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cleaning rusty oil tank

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Post Fri Nov 19, 2010 5:43 am

Posts: 162
Location: athens,greece
Hello again,got given i nice OEM 40`s BT oil tank that some one had dechromed at some point and left on the shelf....
result being,light rust inside and out....anyone have any good easy way to clean this inside before painting.....can put in petrol and some old nuts and shake for a while,but is there any easier /better ways......thanks.....

Post Fri Nov 19, 2010 7:30 am

Posts: 377
Location: madison wisconsin usa
you might try this method. ... usting.htm

i used it to clean the inside of my wla fuel tank. i had to fashion an electrode out of a piece of bar stock fitted through the filler opening. worked like a charm! all you need is a pail, water, washing soda and a battery charger.

be forwarned! this process produces hydrogen gas! do it outside, well ventilated, no smoking etc.


Post Fri Nov 19, 2010 7:39 am

Posts: 3159
Location: Central Illinois, USA

I wouldn't use petrol; shaking the tank with objects inside could cause a spark.
Aquarium gravel and Simple Green is my favorite abrasive for getting the big chunks out, although I use a tumbler:

Then, muriatic acid works quite quickly, and if followed immediately with baking soda to neutralize it, and finally WD-40, the immediate 'flash' of new rust should be minimal.

Please take all safety precautions with the acid, and beware of capping the tank tightly for the neutralization step, as a great deal of gas is produced.

Citric acid is a much safer alternative, however it takes much longer.

Good luck!

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Last edited by Cotten on Fri Nov 19, 2010 7:43 am, edited 2 times in total.

Post Fri Nov 19, 2010 7:41 am
Pa Site Admin

Posts: 5843
Location: Ohio USA

Fill it full of white vinegar and let set over night. For light rust, that will do it. empty.... Clean with hot soapy water, rinse well. When storing, add oil and slosh it all around to cover every inch of the interior.

Post Sat Nov 20, 2010 12:18 am

Posts: 1038
Location: Ojo Caliente,NM,USA
If you follow the reverse plating directions at ... usting.htm
Don't use stainless steel as he recomends. I know its a pain replacing the steel rods every few weeks but some stainless steels will release Hexavalent Chrominum nasty shit and highly illeagle to dump! I used 10 guage c channel last tine and it didnt last 2 weeks, gotta find some more rebar

Post Sat Nov 27, 2010 2:12 am

Posts: 162
Location: athens,greece
Hello again,thank you for all the great answers.......interesting stuff....will try with white vinegar firstly and see from there...........

Post Sat Nov 27, 2010 9:42 am
Pa Site Admin

Posts: 5843
Location: Ohio USA

Don't leave the white vinegar in to long. Keep a close eye on what is is doing. It wil slowly kind of boil the rust to the top opening, leaving an odd looking formation of crusty foam. If you must, dump it all out so you can inspect what is has done for you. If not good enough yet. Pour it all back in and give it more time to work on the rust. When you are satisfied with the results, be sure to wash it out with the hot soapy water and then rinse well. Also preserve with motor oil or the like. Oh yeah......remove all traces of oil before using the vinegar.

Post Sat Nov 27, 2010 4:35 pm

Posts: 2688
Location: Los Angeles, CA
Once it is clean don't forget to put a coat of oil in it.

Post Sat Nov 27, 2010 6:11 pm
Pa Site Admin

Posts: 5843
Location: Ohio USA

Chris Haynes wrote:
Once it is clean don't forget to put a coat of oil in it.

Duh Chris...Ain't that what I said ? LOL

Post Wed Jan 12, 2011 9:58 pm

Posts: 66
I have had mixed results with electrolytic cleaning. It works great at first but seems to do less the longer it runs, so you never really seem to finish. Also, it leaves a pervasive black iron oxide residue, that must be scrubbed off or pressure washed off. Seems I end up beadblasting most of the things I electrolytically strip to get rid of the residue, but if the part is really cruddy the electrolytic stripping first can save a lot of blasting.

Oh, the anode should ideally be as large as the area being stripped/derusted. Not usually possible with a tank, but the more anode you get inside the better. Also it works line of sight, the anode must "see" the area being stripped.

For light rust phophoric acid/surfactant mixes from the hardware store work well. Phosphoric acid, unlike many others, won't attack good steel. Problem with slower acting acids is they end up taking so long you forget about them, and come back and find the part all rusted or eaten to hell.

Sometimes when you got just one part the easiest way is to take it to an automotive machine shop and have them hot tank it.

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