Gas tank revival

Biz · #1 01-20-2011, 09:29 AM

Lots of newbies on the forum, I'm one of them. Working on my '64 CA95 which was given to me.

My biggest concern when I got it was the gas tank - it was dreadful inside, must have been stored with 1/2 tank of gas sometime in the '70's. About 1/2inch of rust/crud/solidified crap in the bottom, stuff caked on the sides. Didn't seem to have any rust holes, thankfully. Did a lot of research on the web on how to clean tanks, lots of different techniques out there, so here's what I tried.

Started off pouring in a couple handfuls of roofing nails and some diesel fuel, got about 1/2 cup of crap out after several rinsings, but still a lot remained.

Next I soaked in vinegar for a few days. Not effective.

I really didn't want to use any chemicals such as muriatic acid that were toxic and/or would harm the paint.

I had just about settled on either the POR-15 or phosphoric acid (or both), then I read about the electrolysis method and, since I am an electrical engineer, I had to try it. Bought a 10A charger, some Arm & Hammer Washing Soda, some 3/16" and 1/4" threaded steel rod, and some cable sleeving at an auto parts store. First I make a blockoff plate to put where petcock mounts. Ended up going with about 4 tablespoons per gallon of warm water, cut some threaded rod, inserted into the sleeving, stuck into tank. Charger + to rod, - to tank mounting bolt, 10A scale. Connected an ammeter to read current. The rod instantly started fizzing

After first day, solution was really rusty. Couldn't really tell if it was working, but rusty water means less rust in tank, so I kept going. Every day I replaced the dirty solution and cleaned rod. Usually after a few hours the current went to .1 amps or less which means it's time to change the solution.

After about 5 days I could see spot of metal showing on the botom of the tank. After 10 days it was 50% bare, then after about 14 days (today), the rust and all that 1/2" of crap is TOTALLY GONE! It's really amazing. Plus, it actually plates metal on the tank instead of removing stuff. Really cool. Not going to need any coating I think. So anyways, I'm thrilled with the results and thought I'd share them.

Now I need to figure out how to install the oil pump so that it doesn't wobble on the shaft... it's a very tight fit for some reason.

Biz

Smithers · #2 01-20-2011, 06:33 PM

Wow good work! I would love to see some pictures of this action. I bought a small ultrasonic cleaning tank from Harbor Freight that works wonders. I can't put a fuel tank into it but a friend of mine has one at his work that I can! And I have a couple of tanks to try out with this method. I got a bunch of pictures I want to show here in a write up so I'll let you know when I get them online. Great to hear of a successful tank cleaning. This is a big issue for us restoration guys.

wwager · #3 02-08-2011, 05:12 AM

I am very interested in trying this on a rusty tank I inherited. Question is, why steel rod? wouldn't brass be better?? What is the chemical in arm and hammer washing soda - sodium bicarbonate?

Spokes · #4 02-08-2011, 03:51 PM

Arm and Hammer washing soda is sodium carbonate.

The anode and the cathode have to be the same metals.

wwager · #5 02-08-2011, 06:54 PM

Spokes,
Thanks for the information - I'll try your method. Any advice on finding a service manual?
Walt

Spokes · #6 02-08-2011, 07:41 PM

Somewhere I have the manual on a pdf file. I bought a new computer and the files are somewhere on a back up disk. You should be able to find a hard print manual on eBay. Maybe other members can help out with this.

I do have the parts pic and list on a pdf file. You have to pm me with an email address.

comp_wiz101 · #7 02-08-2011, 09:40 PM

I think you can get a copy from this thread: http://www.fourwheelforum.com/showthread.php?t=787
Otherwise, I can send you my copies of the C95 drivers manual, and the CA95 Parts and Service manuals.