warping question

[simplexcoda]

Ok. Im sure you guys think this is going to be about fixing a warped door. That is not what this is about. I have had a 120 gallon propane tank that I have been going to use for a reverse flow for a while now. I was wanting to cut it from 7 feet down to 4 to lighten it up. I have been holding off on cutting into it until I have all my materials. But, I am about to move out of town and i have access to a tractor where I live now to load the full tank up, but I wont where I am moving. So I was thinking I could go a head and cut it down so I could load and unload it easier. So my question was.....if I were to cut it down now would the tank warp before I go to building it? If so does anyone have any suggestions for loading and unloading easier?

 

[bubbonehead]

I don't see that being a problem. I did the same thing to a 250 gallon tank when I built mine. The only way that it would change once it's cut would be if it got damaged during that time. The warping that does occur when cutting these tanks is a combination of two things, the most obvious being the heat produced during the cutting process. The other being metal memory which is basically trapped energy that's been there since the formation of the tank. What method do you intend to use to cut your tank?

 

[simplexcoda]

My plan was to fill it with water since its an old propane tank and then cut the end off with a grinder.
 

 

[bubbonehead]

Good, the water will help with the heat issue. That's how I cut mine also. To keep as much water in the tank as long as possible, Make both cuts in steps alternating from one to the other every few inches. Don't forget to put dish soap in the water when you fill it to help displace any gas. As your cutting you'll still smell propane from time to time that is trapped in the steel itself. It won't last long. Just long enough to make you think "do I smell gas?" and then it's gone.

 

[simplexcoda]

Yeah, This will be my first time cutting a propane tank so Im a bit nervous. But I dont forsee and issue if I do it nice and safe.
 

 

[daveomak]

Coda, evening.... Cut off the two round ends, add legs, and sell them for outdoor fire pits...  make some bucks to offset the expenses... they make a my-t-fine fire pit....   Dave