Propane Tank Pots - Cut Above or Below The Seam?

[Jon]

I have a couple of 20lb propane tanks that are ready to be cut. Do you guys recommend cutting below the seam for smoother sides, or above for more capacity?

Any tips on a smooth cut, and making a line around the tank? I plan on using a dremel cutoff wheel to start, and finish with a jig-saw.

The valves are out, and they have been filled with water to push out any possible propane remnants.

[DougGuy]

You would be better off using a 4" grinder with .045" cutting wheels. Cut up near the top, measure up from the seam until you get to the start of the curve, and keep your cut in the straight part. Measure up from the weld and make a small mark with a sharpie pen every 3" or so around the tank, then use an old sanding belt or something straight that will bend around the tank, align it with the marks you made and mark a solid line with the sharpie. Cutting this with a 4" grinder and cutting wheels will look like a razor got hold of it, if you don't hurry and you keep the wheel from binding and grabbing, it will look nice. No need to cut at the seam, that just wastes half the bottle.

[D Crockett]

take a sharpie and a piece of 1x2 piece of wood use that to make you cutting line using the wield in the center of the tank for a guide I would cut above the tank wield line I would use a side grinder with a 4 or 4.5 in metal cutting blade in it just be sure that the tank is purged enough to get all the gasses out D Crockett

[Jon]

Thanks for the tips guys. I did fill them with water to get all the propane out. They do have that lovely odorant smell though.

[BeeMan]

Just below the seam will give plenty of capacity. That much molten lead needs substantial support for safety's sake. Grind a starting slot, cut with a jig saw or sawzall, and dress up the edges with an angle grinder to get a very functional pot.

[kayak1]

Cut above the line, Then you can use a C clamp to make a temporary handle. The seam will prevent the clamp from sliding off.

[dikman]

Co-incidentally, I just cut one today. I cut below the seam (about 1 1/2", I think) as I don't want it too big (for stability). I intend to bend some heavy steel rod to make a couple of handles to weld onto the sides. I still have the top half to make another one if for any reason I need a taller one - it's only a matter of welding up the valve hole. I fitted a strap around it and used that as a guide to mark around it and cut it with a 4" angle grinder and a thin cutting wheel, which worked well. (I'd just finished cutting when my grinder started making funny noises - it is over 30 years old! - so I pulled it apart and the front bearing had disintegrated!! Fortunately, I found the right size sealed bearing in my "bearing supply" and managed to get it working again).

I remembered that I have a portable hand-cranked forge buried away in the back of my forge, so I've decided to modify it to support the propane pot and use an old hair dryer for the air feed. I can then do my smelting outside.

I love this shooting, there's always something new to make :smile:.

[detox]

I wrapped tape around tank and used tape edge as guide when cutting with cutting wheel...you better have a good air compessor. A jigsaw should work also. I cut above the seam then cut another piece to guide flame better. I also added a 5 gallon paint bucket handle (remove plastic). I have smelted over 200lbs at one time in this setup.

[wrench]

I cut above the seam, added a homemade wire bail handle, a little stop to keep the handle out of the flames, and then heated and bent a pouring spout.
Works fabulously well, and you can't beat the price.
I think I used a sawzall to do the cut, and just eyeballed an even line with a sharpie marker. Clean up the cut edge with an angle grinder, voila!

[Salmon-boy]

On or just above the seam will still leave a container very heavy when full of lead.. I know it's frikkin heavy when less than 1/2 full of portland cement/perlite mix.. If you're going to scoop with a ladle, make sure to have enough support for the entire volume..

Pull the valve, fill with water and empty before cutting, however you do the cutting..

The bigger you go, the more insulation you'll want to have around it.

[dikman]

Salmon-boy, that's exactly why I cut mine on the low side - so I can't over-fill it!

Wrench, that's a real witch's brew you've got cooking there!!:lol:.

[country gent]

Use a belt or hose clamps to get a straight true line around the tank where you want it. I really recomend non spark cutting for saftey, but then Ive been "bounced by a drum cutting it open one time. Where you cut it depends on the volumne you want. Also a ring from the old tank longenough to make a "stand is much more stable than the one under it. Can be welded at 4-6 plaes around the tank easily. This will help to hold heat and make a very stable base. Im going to cut one with about 3" side walls for a casting pot. Im thinking it will hold around 100 lbs and be a shallower pot making fluxing a little easier.

