Cutting a propane tank

[dverna]

I did not want to hijack another thread (cast iron smelter).

How does one safely cut a propane tank? I was thinking of using a metal cutting blade on a reciprocating saw. The fastest way is of no concern - just want to do it safely.

I do not have the ability to weld so fabricating a smelter out of steel pipe with a plate bottom means finding someone to do it.

If there is someone who makes these things I may be willing to purchase one.

Please do not recommend a cast iron pot as I have decided to go with steel. The added cost is worth the safety factor for me.

Thanks,

Don Verna

[jmort]

I got mine from DCrokett but I understand he stopped selling them or hopefully he is taking the winter off. I got a couple nice older tanks from a scrap yard for spring project. Use a 4 1/2 grinder with a metal cut-off blade. Hardest part can be removing the valve. Once that is done hang it upside down for a day and then fill it up with soap and water a couple three times letting it sit and rinse it out.

[Digital Dan]

First make sure there is no residual gas in the tank. Removing the valve and letting it ventilate while upright won't clear the gas, it is heavier than air.

[kens]

I have seen guys weld gasoline tanks by purging the fumes out.
First fill it with water to displace all gases, then dump the water, it will refill with fresh air.
Then discharge a CO2 fire extinguisher into it. The dry ice displaces the fresh air as the the dry ice melts leaving behind CO2.
If you have access to nitrogen, this can displace fumes, as well as the welding gasses of heli-arc, (argon) and mig welding.
You could go to the local supermarket and buy a chunk of dry ice, crush it up and insert it into the tank.

[fryboy]

i used a small blade as you stated on a reciprocating saw ( we tend to call them sawzall even tho that's a milwaukee brand name ) a freon jug for me was smaller and less problematic than a propane jug, foto at link
http://handloadersbench.com/view_post.php?post_id=250265

[mikeym1a]

I have one I started ventilating last fall! My son got the valve out. Anyway, as was said, propane is heavier than oxygen. I will fill mine with HOT water to overflowing, and then borrow a portable band saw from work (rental shop), and use that. No jerking motion to contend with, and as the band cuts through, just advance around the circumference. The got water should have evaporated any residual LP, and filling it to the top should force it out, and with the steady cut of the band saw, no sparks. Should work. Good Luck! 8-)

[grouch]

All good information, but I'm with the fellow on page 1 with the cheap stainless steel stock pot.
Grouch

[dverna]

Thanks to everyone who responded.

Grouch, I will look into a steel pot. I am going to Google that now.

Don Verna

[kopperl]

Got a Stainless two gallon soup pot at Goodwill for $4.00. Works well.
Bill

[merlin101]

I tried to remove the valve on a BBQ grill tank and couldn't get it to budge. Being the gun guy I am and knowing that this tank was empty, I sat it down and backed off about 40-50yds or so and ventelated it with a 30-06 near the top. Then filled with water and a day or two later cut it in half at the seam.
Save the top part and cut it the same height as the base ring and weld on the bottom to make the pot more sturdy.

[lwknight]

It is best to use something thick on bottom. The thin stuff will have hot spots where no lead is touching.
Also the thick stuff distributes heat more evenly to all parts to speed up melting on start up.
Once you get a puddle in the pot , it should not matter anymore.

[catman81056]

Walmart has the SS stock pots really cheap. I think I paid les than $15.00 for a 20qt. Wish I had gotten the 16qt.

[Johnch]

I couldn't get the valve off mine

So I shot it close to the top with the 223
That makes a small hole
But I used it to fill the tank with water and I let it in the tank for a few days

I then drained the tank and used a 4 1/2" grinder to cut the desired pot out of the wet tank

John

[jonas302]

My favorite way to make a tank safe is get a hole in it by any means possible let it ventilate and put it in a brush pile let her burn when you dig it out cut how ever you want no danger possible of course that wont work for everyone

Freon tanks are a bit thinner thats what I use

On the real cheap stainless pots just be aware that the handles can have aluminum rivets not a problem just dont lift by the handles

[Regnar]

Yep, I used an empty helium tank from the kid's birthday party. Not as heavy as an LP tank, but plenty stout enough. Angle grinder along the weld seam, set on the turkey frier, and pour on the heat.

