propane tank smelter question

[oscarflytyer]

Have a used propane tank (properly purged) to hack for a smelter. Tried cutting it in half with a Sawsall - MY gawd the thing is hard. hence the question.

I started the cut just above the weld seam. After attempting this, and making nearly no progress... Do I need to cut along the very middle of the weld seam? Is this easier to cut along the seam than the tank case itself? Thanx

[warf73]

I cut mine just below the weld seam. I used a cut off wheel in my 7 1/2" skill saw, it took 1 full blade and about 1/4 of another.
There is a band between the halfs that make it thick. I'll take a pic of mine for ya and post it later this morning. I cut my tank in half about 3 weekends ago and have ran a batch of lead threw it already.

[altheating]

I used a good metal cutting jigsaw blade. I cut mine right at the edge of the weld. Started with a small hole drilled right at the weld line. I don't think it took three minutes to cut it in half. Wear SAFETY GLASSES !

[gwpercle]

On Hows That Made they showed the manufacture of the tanks. The seam line is a little thicker for the weld and they temper the steel after fabrication so it will be hard and tough to withstand high pressure... the steel is tough but not brittle.

whatever you use to cut one in half with just make sure it's designed to cut tough metal.

[10 ga]

I did my tank with a sears rotozip with an abrasive metalcutting wheel. Marked it with a magic marker and just followed the mark around a couple of times. It was full of water and when that came out the cut in a couple of places I knew I was close to through. Then finished it off. I cut mine higher up just below the shoulder to make a bigger pot. Use the top as a cover to save heat when I start a batch of "ore" on the way to ingots. 10

[bumpo628]

Here's the pot I got from one of the members here D Crockett
http://i147.photobucket.com/albums/r298/bumpo628/IMG_20110903_180939.jpg
http://i147.photobucket.com/albums/r298/bumpo628/IMG_20110903_181002.jpg
http://i147.photobucket.com/albums/r298/bumpo628/IMG_20110903_181013.jpg

Here it is after I painted it with high temp bbq paint:
http://i147.photobucket.com/albums/r298/bumpo628/IMG_20110903_185146.jpg

[Oreo]

How much weight you think the metal ring on the bottom of the tank will hold? I'd hate to have 150+lbs of molten lead take a spill cause that metal ring base folded up under the heat & pressure.

[tcbnick]

I cut mine off at the weld seam, used a "quickie saw" . as far as weight I stood in mine and the ring held just fine, thats 200 # on one foot.

[Oreo]

Thats 200lbs @ room temp. What about @ 700-900°F?

What about 400lbs? I'd like to be able to do large batches to keep alloy consistency.

[338RemUltraMag]

I like this, and since I got a couple old tanks, I may just try it...

[D Crockett]

for those of you that have not had any experence in cutting propaine tanks open don't do it the reason I say this is I went to school to learn how to do this safely I build bbq grills and smokers out of big tanks if you do not do this right you can get hurt or even killed cutting one open and cutting one open with it full of water using a power tool is not a good idea this is just a word of WARNING so I do not here about one of you getting hurt or worse D Crockett

[a.squibload]

D Crockett, I like the pour spout. I need to put a handle on mine,
might do a spout too.
For all the work involved yours looks like a dang good deal!

Here's a previous thread on this subject:
http://castboolits.gunloads.com/showthread.php?t=92447

I used a thin cutoff wheel in an angle grinder, plugged into a GFI 'cause
I had filled the tank with water. Wet but safe. Probably overkill as the tank
had been sitting in the sun for a while with no valve in it. Purchased for $1
from a propane dealer. Makes a nice lead pot!

Got a tip from Fugowii,
cut a 3" wide ring from the top half, welded it to the bottom.
Very stable. I drilled holes in it for the flames to escape, maybe
not necessary.

Here's mine:
http://castboolits.gunloads.com/showpost.php?p=1043328&postcount=15

Here's Fugowii's:
http://castboolits.gunloads.com/showpost.php?p=970126&postcount=25

[warf73]

for those of you that have not had any experence in cutting propaine tanks open don't do it the reason I say this is I went to school to learn how to do this safely I build bbq grills and smokers out of big tanks if you do not do this right you can get hurt or even killed cutting one open and cutting one open with it full of water using a power tool is not a good idea this is just a word of WARNING so I do not here about one of you getting hurt or worse D Crockett

People have been converting propane tanks into smelting pots for quite some time now and no one has blown themselfs up. All you have to do is aply some common sence and you will be fine.

[DukeInFlorida]

I cut mine ABOVE the weld seam, and then cut another two inch circle from the remaining top, and tack welded that ring to the bottom (outside of the existing bottom ring) to make a wider support. 150+ pounds of molten lead makes me nervous without proper support against tipping.

