Fuel Tank Clean with Electroylysis? - PeachParts Mercedes-Benz Forum

warmblood58 · #1 03-07-2013, 09:36 PM

My w115 300d has a rusty tank from sitting for several years with little fuel in it. Thinking about pulling it and using the electrolysis technique with a battery charger, anode and a soda water solution - did this on seat springs and it worked great! Has anyone done this? I will recoat tank on the inside and was wondering if anyone has used a product that they could recommend to reseal inside of tank to eliminate problems in the future - Any thoughts? Thanks!

vstech · #2 03-07-2013, 10:30 PM

IDK, usually, electrolysis removes the rust and leaves less metal than before... I don't think I'd try it on a thin fuel tank.
coatings usually don't stand up to diesel or daily use anyway...
I'd just put in some tank cleaner, flush it out, and use it with diesel in there and monitor the clear filter for flakes...

warmblood58 · #3 03-08-2013, 10:56 AM

Quote:

Originally Posted by vstech

IDK, usually, electrolysis removes the rust and leaves less metal than before... I don't think I'd try it on a thin fuel tank.
coatings usually don't stand up to diesel or daily use anyway...
I'd just put in some tank cleaner, flush it out, and use it with diesel in there and monitor the clear filter for flakes...

Take it to a radiator shop to boil out or is there a cleaner you can recommend? Thanks! Hate seeing evidence of rust inside IP as was just noted by my indie -

whunter · #4 03-08-2013, 11:24 AM

Many of the VMCCA and horseless carriage members have taken fuel tanks to this company Gas Tank RENU - USA with good results.

.

warmblood58 · #5 03-08-2013, 11:28 PM

Quote:

Originally Posted by whunter

Many of the VMCCA and horseless carriage members have taken fuel tanks to this company Gas Tank RENU - USA with good results.

.

Thanks Hunter - anyone know if its true that most tank sealers are not compatible with diesel

whunter · #6 03-09-2013, 01:58 AM

Quote:

Originally Posted by warmblood58

Thanks Hunter - anyone know if its true that most tank sealers are not compatible with diesel

That is a loaded question, begging the argument.

Only the product manufacturer can actually answer your question, due to variables:
* Cleanliness - preparation.
* What materials - coatings it will bond to.
* Chemical compatibility with diesel.
* Formula changes and other issues only they would know about.

I use off the shelf products for junk vehicles = Band-aid before it is salvage.
Take the tank to a professional, IMO it is worth the money for them to deal with the mess.

.

Chris W. · #7 03-09-2013, 07:31 AM

Although I have not done an electrolytic clean on anything, it's my understanding that you sort of need a "line of sight" from the anode (cathode?) to the work piece. I don't think that unless you set up something fairly elaborate to hold the electrode inside the tank that you would get a good effect inside the tank.

You would also need a BIG vat to put the whole tank in! Assuming you want to derust both the inside and the outside, that is.

Rgds,
Chris W.
'95 E300D, 389K

warmblood58 · #8 03-09-2013, 01:35 PM

Quote:

Originally Posted by Chris W.

Although I have not done an electrolytic clean on anything, it's my understanding that you sort of need a "line of sight" from the anode (cathode?) to the work piece. I don't think that unless you set up something fairly elaborate to hold the electrode inside the tank that you would get a good effect inside the tank.

You would also need a BIG vat to put the whole tank in! Assuming you want to derust both the inside and the outside, that is.

Rgds,
Chris W.
'95 E300D, 389K

Easy, fill, tank with soda solution, put rubber stopper in fuel inlet with center hole and long curved rebar piece through center of rubber stopper and attach charger to tank and anode - I am just removing rust inside tank so total submersion as I did with seat springs not necessary. Starting to think about doing this again . .

Stretch · #9 03-09-2013, 01:55 PM

Eastwoods do a fuel tank rust stopping and sealing kit - as does POR-15 and KBS...

BillGrissom · #10 03-09-2013, 04:32 PM

One of the TV shows just covered this today (one with Tennessee boys, Horsepower TV?). They had a cut-away motorcycle tank showing before and after treatment. I forgot the product, but I recall one of the 1 gal phosphorous "rust treaters" that usually convert the rust chemically, but it looked light grey instead of black. You can find at Ace Hardware or auto parts stores.

97 SL320 · #11 03-09-2013, 06:21 PM

Electric rust removal causes hydrogen embrittlement and should not be used on stressed parts without baking out the part immediately after removing rust. This isn't an issue for a fuel tank, but is a problem with springs, torsion bars and other shafts.

Supposedly, if a stainless electrode is used it can make toxic gas / solution.

How rusty is the tank? Can out put a scotch brite pad on a stick and scrub the rust?

In extreme cases ( on construction equipment ) I just cut a hole in the tank top for access, scrape clean and weld back on. Sometimes it isn't worth trying to clean and I cut the entire bottom of the tank out then weld in fresh.

If you are just removing sludge, denatured alcohol works wonders.

warmblood58 · #12 03-09-2013, 10:53 PM

Great alternatives here, thank you!

Silber Adler · #13 03-10-2013, 08:21 AM

I have used KBS systems tank sealer system on several motorcycle tanks over the last 8 years. I have not had a failure yet.

It is a 3 step process that uses a detergent cleaner then a zinc phosphate containing solution to dissolve the rust. The coating is a single part solution that goes in thick. You have to keep the tank rotating around for a certain time. It cures in the presence of moisture, remains flexible and doesn't crack. I am enthusiastic about it.

Discussing tank sealer systems are a bit like tires or oil. Many have a favorite

I am not sure if it was discussed but perhaps finding an alternative tank is a good option.

That is one thing I prefer about my Mark 2 VW, The tank and neck are molded out of one piece of plastic. No rust.

funola · #14 03-10-2013, 12:43 PM

Quote:

Originally Posted by warmblood58

My w115 300d has a rusty tank from sitting for several years with little fuel in it. Thinking about pulling it and using the electrolysis technique with a battery charger, anode and a soda water solution - did this on seat springs and it worked great! Has anyone done this? I will recoat tank on the inside and was wondering if anyone has used a product that they could recommend to reseal inside of tank to eliminate problems in the future - Any thoughts? Thanks!

Are W115 tanks constructed differently than 617 300D tanks? 617 300D tanks are coated with a lead/ tin compound that is very resistant to rust. I have a 617 tank sitting outside for a few years now with no fuel in it and I don't think there is any rust inside. I will take a look.

Where exactly is the rust on yours and how much?

whunter · #15 03-10-2013, 02:11 PM

Quote:

Originally Posted by funola

Are W115 tanks constructed differently than 617 300D tanks? 617 300D tanks are coated with a lead/ tin compound that is very resistant to rust. I have a 617 tank sitting outside for a few years now with no fuel in it and I don't think there is any rust inside. I will take a look.

Where exactly is the rust on yours and how much?

The W115 fuel tank mounts under the entire trunk floor.
*
*

.