[Shiloh]

Saw a BBQ/smoker made from an old odd-ball sized one. He said they were no longer filling that kind.
Did it with a grinder and welded hi,self up a nice smoker on a trailer. How many Sawz-All blades would it take to do one??

Shiloh

[CastingFool]

Yep, I used an empty helium tank from the kid's birthday party. Not as heavy as an LP tank, but plenty stout enough. Angle grinder along the weld seam, set on the turkey frier, and pour on the heat.

that's what I use, too! but no on the turkey frier. I use the auxiliary burner on our BBQ grill.

[bgokk]

Saw a BBQ/smoker made from an old odd-ball sized one. He said they were no longer filling that kind.
Did it with a grinder and welded hi,self up a nice smoker on a trailer. How many Sawz-All blades would it take to do one??

Shiloh
If you are inquiring about cutting an LP tank I used only 1 and it is still in fair shape.

Just don't put pressure on it let it do its thing.

[fastfire]

I have welded on gas and diesel tanks while working at a machine shop.
We backed up the service truck to the tank and ran a hose from the exhaust to the fill opening.
Any ventilation holes need to be open at this point. Run the exhaust in the tank for about 5 minutes and start welding or cutting then.
The exhaust replaces the oxygen.
Fire needs fuel, oxygen and a spark source, take any one of these away and you do not have a fire.

[geargnasher]

Those valves can be a buggar to get out. You can fill the tank with water by holding a hose to the outlet and opening the vent. Once it's full of water you can drill a hole safely. Once you get a hole in it it's easier to drain/refill a few times, which will ensure no poof unless you use a plasma cutter like I have. Some residual flammable stuff can hide in the black mercaptain that settles to and sticks to the bottom of the tank, and if you only have a small hole when you start blazing, it can get your attention very quickly when it cooks off. Using a jigsaw or recipro-saw with metal blades likely won't set that off and one good water fill/drain should be plenty to make it safe to cut.

The secret to making a propane tank melting pot work is a powerful head source (cone-ring style turkey fryer burner or blower-assisted wood fire) and a windbreak made out of some galvanized roof flashing. A lid also helps. All that said, a heavier, STEEL pot (not cast iron or aluminum) is better than a thin one.

Gear

[MT Gianni]

Put a good sized pipe wrench on the bottom base and use a tight fitting tool to pull the valve. IME, grinders spark more than jig saws r arc welders. When ever we were welding in a field the grinder sparks were more likely to start something than arc welding off a vise on the back of the truck. We manned an extinguisher and had a person watching, you should not need to until hot weather. I like exhaust to clear a tank, it is tough on a smaller one like LP 20# tank. Invert it for a day, fill with water and rinse several times then cut.

[mpmarty]

Our dump won't take old propane bottles unless they have a hole in them. i've disposed of two of the old style by "venting" them with my 45/70.

[Forrest r]

I used a sawsall to cut the valve off of mine, left 2 small holes. Filled the tank with water through them & used a 4 1/2" angle grinder with a thin cutting blade.

If you cut just below the weld line using it as a guide, you'll end up with a clean straight cut & the support ring will stay on the top 1/2 of the tank. That ring makes a nice tight fitting seal & helps hold the lid in place. I only melt down 100# of range lead @ at time in mine using a turkey cooker base.

95469

forrest r

[DRNurse1]

I have a DCrocket tank half. Only modification was using a drill to cut holes in the rim for a bail. I hang my pot on a chain over a arebar tripod to prevent spills. How can you spill 200# of molten lead/ alloy? ..... I wish I had photos of how much of my driveway that covered. took me a day to re flux all that lead.

[4rdwhln]

