Old propane bottles

[bobthewelder]

Has anyone here ever considered using an old propane bottle as a smelting pot? Cut the top off, or even in half and you have a fairly large capacity pot. Just my ramblings, feel free to join in at your liesure.

[StrawHat]

Bob,

I ahve thought of this but am not sure of what the BBQ tanks are made from.

If a ferrous alloy, I would try it.

On top of a turkey fryer, what a set up!

[Lee W]

I did it. Filled it with water and cut it in half with a chop saw.
It holds about 200lbs filled to the rim

[bobthewelder]

And I would think that the rim around the bottom would help speed up the heating process. Thanks! I'm gonna do it. Did you use the small common type or a larger one? Any problems with the thin material of the cylinder?

[357maximum]

Just be careful of remnant gas in the pores of the metal...bad things can happen...proceed slowly and cautiously. steel can hold gas longer than most would think....

[waksupi]

Mine has worked for about a ton of lead so far.

[mtgrs737]

Cast iron dutch ovens at Harbor Freight are just too cheap for me to go cutting up a Propane tank. The lid on the oven will help speed the melting by keeping the heat in.

[bobthewelder]

You have a lid on the propane tank as well. The top! I have a #8 Dutch Oven but need more room. I also need more melting solution! If you have an over abundant amount, I will buy it a fair price.

[MT Gianni]

There are a couple of ways to cut a tank. Pull the valve after making sure it's empty. [leave it open and turned upside down for a day or more] Then fill it with water or even better exhaust from a rumming engine will leave it with a oxygen depleted atmosphere and you can cut it with a arc welder heavy rod and high amps, grinder or torch. A chisel and hammer work also. Gianni

[Leftoverdj]

You can blow yourself to hell and gone cutting on propane tanks. Water filling or equivalent is essential. Being the cautious sort, I vented mine with a .45-70 and left it for a week, then water filled it a couple of times before cutting.

Wasn't worth the effort. The base got glowing red in the smelting. Made me plumb nervous having 150 pounds of molten lead supported by a base on the edge of collapse. If you got a better idea for a base, have at it. It works fine as a pot because the lead absorbs heat. It's that ring base that gets dangerous.

[MT Gianni]

As an aside. I have had the "privelege" to work one tank BLEVE [boiling liquid expanding vapor explosion] and watch a tank split while full on it's side due to a fire. The first case a chimney spark landed on the astro turf covering a deck starting it on fire. The propane tank was on the deck and the relief could not handle the rapid expansion of the gas. The tank bleved and scorched grass and 2" of snow down to the dirt for a 40'-60' radius along with setting the rest of the house on fire. The deck collapsed on the gas meter breaking the regulator and burning the gas at the point of the flames. I came in to the picture as in "Go crawl under the burning deck and shut your gas off. We'll put a hose over you". Some plans work ok, this one did too.
Incident #2 was at a bbq where someone had a homemade grill catering a party of utility workers at a cabin outside Colstrip. The 30 lb tank was on it's side rather than upright. Grease from the steaks flared and burned dripping on the tank and heating it. It began to relieve liquids. Fire extinguishers were brought over but too late. The cabin had about 12 psi of water and a hose would not put out more than you could pee. We cleared people out of the way and watched the fireballs untilit was empty. One guy went to the Clinic with burns nothing major.
Based on those observations I would only heat a tank from the bottom and where there is alloy or ingots/ww present as a heat sink. I would not use a torch or weed burner on the side as I believe the metal is rather thin and susseptable to fatigue heat failure with out a heats ink. Still they are cheap. Gianni

[Down South]

Through the years I have cut at least six of the large propane tanks into with a torch. I always made sure the tank was empty by removing the valve and turning the tanks upside down for about a week. I would remove every plug and valve on the tank too. I filled the tanks with water and then cut them. It’s not easy cutting a tank with a torch that has water in it. The water cools the metal and causes blow back. You will get a lot of popping inside the tank while cutting. Another problem is after you cut into the tank, you are going to get some water out of whatever is venting the tank. What I mean is when you are cutting you will be using around 40 psi oxygen pressure to the torch. This pressure is transferred to the inside of the tank and causes water to shoot out your vent. This water depending on the size of the tank can be hot enough to scald someone. I know from experience. I cut into an 8” pipe once that was standing vertically and sealed at the bottom but was wide open at the top. While making my cut water shot out the top of the pipe showering me. I spent a day under a fan to help cool the minor burns on my back.
To be honest with you, I will never do it again (cut a propane tank). I know that it has been done safely for years but I just don’t want to take the chance anymore.
I know that you are actually referring to a smaller propane tank but you will run into the same problems. I would also think over the long run the smaller tanks thin wall material might cause a problem.
Trust me, buy the cheap Dutch Oven and you will have a great smelting pot.

[bobthewelder]

I have a dutch oven, I just wanted to melt more at once. I have other options, I have some thick walled 10" pipe that I can weld a cap on for a bottom.

[blysmelter]

Remove valve, leave for some days, fill and empty with water a couple of times, cut with a airpowered grinder while the tank is full of water.

