Cutting into a propane tank

[merc_man]

I am gonna be making a homemade smoker and looking for some safety tips for cutting propane tanks open.
so i have had this tank for just shy of 2 years. Day i got it i popped the cap out so it could air out. Last weekend i filled and and drained it with water to rince it out. So my next step is to cut into it...
So do i fill again with water then cut while full?
Or i also read that you can use exhaust fron an engine to purge any left over gas out as well while cutting.
So for cutting i would prefer to use the plasma cutter but maybe not a good idea if water was inside unless using tje eshaust method.
Can also use a grinder if the water way is safer.

Thanks for any advice.

 

[Mack 880]

Fill with any inert gas and then cut away. Water is messy

CO2, Nitrogen, exhaust (as long as it's completely used up and an inert gas and has no combustibles)

 

[Yukon Stihl]

Turn it upside down when you take the valve off.
Propane is heavier than air so it will leave the tank.

 

[Yukon Stihl]

I made storage tanks for my heating system from 500 gallon propane tanks.
Cut holes in them and welded extra bungs for piping.

 

[Junk Meister]

An Old guy told me if you can't smell it it can't burn. I usually rinse with hot water and dawn dish soap. . I did a bulk gas tank that had gas in it, I used car exhaust ( an old smoker Chevy wagon I was selling a friend for a demo derby) and let it run an hour or so. Torched the door opening and left. The owner was going to use it for feed storage. He told me the sediment was a foot deep (Upright tank) and reeked of fresh gasoline when he broke the crust. Leaded gas doesn't sour as fast as todays gas. I did this in the early 80s'. Never liked the thought of all that smell being in there when I torched it. Some serious blessings from above that day.
P.S. the old guy (Ron Simmonds) died of old age and he repaired a bunch of gas/fuel tanks in his life.

 

[Da dog man]

As above stated water will make a mess but if it's what u got will work. Wouldn't recommend cutting it while water is in it though.

 

[merc_man]

Turn it upside down when you take the valve off.
Propane is heavier than air so it will leave the tank.

Yes i did do that. Its been upside down the whole time.
Thank

 

[merc_man]

As above stated water will make a mess but if it's what u got will work. Wouldn't recommend cutting it while water is in it though.

Ya i was thinking water may be bit messy.
Leaning.twards trying the exhaust piped into it method. Let it run in ther for a half hour or so and cut it.

So once i get a chunk cut out it is pretty safe after that?

 

[bucketofguts]

What kind of smoker are you going to build?

 

[odin]

...i filled and and drained it with water...

This is your answer right here. If you fill a container with water, then it is impossible for there to be any gas (flammable or otherwise) left in the container. This is the reason behind the practice of filling an old propane tank with water (and then draining it back out again) before cutting it open. The water is a readily available forced purging agent. Unlike inverting the tank (which does work, by the way), water is visible, and fast.

Double rinsing and the use of odd additives like soap are used by folks who are missing some knowledge of rudimentary physics. All you need is enough water to fill the tank... glug, glug, glug...

 

[merc_man]

What kind of smoker are you going to build?

Gonna build a stick burner. I picked up an old wood stove to use as the fire box.
Not sure if im gonna do the 6 inch exhaust just out the side or make a collector box for it yet. May do just outthe side and if it works good like that then roll with it. I i think it may benafit from a collector then i can always switch later.

 

[Eakf]

I built a 250 gal offset a few years ago. Did a collector and an insulated firebox. It works really well and doesn't burn much wood for the size.

When cutting your doors, leave the corners in place, and get your hinges on first. It'll make it much easier.

The woodstove may not have a big enough "throat" to the cook chamber, and you may struggle with temps and dirty smoke. If you search for Dave Omak's calculator, it's got all the tested formulas. If I recall, my firebox to cook chamber opening is about 230 sq inches for the 250 gallon cook chamber.

I used 3" of rockwool on the firebox, and you can touch it with a bare hand while in use. All the heat going into the cook chamber.

Happy to answer any questions you might have, I spent a lot of time designing it based on a few commercial units in town I got to look at along with the calculators.

 

[Hinerman]

I built a 250 gal offset a few years ago. Did a collector and an insulated firebox. It works really well and doesn't burn much wood for the size.

When cutting your doors, leave the corners in place, and get your hinges on first. It'll make it much easier.

The woodstove may not have a big enough "throat" to the cook chamber, and you may struggle with temps and dirty smoke. If you search for Dave Omak's calculator, it's got all the tested formulas. If I recall, my firebox to cook chamber opening is about 230 sq inches for the 250 gallon cook chamber.

I used 3" of rockwool on the firebox, and you can touch it with a bare hand while in use. All the heat going into the cook chamber.

Happy to answer any questions you might have, I spent a lot of time designing it based on a few commercial units in town I got to look at along with the calculators.

Got any pics of your smoker?

 

[merc_man]

I built a 250 gal offset a few years ago. Did a collector and an insulated firebox. It works really well and doesn't burn much wood for the size.

When cutting your doors, leave the corners in place, and get your hinges on first. It'll make it much easier.

The woodstove may not have a big enough "throat" to the cook chamber, and you may struggle with temps and dirty smoke. If you search for Dave Omak's calculator, it's got all the tested formulas. If I recall, my firebox to cook chamber opening is about 230 sq inches for the 250 gallon cook chamber.

I used 3" of rockwool on the firebox, and you can touch it with a bare hand while in use. All the heat going into the cook chamber.

Happy to answer any questions you might have, I spent a lot of time designing it based on a few commercial units in town I got to look at along with the calculators.

Thanks for the advice. Did you use homemade hindges. I was thinki g of making a set myself.

For the stove part i was gonna block off the chimney and cut back of stove out.
Do you have any pics of yours?

 

[Junk Meister]

II think I will watch this thread and see if it morphs into a smokin' thread.

 

[chipper1]

II think I will watch this thread and see if it morphs into a don't try this at home thread.

 

[Eakf]

Please excuse the less than pretty welds.
6' ladder for scale. Used a 24" 3/8" wall pipe for the firebox liner, it's about 42" long. Easy to move fire forward or back depending if you want even heat on the grates, or a hot spot on one end.

About 4-5 splits to get to temp, then one every 45 mins or so once it's got a coal bed.