[dikman]

My version of a propane pot, sitting on a portable forge. This will let me do it outside. The pot is the bottom half, walls about 4" high, handles are bent from re-inforcing rod and I heated the edge of the pot and hammered in a pouring spout. (While heating it I noticed how tough the paint finish was on it, possibly epoxy paint. I originally intended to just burn it off, but decided it was better to sand it off with an angle grinder).

The frame that the pot is sitting on is welded from more reo rod (3/4" across the top) and should easily support the weight. A hair dryer fits in the pipe at the rear, with a butterfly valve to control the airflow. Should be enough air to keep the coke burning without getting too hot.
At least, that's the theory. I'll try it out next week.
8600686007

[geargnasher]

I cut mine just below the top shoulder to make it as tall as possible. The specific reason for doing so is that even 75 lbs of clippy wheel weights has a LOT of volume before melting, and since I don't particularly like the idea of dumping anything cold and potentially damp into a pot of hot lead, I can do a lot more WW from a "cold start" than I could if I had made the pot shorter.

Just because it's tall doesn't mean you have to put 200 lbs in there before pouring ingots.

Gear

[jm423]

I'm about to cut an old Freon tank to make a smelting pot, had decided to cut just above (adjacent to) the weld to have sort of reinforcing bead at the top, also to round over eliminating sharp edge. Now you guys have me pondering--at, above, below?? Think I'll just go ahead as planned. Like the bail, hadn't thought of that. Thanks for all the food for thought!

[dikman]

Tried mine out today, and it worked very well. The forge and blower performed better than I expected, with plenty of heat available. Only one minor problem....if I stirred the lead too vigorously while fluxing it started to slop over the rim!! I think tall sides are probably a good idea!

[thehouseproduct]

Just don't cut on the seem like I did. It is quite a bit thicker.

[Jon]

Just don't cut on the seem like I did. It is quite a bit thicker.

I found that out as well. A half inch would have saved quite a bit of cutting time. A sawzall works great though.

[JASON4X4]

I made one out of a freon tank and cut above the seam. I welded Handel's on it and have smelted just over 1000 lbs it works greqt

[dsbock]

I know I'm resurrecting an old thread, but I just cut my first tank last week and thought there might be some interest in my method.

After removing the valve and purging the tank with water a couple of times, I left the tank propped upside down overnight.

I used a 10" metal cutting wheel on my table saw. Laying the tank on it's side and using the fence to guide the base ring, I rolled the tank against the blade over and over until it cut through. I cut just above the weld so as to have added support at the top of the pot. After the top of the tank was removed, I used my angle grinder to smooth and bevel the resulting edge. I then repeated this procedure to cut a ring for use as a base support.

During this entire procedure I wore a full face shield and hearing protection. After the first few seconds of cutting I stopped and added a hat.

My next step will be to figure out some type of handle.

117600

David

[Mike W1]

Think I'm gonna shorten mine to below the weld as it'd be easier to use my dipper which is the way I have to get it out of there. An extra inch of liquid lead in a 12" cylinder adds about 46 lbs to the pot. I'll leave some height above what I figure is about the 150 lb level. Fired it up just to melt down some old lubed bullets today. Glad I have an exhaust fan that really sucks air. Couldn't see in the pot for a few minutes till I got the floating lube spooned off. But it's sure shiny metal!

[stanford]

David,

Thanks for posting this as I am very interested in making something to smelt and clean up lead. Would also like to have some sort of bottom pour
spout added.




I know I'm resurrecting an old thread, but I just cut my first tank last week and thought there might be some interest in my method.

After removing the valve and purging the tank with water a couple of times, I left the tank propped upside down overnight.

I used a 10" metal cutting wheel on my table saw. Laying the tank on it's side and using the fence to guide the base ring, I rolled the tank against the blade over and over until it cut through. I cut just above the weld so as to have added support at the top of the pot. After the top of the tank was removed, I used my angle grinder to smooth and bevel the resulting edge. I then repeated this procedure to cut a ring for use as a base support.