[Down South]

I have a dutch oven, I just wanted to melt more at once. I have other options, I have some thick walled 10" pipe that I can weld a cap on for a bottom.

The 10" pipe would make a great pot. I've considered doing the same thing. I too have some 10" pipe and was thinking about making a smelting pot out of some of it. I already had a couple of old dutch ovens so I'm using one of those for now.

[lovedogs]

I don't think I'd use a dutch oven. I'd be afeared of gettin' lead in my chili. 'Course then I'd have an excuse for having lead in the seat of my pants. Har, har!

[4thebrdz]

Small bottles can be refilled with a Threaded burshing fitting from large BBQ style bottles. I made my money back the first time I filled 4.

[georgeld]

I have two 100# tanks and refill them at the farm gas outlet for less than half price. This last Nov it was $35/100#, locally near town they want $65. P on that!

Made up a transfer hose and hoist the 100's upside down and refill the five gallon/20#, get six or seven per tank. We use them by the dozen's elk hunting in cold weather etc, and other use's.

Somewhere on the "smelting equipment/pots" or the like titled thread are some pictures of a big copy of Lee's propot I welded up from 9" pipe. Lot of info there. go check it out.

Needle valve, outlet pipe, heat shield tin side's to keep from burning your legs. Weed burners for torch. That kind of stuff. Worth your time to go look it up.

[calsite]

my sentiments exactly, I believe you can have to tank purged with air, or like what was stated above fill with water before cutting. Inovative idea........

[bobthewelder]

Wow, $35.00 for 100#! I have not filled one since I stopped brewing beer but I was paying $45.00 for 40# a few years ago. We only have one place in town that I know of that fills. The rest are Rhino exchange stations. I'm gonna have to hit some of the sorrounding towns with Co-Ops, there has to be cheaper propane to be had if your paying $35 for a 100 pounder.

[yeahbub]

My solution for the need for a melt pot was to get a 30gal SAE air compressor tank away from the junk man for $30, mark it off in thirds and cut with a 4.5" grinder using a cutoff wheel. For a burner I got a $40 turkey fryer burner from Sportsman's Guide, but was disappointed in the amount of heat it put out, so I got a $26 weed burner from Harbor freight and now have heat to spare at 20% throttle. The piezo-electric start button is nice, as is the "turbo lever" which is good for burning off the smoking debris and dirt in a fresh load of WW. The tank metal is plenty thick (.25" or so) and I expect it'll last some years.

[Ghugly]

I've been pleased with my propane tank smelting pot. I got lucky, I guess. A friend of mine was using it as an air tank for a couple of years before I got it. I figure a couple of years of air being cycled through it cleaned it of propane pretty well. I chopped the top off with a sawzall. I usually do about 150 pounds at a time and its been rock-solid for me.

[bobthewelder]

Thanks Ghugly, two questions, no three. Is that a propane heater with the hat taken off you are using for a burner? What is in the cat's mouth? Where is the rest of the cat?

[Ghugly]

Thanks Ghugly, two questions, no three. Is that a propane heater with the hat taken off you are using for a burner? What is in the cat's mouth? Where is the rest of the cat?

Sorry for the delay. The burner is home built natural gas fired, using the top from the propane tank as a base. The cat is chewing on a hot dog. The picture is the burner at night with the pot off. With the jet I'm using now, it throws about a 3 ft flame. Natural gas is really cheap to use and puts out plenty of heat.

[miestro_jerry]

Guys,

I have made to crucible smelters from 20 and 30 pound propane bottle. You need to line the bottle with KAO Wool or other mineral wools, then coat the KAO wool with some refractory, like ITC 100. You can make the burner at home:

http://anvilsandinkstudios.com/burner.html

I smelt bronze regularly as well as lead, aluminum and copper. Spring I am building a small building for my foundry.

Many times I use a 20 pounder propane bottle cut open and a turkey fryer burner for melting lead. If you want to try this, wrench the valve off the bottle turn the bottle upside down for a week. then flush the bottle out with wayer, drill a hole at the mid seam, then use a metal cutting blade on a sabre saw to cut the bottom away from the top. Works great.

Jerry

[BeeMan]

I've cut numerous 20 lb propane tanks after prolonged venting. Never used a torch, but an angle grinder or drill bit to get started then cutting with a metal cutting reciprocating saw works fine.

I trust a propane tank that was hydro tested and had little to no rust over a cheap chinese cast iron pot. Cast iron is good for heavy machine tools or in compression but the large flat bottom of dutch oven isn't the best application. I've processed hundreds of pounds of WW in a propane smelter over propane burners and wood fires. Refrigerant tanks are quite a bit thinner metal and I'd avoid them for smelting.

Use a little (not so) common sense and you can make a fine smelter. Add 3 or 4 legs of 3/4 black pipe and the weight of a loaded pot sits on the ground rather than on your heat source.

Propane bottles also make great squirrel proof deer feeders, forge bodies, and much more.

BeeMan