 1/4" bolt as a pin through it would be effective enough.

With this means the crucible is always in control and is never 'loose'. All your manipulations of it are from a distance. You could safely do this by yourself and wouldn't HAVE to have a 2nd helper. If you wanted to get really fancy you could run a rod from the lifting ring of the crucible to an 'L' arm pivited on the side of the horizontal arm. From the other arm of the 'L', run a rod to a lever pivited at the end of the horizontal arm. You can then stand at the end of the arm, walk the crucible around from the burner to your mould and pull the lever to tip it to pour.

.............Buckshot

[felix]

Go here and take a look at the big pot Sundog and I had built. Scroll down until you find the ladle, and see if a smaller version will work. This ladle holds 20 pounds of lead, and you'd definitely would want to scale this thing down. The design is good, and will be improved some day after we find out for sure on where to put the handles. ... felix

http://www.castpics.net/RandD/moas/moas.htm

Ladel is on page two at the site.

[wills]

Sounds like you are headed in the right direction. I believe a lot of the flack you got about melting zinc is from those who have had problems with zinc contamination of their lead alloys. I remember reading in some publication on the efforts to You might want to check with the Antimony man to see if he can suggest something. I think his website is http://www.bullet-metals.com he is Bill Ferguson and is an expert on metals. Good luck.

try

http://www.theantimonyman.com/

[The Double D]

The swing arm Crucible idea, I had been thinking about. Thanks.

That's a serious lead melter set up...The old guy referred to as weakling is the smart guy. He's wearing long pants and he found a younger guy to do all the work. I think I might look at that approach.

Thanks again guys!

[nighthunter]

That kinda looks like a couple of chicken farmers in those pics. Did ya notice the legs on that one fella? I think they might give some consideration to the fact that normal people might view those pics.
Nighthunter

[VP]

What a set up. I have spent the afternoon melting wheelweights in my 10# Lee Pot. Felix's ladle holds twice as much!
VP

[VP]

I tried to get some help figuring out how to build a furnace for melting zinc for casting balls for my coehorn mortar and posted over in Cast Boolits topic. My mistake, all I got was advice to use cement and shoot cats. My sincere request got thoroughly trashed and drifted off topic pretty bad, and by moderators no less. So are you shooting concrete at the cats, or are you using cats as the projectile?