Should look like:
http://www.northeastshooters.com/vbulletin/threads/101136-The-Bullet-Casting-Info-Megathread?p=1492320&viewfull=1#post1492320

http://i73.photobucket.com/albums/i227/BP_2006/07_12_2010003a.jpg

[Moonman]

warf73,

I have some news for you, "The WORLD is FULL OF PEOPLE WITHOUT A LICK OF COMMON SENSE." :veryconfu

[D Crockett]

Moonman you hit it right on the money that is why I put the warning up just to let people know in my town a few years ago we had someone killed opening up a propaine tank so evey time I see a thread I will post a warning on the safty of opening a tank I think there should be a sticky on this D Crockett

[oscarflytyer]

Don't tell my wife I might blow myself up... If she knows that, she will be egging me on for the insurance $$$!

If you happen to see a bunch of guns for sale in the very near future...

[afrance]

I used a sawzall and just cut the bottom off, then welded angle iron legs to it with 3/4" rebar welded in the corners of those legs to add strength. made it into a bottom pour smelter and it can easily do 300lb batches, so long as I have enough ingot molds to keep up.

Pictures and description are at http://castboolits.gunloads.com/showthread.php?t=56062 , but now I use a high pressure burner and wrap the tank in fiberglass insulation surrounded by aluminum foil when I am doing large batches.

[Longwood]

Here is one I started last year but did not finish.
I have the valve made for it but I may drill and install it if my spout idea works.
The plan is to weld a small spout into the side with the hood that has an inside tube going down into the melt, sort of like the bottom pour ladles.
I may not need the internal tube since I began using sawdust for flux and don't have junk on top of my melts any more.
A simple spout on the side with the hood and a couple of pieces of round stock ears on each side so I can tip the whole works like a big blasting or foundry furnace.
I would change the shape of the hood some so I would not have to worry about spilling around it if I were to make another one.

[a.squibload]

Never thought of it that way.
Couple of thoughts, if you're pouring out the top make the handle or handles
kinda long for lots of leverage, better control.
Maybe a rod welded at the bottom of the pot on the spout side, or angle iron,
crossways to the spout, sticking out a few inches left and right.
Would keep it straight, keep it from rolling to the side.

Now I'm seeing a chain hoist with hooks, and pipe welded to both sides of the pot
to hang it from, lead flowing and sparks flying...
naaah, you'd have to hire a couple of guys to keep moving the ingot molds, etc.
But it would be fast!

[338RemUltraMag]

If I cut into a tank I will have it vaccuum purged and filled with water, hell I might even talk to someone who has done this before...

[warf73]

warf73,

I have some news for you, "The WORLD is FULL OF PEOPLE WITHOUT A LICK OF COMMON SENSE." :veryconfu

Guess if your that dam stupid then you shouldn't be reloading in the first place let alone playing with molten metal that is 700*.

You can't fix stupid no matter how hard you try.

[Longwood]

Never thought of it that way.
Couple of thoughts, if you're pouring out the top make the handle or handles
kinda long for lots of leverage, better control.
Maybe a rod welded at the bottom of the pot on the spout side, or angle iron,
crossways to the spout, sticking out a few inches left and right.
Would keep it straight, keep it from rolling to the side.

Now I'm seeing a chain hoist with hooks, and pipe welded to both sides of the pot
to hang it from, lead flowing and sparks flying...
naaah, you'd have to hire a couple of guys to keep moving the ingot molds, etc.
But it would be fast!

Thanks for the tips.
If I cam figure out a good balance point, I should be able to get by with a fairly short handle. I plan on filiing the pot with ingots for testing.
I will have to set the ingots on a stack of half-bricks so I can lower the molds as I have to tilt the pot farther.
I had started out planing to build a bottom pour so I made a valve and began modifying the bottom of the tank so I had a flat spot to put the valve.

Originally. my plan was for the hood to be a safety shield to stand behind when adding new junk to the pot. Then I got to thinking that it sure would make the pot easier to tilt without the danger of spilling lead.

Because of the junk that could end up in the valve, I may abandon that idea all together if my spout idea works.

I found an old primer in the bottom of a pan of scrap lead someone had recycled and I bought, pan and all.
Afer I got it, it had rained into the pot so the primer would never have gone off the day I discovered it, but I wonder if it would have before the rain.

[Oreo]

I think tipping a huge pot full of molten lead is an exceptionally bad idea. One wrong slip and you're potentially getting one or both feet amputated. Ladling ingots is more work but is inherently much safer.

[Longwood]

I think tipping a huge pot full of molten lead is an exceptionally bad idea. One wrong slip and you're potentially getting one or both feet amputated. Ladling ingots is more work but is inherently much safer.

