Welding my oil tank evap

[bigjohnsons]

I am new to welding, this is my first project and today I cut the top off of the tank and cleaned out the sludge/oil. I wiped the inside down with rags etc.
Question: Is it ok to start welding the tank or should I take it outside and burn it out before I weld.

I was planning on burning it out but than I ended up going a little crazy wiping it down with rags and I was hoping to start the welding tomorrow night after work.

Thank you for any advise.

[TonyL]

You're going to want to burn it out sooner or later, and if it were me I would burn it now, before any further fabrication takes place. Right now it's just a big open topped tank....doesn't get much easier than that.

[Machinist67]

I would agree to burn it now so you do not have problems with perocity in the welds.

[WESTMAPLES]

I built a few thing out of 275 gal oil tanks. I did scoop the sludge out and I would cut up 1 or 2 pallets and burn it hot for a few if you get it too hot for a long period it will warp bad , wavy most of the time good luck oil tanks make good small inexpensive arch

[optionguru]

I burned mine out before doing much to it. The only thing I would do is weld in a cross brace of angle iron before burning it out. When I cut the top of mine the sides bowed out a couple of inches. I think this would be even worse when you get it hot.

[woolermaple]

I just started building a 9 foot arch out of an oil tank today, I cut it in half and burned out the sludge and oil with no issues and warping. got hot enough to burn the paint off the outside of it.
-I will post pictures on this site when I am done i got a lot of info off this site looking at old threads, was a lot of help.

[CincySyrupPusher]

Good luck on the build! Hope you get it done before the sweet starts flowing hard.

About to tap here in SW ohio!

[bigjohnsons]

Well my tank/arch is coming along nicely, alot more time consuming than I thought, but alot fun. This is my first time welding and I am learning on the job. Where the angle iron meets the top of the tank, I am having problems welding it up to be airtight.
Question, is the anything that I can use to seal up the tank to make it airtight, like a mastic or something? I am running out of time and the weather is supposed to break at the end of this week and the sap will be flowing.
Thanks in advance for any advice.

[lpakiz]

There is a compound, like putty, that is called furnace cement. It comes in a can or a tube for your caulking gun. Made just for this purpose. Hardware store, big box farm store.

[optionguru]

I'll second the furnace cement. Mine came in a pint size tub. I welded about 1/2 the length of all my seems and then filled the rest with the cement. Worked great.

[Wood burn]

Are you welding with a mig? If so you need to weld that joint virtual down and you shouldn't have any problems set the machine to about twenty volts good luck .