Early Oil Tank Cleaning/Refurb

TC911e · 07-20-2008, 07:17 PM

Does anyone have suggestions for cleaning and repainting the oil tank on an early 911E. I'm slowing working my way through cleanup on a '69 911E I bought last summer. Has anyone got any good gimmicks for cleaning out the inside of the tank? There's some level of loose crude in there that I'm struggling to get out. Also, any suggestions beyond the typical Rustoleum type products for repainting the tank? This is the one behind the right rear tire and it's got some surface rust. I've done some searching of the archives, but haven't found anything that matches up very well.
Tim

Jagshund · 07-20-2008, 07:32 PM

There are many tank refurbishing kits available online, such as the HD Cycle Tank Repair Kit of POR-15, though most (such as that listed) if not all are geared towards fuel tanks. They generally have strippers, conditioners and sealers included; I have heard murmurings of the kits being used in oil reservoir applications but have no personal experience in the matter.

Flieger · Flieger's Garage

Make sure of the metals in your oil tank. 73s had copper lined steel tanks. I think earlier cars like '71 and earlier had just plain steel.

You don't want to inadvertanly use the improper solvent or cleaning procedure.

RWebb · RWebb's Garage

what do yo do if the tank has pinhole leaks in it?

304065 · 07-21-2008, 05:26 AM

Thou shalt not use any commercial tank refinishing products let thou destroy thine engine.

See the below thread-- a 911 oil tank, in addition to being an oil reservoir, is also an air/oil separator which reduces foam. As such it contains an internal mesh that will easily be plugged by slosh-type sealers.

Oil tank woes

The best course of action is to find a good tank and send it to Pacific Oil Cooler for leak testing, repair and ultrasonic cleaning. A "good" tank means one that hasn't had the top rust through like so many that have seen service-- over the years dirt collects above the tank and traps moisture which rusts the tank. Not that this can't be fixed, but it first must be absolutely clean.

A note about the tanks: these are steel and the factory dipped them in copper plating for corrosion resistance. It's just that simple, they are not made out of solid copper or anything. The plating could be sacrificed but you would need another good way to rustproof the tank, best to leave it alone.

Here are some before and after pictures of my tank which I sent to Pacific Oil Cooler. It has been modified by FABCAR for increased capacity and better internal baffling.

Carrerax · 07-21-2008, 06:10 AM

How much does Pacific Oil Cooler charge to do this? I took my oil tank out yesterday and Im trying to decide what to do with it. Same goes for my gas tank but I havent done a search yet.

304065 · 07-22-2008, 05:57 AM

Call them. www.oilcoolers.com

Sunroof · 07-22-2008, 11:09 AM

I just removed my oil tank from my 1973.5T and refurbished it. The best way to have these cleaned is at a radiator shop. They will boil the tank in a caustic solution as with their radiators. They specialize in this stuff. When I brought mine in I thought it was copper as the fittings were all copper and brazed onto the tank. It turned out the tank was actually steel both outside and in.

Below the oil filter fitting in the inside may be a metal meshed screen to catch large clumps of debris and this they cleaned carefully with a high pressure hose to clear the crap caked onto the screen. They can leak test the tank in a vat of cold water if you can provide an oil filter. Someone suggested Fram to save $$$$, but the filter will get soaked and wasted. I paid $40.00 for the cleaning and testing and they did an outstanding job.

Under no circumstances: DO NOT COAT THE INTERIOR OF THE TANK WITH ANYTHING!!!!!!!!!!!!!!!!!!!!! Once cleaned, leave the inside alone. I repeat, LEAVE THE INSIDE ALONE....................an interior coating can get loose and into your engine and mess up the works. If the interior of the tank is rusted and too far gone, I would rather look for another in acceptable condition.

The best exterior finish I found was POR 15. Flat, semi-gloss or gloss black would do well and only one coat is necessary, so buy the pint and you'll have alot left over for other stuff. My tank looks fantastic and should go another 35 years with any luck.

Good luck

Bob
73.5T

Carrerax · 07-22-2008, 11:37 AM

Thanks. Did the boiling in the solution remove all the paint also?

Mysterytrain · 07-22-2008, 01:05 PM

the paint looks great what is that?

Sunroof · 07-22-2008, 03:16 PM

The caustic bath will remove everything! I had a few pieces of sending unit cork gasket remaining but used my dremel brush to get it off later. Some folks recommend that its preferable to lightly sand the exterior before painting for better outer coat adhesion. This might help if you do not use POR 15, as this stuff will adhere to olive oil!!!!!!

I would call around to some radiator shops to check on prices and processes. Before they do anything they shoud look inside to insure the bath will not affect any interior component(s).

Bob