Be cool, and watch!
It won't be any where near as dangerous or messy as a ladle if "I" build it.
The idea is an after thought on this tank. If I start over, it will be even more accident proof.
Plus, it will never get junk in the valve and leak all over the place if I don't put one in.

By the way, molten lead spills are only warm.
:kidding:
I used to work at a nickle smelter where the spills were 3100 degrees.

[Oreo]

Im not saying it can't be done, just that the price of failure is very high. If you're confident in your ability, your knowledge, and your design enough to put your flesh on the line then I wish you well. I'm interested to see what you come up with. Not so interested that I want to see it in person however. ;)

[badbob454]

I cut mine ABOVE the weld seam, and then cut another two inch circle from the remaining top, and tack welded that ring to the bottom (outside of the existing bottom ring) to make a wider support. 150+ pounds of molten lead makes me nervous without proper support against tipping.

Should look like:
http://www.northeastshooters.com/vbulletin/threads/101136-The-Bullet-Casting-Info-Megathread?p=1492320&viewfull=1#post1492320

http://i73.photobucket.com/albums/i227/BP_2006/07_12_2010003a.jpg

that is right purty looking , nice idea ..
and looks like it could hold plenty of weight .
thanks for sharing this pic

[badbob454]

how to safely cut a propane tank. 1. make sure its empty ,remove valve (outside )
2. fill with water let it sit for i day with water in it ,.3. pour out water , and immediatly cut in half with valve removed ....
. this is how i did it and it was safe for me

[milsurp mike]

The Safest way to cut is to remove the Valve.Put the tank on a fire pile before you light it.Then light the fire pile and watch the gas burn off.After it cools it is fume free with out a doubt.Mike

[wtfooptimax200]

Mine looks very similar to Duke's (probably because I stole the idea from him at the casting seminar that he hosted)! It works very well. I cut it with an angle grinder and it wasn't particularly difficult.

[DukeInFlorida]

And, here I was, thinking that most of the attendees to the casting workshop were napping most of the day. Glad you are enjoying the hobby!

I'd make mention that removing the valve to the tank is the first step in the process. Allow it to air for a few days, upside down. Propane is heavier than air.

When you get near the purged tank, you will still smell what you think is propane. However....

Propane doesn't naturally have any smell at all. The companies add an organic smell chemical to the propane, so that it's easily detectable. That chemical gets stuck to the insides of the very empty tank. So, don't be concerned in the least if the tank still SMELLS like there's propane in it. Two days of airing out upside down is enough to assure you that there's no explosive gas inside. The chemical smell will go away after the first time you use the smelting pot.

Also, I second the opinion expressed earlier about NOT tipping any of the smelting pots. Even only 50 pounds of lead, at 700 degrees can become very hard to handle. So, no pourin pout is needed. Use a ladle to remove the clean lead (after fluxing) from the pot.

And, leave the last inch or so of lead in the smelting pot, and allow that to cool when you are done. That will provide a 100% contact surface for the next time you fire up the pot. It will make the next melt go much faster, since the heat transfer will have 100% contact to the pot/lead. Even if changing alloys, the little amount of the 1" of leftover lead isn't going to dramatically change your chemistry.

Finally, I give all kudos for the smelting pot design to Patriot at NES. He's the one that came up with the ones that I have copied, and have been shown at the cast bullet workshops. That's actually Patriot's picture I referenced.

Post Script: My most recent smelting pots were the bottom end of some stainless steel beer kegs! The casters who got those are die hard smelters. They said that they had to do some welding on their smelting stand to provide a big enough and strong enough surface for the keg bottom to sit on. The MEGA KEG SMELTING POTS would hold about 500 pounds of 700 degree molten lead. Um,.... you're NOT gonna try and tip it... no sir.

[Daffy]

I thought I smelted a bunch of lead at a time...... 30# at a crack generally works for me. I try to do some shop cleaning between batches and pours! LOL

[JIMinPHX]

if you do not do this right you can get hurt or even killed cutting one open and cutting one open with it full of water using a power tool is not a good idea this is just a word of WARNING so I do not here about one of you getting hurt or worse D Crockett

What is wrong with cutting open a tank that has been filled with water? I understand that tanks with vapor inside are dangerous to cut. I understand that some tanks can give off additional vapors from the heat of being cut & that can cause a dangerous situation. I thought that filling a tank with water or purging it with an inert gas were two of the preferred methods of pre-cut preparation for most average fuel tanks. Please fill me in on what I am missing.

Thanks,
Jim

[Oreo]

You're not missing anything JiminPHX. The point is to purge the propane. There are several effective methods discussed here. The steel does not absorb the propane so once the tank is sufficiently purged heating the steel will not release any combustible vapors.

