Rust in Oil Tank

[billpedalino]

I'm not sure if this is the correct area for this posting but here goes; I've selected the best horseshoe oil tank that I have for my '64 XLCH and like most, it has some minor rust on the inside. I will not abrasive blast it, especially on the inside. The rust is not too bad, as some areas still that I can reach with my finger appear to be a little oily. But there are some rust blooms on the bottom of the tank, as it was probably stored on its side without a top or plugs in the n.p.t. openings before I got it.

The way I used to remedy this was to place a significant number of clean nuts and bolts in the tank, fill it about 15% full with mineral spirits and shake it like mad - for a long time. This seemed to get most of the rust out...I think. It probably worked ok, as I never had oil flow problems after installing these tanks.

Does anybody know of a better way to remedy this (aside from bead blasting)?

Thanks....

[harleytoprock]

Hello Bill, I have used muriatic acid to clean tanks and if done correctly the metal will be as bright as new. Here's how I do it. Do this outside and observe all acid working safety precautions. Fill the oil free tank with muriatic acid. The acid can be bought at the hardware store and its inexpensive. Let it sit for about 20 minutes depending how much rust. Don't worry the acid won't thin out the steel. Pour out acid, flush with garden hose and then quickly fill with neutralizing solution( neutralizing is very important). The neutralizing solution I use is water with liquid clothes detergent and baking soda. Mix up a couple of gallons before you start doing the acid etch. Let the neutralizing solution sit in the tank for about 5 minutes and make sure its filled to the top. Now with the next step you have to work fast or the rust will come back right before your eyes. Dump the neutralizing solution, flush with water, dry tank quickly and quickly pour in some clean oil to coat inside tank. I also use the the neutralizing solution to clean the funnel, the outside of tank and any acid spills. To dry the tank I use my air blaster that is for drying bike after a wash. Sometimes I add a little heat with a heat gun. I've done this many times to gas tanks and oil tanks. Never use muriatic acid with aluminum. Wear gloves, face shield and a gentle breeze will help prevent breathing the fumes. Be carefull!

[Chris Haynes]

White vinegar does a great job in just a couple days and needs no neutralizing.

[vph-d]

I've used muriatic acid on gas tanks before to remove rust, and it really works. Next time though, I'm going to try the white vinegar. No "Dr No" clothing required, and no brain cells lost.
VPH-D

[Peter Cooke]

Somebody in another thread some time ago suggested a handful or 2 of washed gravel into the tank, wrap the tank with several layers of bubble wrap, put it in the clothes dryer (on cold) and let it run for as long as you think it needs.
Similar to your nuts & bolts and shake method but the dryer does the shaking.

[BoschZEV]

the best horseshoe oil tank that I have for my '64 XLCH and like most, it has some minor rust on the inside. ...

Since no one has mentioned it yet, add blackstrap molasses to your list of de-rusting chemicals. Seriously. Dilute it 10:1 with water and let it sit in the tank for a week. I've used it to de-rust at least three tanks over the years, plus remove the surface rust on several machine tools to leave a shiny metal finish, and it works great. In the end you're left with something as environmentally friendly to dispose of as you could wish for, with no need for acidproof goggles and aprons.

[harleytoprock]

Although vinegar( acetic acid) is mild, it is an acid and I would still neutralize. I tried Jack Daniels. Didn't work, so I drank the rest.

[Peter Cooke]

Since no one has mentioned it yet, add blackstrap molasses to your list of de-rusting chemicals. Seriously. Dilute it 10:1 with water and let it sit in the tank for a week. I've used it to de-rust at least three tanks over the years, plus remove the surface rust on several machine tools to leave a shiny metal finish, and it works great. In the end you're left with something as environmentally friendly to dispose of as you could wish for, with no need for acidproof goggles and aprons.

It's also supposed to be good for freeing up stuck pistons and such as well.
While were talking about acids and such, has anyone tried Coke? It cleans up old coins nicely.

[exeric]

Somebody in another thread some time ago suggested a handful or 2 of washed gravel into the tank, wrap the tank with several layers of bubble wrap, put it in the clothes dryer (on cold) and let it run for as long as you think it needs.
Similar to your nuts & bolts and shake method but the dryer does the shaking.

I've done that Peter. I used aquarium gravel (I prefer turquoise). It worked very well, with one very important caveat. Don't let your wife catch you defiling her dryer.

[Knotthed]

Coke works because it has Phosphoric Acid in it. Probably the best acid for cleaning metal if there is such a thing.

What ever you do, the oil will need to go to be effective - try some Dawn Dish Soap.

Molasses works off of something called Chelation. Chelation agent is commercially available as Metal Rescue. www.metalrescue.com probably not quite as cheap as molasses, but less messy and smelly in the long run.

[billpedalino]

Well, Looks like I'll start with the least aggressive and work my way to the muriatic acid. The metal Rescue looks interesting too.
Thanks to you all.