Hi there, everyone.In my youth I worked for cenex,and must have filled about a million of the 20 lb lp tanks. We also did the hydro_static testing of tanks and recertification . And I changed quite a few valves. We used to chain them to a bit I beam in the warehouse with a load binder as tight as we could get it. We had special wrenches for the valve and several cheater pipes to about 6 foot. And I am here to say even then there were times the valve won. Anything that was not serviceable was filled with water and left over winter in the yard. If you open the vent tube, screw driver slot usually it will vent the air till you get to 80% of tank capacity then it gets slower filling. By spring they had froze and had cracks through the side. A person might try them out for a source of out of date tanks. they should sell for cheap. Also use gloves when you are working with an old tank,IF THE NASTY smelling go from inside one gets on you your missus will not let you in side for a week till it wears off. Never did find anything that would kill the smell or get it off.. Also a safety note lp boils at 50 bellow and can freeze ya in a heart beat.. always fill with thick rubber gloves never leather or cloth as these can freeze to you.. ben there done that wasn't as much fun as one would think.
I am small time compared to most of the people at this forum, I cast with an old 3 pound bottom drop pot with and old soldering iron thermostat wired to it. I smelt in an old stainless soup pot over the barbq side burner.. It holds a little over 20 lbs. I try to smelt in the fall after it starts staying around 40-50 degrees in the day..I user to use the old coleman camp stoves but I either killed mine or it just didn't have the heat for the conditions and quantity of lead. the side burner works much better.

[blackthorn]

Twenty lb tank, anchored solidly. Large cresent wrench with long pipe over handle. Remove valve (may need to et wife to pound on wrench/hanle with hammer). Fill tank with water. Take 4 1/2" angle grinder and cut good sized square hole around valve opening. Dump water, lay tank on side and cut off just below shoulder. Cutting the tank there leaves you plenty of room to fill tank with WW. I got fancy with mine and had my kid weld two large steel washers on opposing sides of the tank. The holes in the washers will accept a 1" steel bar so the tank can be supported on "jack stands" to help suport the weight. He also shaped in a pour spout and made a lid. Works really well.

[Firebricker]

Don, What area do you live? FB

[MT Gianni]

The folks that haul merco-captan, odorant for Natural gas and LP use bleach to neutralize it. If that would ruin your clothes sunshine is your only other alternative. Bathing in 5% bleach water cuts that odor.

[jeepyj]

When I built mine I brought the twenty pounder it to the pit blasted a hole the top half with my 357. Brought it home and filled it with water then used a 4 inch cutoff wheel to cut it around the middle seam. Then I used a flap disk to smooth up the edges. No special valve wrench required. Burned It out and threw the top half in the scrap pile. It is the best bulk smelter when used with my old turkey cooker I could ask for!
Jeepyj

[dverna]

Firebricker,
I live east of Gaylord Michigan.

Guys,
Thanks again for all the good info. I am leaning towards buying a steel pot. I plan on smelting range lead only - maybe 250-300 lbs per year. If I can handle 75 lbs at a time that is plenty. I can do all my smelting in a day - 4 or 5 pots. 200 lbs of alloy in a pot supported by a turkey fryer sounds a bit risky to me so even if I had a large pot I would not fill it.

Again, appreciate everyone sharing their ideas/experience.

Don Verna

PS: I should not show how ignorant I used to be - but I used to smelt range lead in my Lyman 20 lb casting pot. I know it is a no-no. Older and wiser now.

[fryboy]

i wouldnt say it's a no-no as it can be done , but one has to clean the pot a bit more often , it is nicer when one doesnt do it but ...

95575

as for a metal sawzall blade ( it's better than a multi purpose bi-metal blade ) the going slow part helps as does lubing the blade now and again , even paraffin can work or oil , if one doesnt hold the foot down it'll sure jar any fillings you may have in your teeth loose , the above foto was a free freon tank i picked up at the landfill , they couldnt bury it etc so i asked if i could have it ( obviously this helped them and me eg;win-win ) my hunting buddy now uses and for some reason is so keen on it he wire brushes the outside clean after every use , the thing darn near gleams , even tho i left the holes for the handle ( had planned on using 1/4" rod ) it ended up with a re-purposed ( and modified ) 5 gallon bucket handle ( an older thick one from back in the day when metal was metal )

[jmort]

Happened to get propane from local seller today and asked him about the valves, if the were reversed threaded like the hook-up. No he stated but said they are difficult to remove. Long story short, he replaces them in a valve replacement tool/jig/vice-band/contraption which his grandfather fabricated. Looked real handy and said he would remove mine for free. How nice is that! Soon I will have another smelting pot for my collection.