[JIMinPHX]

The steel does not absorb the propane so once the tank is sufficiently purged heating the steel will not release any combustible vapors.
How about the mercaptan? I think that usually leaves a residue in old propane tanks. I believe that it's one of the more common additives that is used to give propane it's smell.

[geargnasher]

The mercaptan can accumulate through numerous fillings in the form of a black goo on the bottom of the tank, and it makes a world of stink when it gets hot. I did the remove valve/water fill/drain and then cut mine with a plasma torch 'cause I have one and I'm too lazy to use a saw. Not sure I'll use the plasma torch on the next one, it's tough to hold your nose with one hand and cut a straight line with the other!

Gear

[rockrat]

LOL, glad to know "geargnasher" as I bought an 8 gallon propane tank at the salvage yard and was going to cut it with my cutting torch.

I will make sure the wind is blowing a bit, before I do it. Was going to do it in my barn, but not now!!!

[finishman2000]

here are pics of my new smelter. was a 10lb propane tank that was out of date.
i took the valve off and flipped upside down over night. this morning filled with water, flipped over and drained.....done. 10 minutes later i had the top cut off.

[a.squibload]

...it's tough to hold your nose with one hand and cut a straight line with the other!Gear

That's what those little vice-grips are for!

'Course a clothespin is gentler on the schnozz...

[Exclr8]

Have a used propane tank (properly purged).

How do you properly purge one?

[a.squibload]

Basically make sure there is NO propane left in it.
Lots of tips above & in other threads.
The short version (a series of steps, just one step
Will NOT make the tank safe for cutting):
((Disclaimer: if you do it wrong and blow your head off
don't come yelling at me!))

Open valve, point valve downward & let all the gas out.
Carefully remove valve without making a spark.
Leave tank in direct sunlight for a week OR
Put it on some firewood THEN light the fire (with
a 10 ft match).
Fill tank with water and cut it. Optionally you might
remove the water before cutting, I left it in 'cause
I'm no expert!

Another option before removing valve (as improper
valve removal could make subsequent steps unnecessary)
is to shoot a couple holes in the top part of the tank.

Huh, I COULD be a technical writer after all!

[Oreo]

Don't listen to that guy. Whole bunch of bad advice in his post.

** All these steps should be performed away from any possible source of ignition. No waiting is necessary for the process outlined below. Just do each step in order one after the other.

1. Start with an empty tank, or use up the remaining pressure on your gas grill.
2. Disconnect tank from gas grill & open valve on tank all the way.
3. remove valve from tank.
4. Fill tank to the top with water.
(The tank is now free of combustibles. You can light up a fine cigar safely.)
5. Drain water.
6. Cut tank open.

[jblee10]

finishman2000, I like your burner!

[MT Gianni]

Mer-captan is a liquid that is highly flammable. It is added to LP and Natural gas a a rate much smaller than one drop from an eyedropper per 20 lb tank. It will stay in the pores of the steel tank and smell for quite a while. If the tank has been purged with either water or an inert gas, think exhaust, it is fine to cut. Burning one in a fire may reduce the temper of the steel as you are not controlling the temps as when you smelt. I am not predicting that the bottom will fall out just that the temper might change to softer.

[finishman2000]

finishman2000, I like your burner!

i used it for the first time yesterday.....475lbs of wheel weights in 3 hours!

[DukeInFlorida]

Remove the valve, turn the tank upside down for one day. PURGED!

It will still "smell" like propane, but that is the organic chemical that they use to make orderless propane smell so you could otherwise detect a leak. That chemical smell is stuck to the insides, but poses no danger. It would burn off the first time you use the smelter.

One day with no valve, upside down, and it;s purged. No need to add water, etc....


How do you properly purge one?

[Coffeecup]

You know, all safety concerns aside, a guy would be feeling pretty dumb right now if he had been seeking a replacement for the lead pot on his plumbers furnace, and for more than a year had been storing the furnace in the same shed as several old-style propane tanks.

I'm not admitting anything, I'm just sayin' . . .

[a.squibload]

Most of my "bad advice" (???) was gleaned from reading here,
including anecdotal evidence that propane tanks can explode
if misandled. Figured it's better to cover all the bases than to
let a guy start cutting away with gas present!

Didn't consider the annealing effect of a really hot fire, assumed
a fire only big enough to heat up the tank. Again, from someone
else's experience.

There was a guy near here, experienced welder, got killed while working
inside a tank of some kind, it blew up. Safety first couldn't hurt...

[Oreo]

You have to be careful getting advice on the internet. Lots of bad advice on the internet gets passed around by a lot of people as fact. This site is no exception.

[a.squibload]

I still don't see what was bad about it?