During this entire procedure I wore a full face shield and hearing protection. After the first few seconds of cutting I stopped and added a hat.

My next step will be to figure out some type of handle.

117600

David

[dsbock]

Stanford,

You're quite welcome.

If I was going to cut a tank for bottom pour, I'd try to figure out some way to use the valve opening on top. Flip the tank upside-down and use that as the bottom. Weld a section from the middle of the tank as a support and go to town. I've seen several designs in this and other threads.

Good luck and don't forget to post pictures when you're done.

David

[stanford]

David,

I thought about this but it seems like if you use the valve as the spout it will be directly in the flame since it sits in the middle of the tank directly in the fire. I saw a youtube video one time of someone casting ingots outside in a very large drum like pot. They had a spout along the side close to the bottom. I guess I will have to see a pic of how someone added a spout, it's not registering with me at the moment.

[DukeInFlorida]

I always cut mine 1" above the seam.
The image shown here: http://castboolits.gunloads.com/attachment.php?attachmentid=85733&d=1370987160
Looks to be about what mine look like when done. The bottom band is about 3", and is cut from the top of the tank.

Here's the bottom line:

1) Mark around the circumference of the tank, ONE INCH above the welded seam, which is mid tank.
2) Mark three inches above that line
3) Cut the top most cut first. You won't need that piece of scrap.
4) Cut the second/lower cut next. That will give you a three inch wide band. That gets welded to the bottom of the curved part of the remaining bottom of the tank. When done properly, the welded band should keep the original thin band on the bottom of the tank from touching your burner stand. You need the 3" band to assure stability when melting and stirring almost 200 pounds of 750 degree lead!

I'll get some pictures when my buddies and I smelt later this week.

Regarding the smell........... No need to fill anything with water......
Remove the valve, and turn the tank upside down for an hour or so. All the residual propane gas will be gone. Propane has no natural smell. per se. The companies add an "ONION" smell to the gas, just like they do with natural gas. That's so you can detect a leak. The onion oil gets into the pores of the steel, and makes you think that there is propane in there, when there really isn;t. Propane is heavier than air. So, after removing the valve, turning it upside down for an hour will assure that all the explosive gasses will be properly vented. IGNORE the smell. The first time you smelt lead, the heat will burn away the onion oil, and the smell will be gone.

[JRLesan]

Mercaptan is the gas that is added to various flammable gases to impart the odor...

[dsbock]

David,

I thought about this but it seems like if you use the valve as the spout it will be directly in the flame since it sits in the middle of the tank directly in the fire. I saw a youtube video one time of someone casting ingots outside in a very large drum like pot. They had a spout along the side close to the bottom. I guess I will have to see a pic of how someone added a spout, it's not registering with me at the moment.

Stanford,

The way I remember the designs, heat was applied by a ring and the spout went through the middle. It was more of a dedicated setup than most of us use.

I'll see if I can find some pictures.

David

[stanford]

David,

I saw a picture of a setup on here yesterday after you mentioned it. The burner was round and the valve on the tank fit in the middle of the burner. That would explain everything.

[DukeInFlorida]

The burner is a place where you could make a poor purchase.
Lead is extremely DENSE. It takes a LOT of btu's to get it quickly up to temperature, and molten.
So, the key is to get the "HIGH PRESSURE" regulator type burner. The btu output is MUCH higher than for the low pressure burner. The burner should sound like a jet engine if you get the right one. The cost ($$$) difference between the low pressure and high pressure versions is slim. It's always worth the little bit $$$ more to buy the high pressure one.

One that I like is this one:
http://www.amazon.com/Bayou-Classic-KAB4-Pressure-Cooker/dp/B0009JXYQY/ref=sr_1_3?ie=UTF8&qid=1415903669&sr=8-3&keywords=bayou+classic+propane+burner
It should come with a 30 psi regulator. btu output is 155,000 btu. Using the propane tank smelting pot, it will bring 150+ pounds of lead to a full melt in about 20 minutes. Roars like a jet plane while running full tilt.

[Lance Boyle]

Plus one to cutting 1" over or under the weld but not right next to it. I cut rather close to the weld and didn't realize I was cutting through two layers where the two halves are lapped before the weld. I hacksawed an entry slot and used a jig saw with a metal cutting blade.