[jeepyj]

The valve remover that a fellow had that I had the opportunity to have a look at was simply a 8 inch piece of heavy pipe with a slot cut into it so it fit securely around the valve. He used to chain the tank to prevent it from spinning and slid the homemade tool down over the valve then put on pipe wrench with a long extension handle on. They come out very hard. That's why I opted to simple blast a hole in it. I also have shot a couple others because the scrap yard won't take them without a hole in them.
Jeepyj

[butch2570]

Ok, i am a welder of 23 years and i am seeing information here that has the potential of injury , you may get LUCKY and do some of these things 100 times and 101 BOOM.. THE notion that any tank that has flammable liquids in it ,can be filled with water and it will be 100% safe is FALSE water is H2o-- OXYGEN is a part of the make up. Many a men has been hurt because of this idea. Explosions have been documented on WATER filled tanks thought to have been safe. Get the valve out ,yes, drill holes in it, shoot it ,take a old ax or splitting maul and knock a hole in it , set it on a hot fire along way from endangering something as long as you have some vent holes already in it, fill it with INERT welding gases argon,co2,75/25, exhaust from a engine . Eliminate one side of the fire triangle is the way to go for sure but water in the tank is NOT the safe way to do that.

[codgerville@zianet.com]

Ok, i am a welder of 23 years and i am seeing information here that has the potential of injury , you may get LUCKY and do some of these things 100 times and 101 BOOM.. THE notion that any tank that has flammable liquids in it ,can be filled with water and it will be 100% safe is FALSE water is H2o-- OXYGEN is a part of the make up. Many a men has been hurt because of this idea. Explosions have been documented on WATER filled tanks thought to have been safe. Get the valve out ,yes, drill holes in it, shoot it ,take a old ax or splitting maul and knock a hole in it , set it on a hot fire along way from endangering something as long as you have some vent holes already in it, fill it with INERT welding gases argon,co2,75/25, exhaust from a engine . Eliminate one side of the fire triangle is the way to go for sure but water in the tank is NOT the safe way to do that.

Absolutely right.

[dverna]

Ok, i am a welder of 23 years and i am seeing information here that has the potential of injury , you may get LUCKY and do some of these things 100 times and 101 BOOM.. THE notion that any tank that has flammable liquids in it ,can be filled with water and it will be 100% safe is FALSE water is H2o-- OXYGEN is a part of the make up. Many a men has been hurt because of this idea. Explosions have been documented on WATER filled tanks thought to have been safe. Get the valve out ,yes, drill holes in it, shoot it ,take a old ax or splitting maul and knock a hole in it , set it on a hot fire along way from endangering something as long as you have some vent holes already in it, fill it with INERT welding gases argon,co2,75/25, exhaust from a engine . Eliminate one side of the fire triangle is the way to go for sure but water in the tank is NOT the safe way to do that.

It just confirms my decision not to cut a tank up. it is not worth the effort or risk to me. I will try finding a steel pot at Goodwill or Sally Ann or pay less than $50 for a pot at Wally World. I would rather spend my time smelting or casting than fabricating a pot or spending time in the emergency room.

Thanks again to all for sharing their experience/knowledge.

Don Verna

[cheetah]

'Here, hold my beer, I'll show ya how."

[MrWolf]

I picked up two propane tanks from my local garden center - they charged folks $5 to dispose of and gave me as many as I wanted for free. A couple of months ago I took the valves off them by first making a 50/50 concoction of acetone and tranny fluid as a thread lubricant. Put this on for a few nights running. I then used a plastic dead blow hammer and kept hitting the valve till it unthreaded. Filled both tanks with water for a few days the turned them over and let them sit - forgot about them for awhile. A month or so later and as soon as the weather gets warmer, I will cut them for my smelter - one for COWW and one for SOWW :wink: I had originally grabbed four tanks. I have already swapped one for a good filled tank at one of those gas station centers. Tanks were originally turned in as valves were old style.

[StromBusa]

Whatever you guys do with pressure tanks, be very careful of pressure. I worked with a guy that his father was killed when an oxygen tank fell over and the valve was knocked loose & went through his head. LP tanks offer pressure, cold & potential fire & explosion risk let alone skank stink...That is why tanks have shields around the valves, and need to be secured against tipping. They can freeze up & not completely empty, however appear so. I'd shoot it & burn it. All from a distance.

[Sgtonory]

Here is a link to my setup i use. http://www.youtube.com/watch?v=CD5NIVG0iO0