Calling all metallurgists

[dbeardslee]

After having my tank coated, and subsequently developing a gas leak, I was thinking about trying something a little different. I read another post about an individual that was trying to use electrolysis to de-rust the inside of a tank. Evidently he had his wires crossed and disolved four or five coat hangers.

So here's what I'm thinkin'. If I take a tank, and de-rust the inside using electrolysis, then reverse the polarity and swap a pure tin bar for the coat hanger anode, it should tin plate the inside of the tank, right?

Any thoughts?

[xs11jack]

Yes.

You can use reverse electrolysis if the donor metal is a bit softer than the recipient metal. The problem with tin is that it is hellishly expensive. You undoubtedly have heard the term "tin can." Cans, especially those containing food, were coated with tin to stop the cans from corroding on the inside. But now the cans are coated with plastic, even so, a badly creased modern can can have the lining compromised and the food go bad. If you do want to try this, do a ton of research first and then go after your tank.

[dbeardslee]

I found a place that sells one pound bars for $14. I don't know how many it would take, but I wouldn't think it would be more than two or three. The tank that sprang a leak I had professionally coated by a local radiator shop to the tune of $125. I did another one myself with the stuff from caswell plating that didn't turn out so great, although it's good material. It's just so difficult to get the liquid stuff to flow evenly all over the inside of the tank. I'm thinkin' that plating it would build up the overall thickness of the metal, as well as providing corrosion resistance, and should provide more even distribution of material. Your right, though, I gotta do some more homework.

[mro]

Wonder what would happen if you used a couple rolls of nickels?

(our nickels are copper/nickel alloy)


mro

[dbeardslee]

That would be cheaper. I think I'm going to setup a little test bucket and experiment. I kind of like the idea of a nickel-plated gas tank. I wonder if I submersed the whole thing if I could do the outside too

[mro]

Take pics!!!


mro

[red bandit]

I kind of like the idea of a nickel-plated gas tank. I wonder if I submersed the whole thing if I could do the outside too

That would be WAY COOL!!

[xschop]

Tinning

Why don't you tin braze the large hole first and then nickel plate it, just nickel plating will not seal even small holes because it will only lay on a few microns.

[dbeardslee]

The hole is in a different tank. Unfortunately it's been coated, and I found the hole after I repainted it - you know, the hard way. On that one I tried a different experiment. Had a plugged drain tube that I drilled and cut out and replaced with a piece of 1/4" copper tubing. I cemented it in with JB Weld which has worked well so far. I missed a little pinhole in the tunnel, and that's the one that leaked.

Luckily it's back where you can't see it when the tank is mounted. I just need to sand it, JB it, spot prime and repaint with a brush. Can't put heat on it with that coating inside. I'm going to get another tank ready over the winter, just in case my repairs don't hold. It may wind up hanging on the wall for a while, which is one of the reasons why I want the inside coated with something that won't rust.

If I did go the full monty and did the outside it would definately be a night-time only tank. I hate those under the chin sunburns

[xschop]

sealer

I used some fuel tank sealer on my XJ tank right at the back where there is.....WAS a factory tab to hold the fuel gauge wires, it was broke off and had a pinhole that bubbled up the new Blue-Streak paint. I just shot some Aircraft paint stripper, removed paint and scrubed the area real good with a small stainless steel brush. Then I mixed the 2-part putty together and molded it to the hole area.... it has held for a couple years now.

[gareth]

I vaguely remember something about a company that "tinned" cookware locally. I'm not sure if this service was confined to copper saucepans etc, but the idea was that the items were cleaned, a flux was applied and molten tin was floated around the pan until it was fully coated. I suppose that something similar could be done with a fuel tank. The coating would certainly be much thicker than could be achieved with electroplating...
Obviously this would be a very specialized operation for something as large as a fuel-tank, but while we are talking about alternatives to the normal acid cleanout and seal... I figured I would mention it.
Not recommended btw for older tanks that were soft-soldered together...

[Geezer]

It's impossible to get an even coat of electroplating on the inside of the tank. You would need multiple anode strips and even then you couldn't guaranty to get all the spots you wanted covered.

You can get tin in a wire roll at home depot in the form of safety solder. The stuff is all tin.

There's a place here in Portland that retins copper cookware. It seems the fancy copper pans used by chefs have to be recoated from time to time. They have a tank of molten tin they dip stuff in. One of the local by restorers turned me on to them. Apparently you tank a tank that is rusted to the point of having pin holes, have it dipped and it will be better than new. For about 150 bucks.

It's never been worth it to me.

This link might be helpful.

http://www.ehow.com/how_2180910_washing-soda-electrolytic-rust-removal.html

Geezer

[mitch]

Tanks for the memories

I used to repair gas tanks for a living. Electric iron(industrial) Clean the area then tin it ( cover the area with solder ) cut a tin patch to match , tin the patch then sweat it down to the area. Then run a thin coat of solder around the edge. Plug all holes and submerse under water look for air bubbles. Body fill and paint Liguid flux works best for this and clean its gotta be clean!!
Doug

[The Lorax]

I used to electro plate....15 or 18 years ago. You will need some kind of acid for the process, I think fluoboric for tin, boric and sulfuric for nickle. also a good power supply that can deliver somewhere around 15 amps per square foot of material you are plating to. and if I remember correctly, some kind of organic brightner so that the metal being plated adheres to the tank evenly (I think molasses will work for some metals...copper and maybe nickle ), otherwise, it "burns" and basically the plated material gets deposited to the tank in clumps and doesn't stick well at all. make sure that the tank is well cleaned (chemically) and all should work out just fine. go to your local University library, you can get recipies for virtually any type of plating bath you want. Copper, nickle, tin, lead, solder (yes, and the current density will determine the alloy), even gold (avoid gold, you have to plate nickle on first, and gold plating requires the use of potassium cyanide, don't get acid in the gold bath, cyanide gas, you know). That is about all I can remember about the electro-deposition of metals. hope it is of some use. have a nice day and ride safe.

[dbeardslee]

I bought a tank on e-bay (tank, two badges, two vacuum petcocks, fuel meter, fuel door and trim ring for $49 delivered ) that arrived wednesday, and I immediately went to work on it. I had been looking for Arm & Hammer Washing Soda and was unable to find it in local stores. I did a little more digging and found out that sodium carbonate is a chemical commonly used to regulate PH in swimming pools. Found it in a local hardware store. They also call it soda ash. Anyway, I got the chemical and a 1 11/16 inch rubber stopper (fits perfect in the filler neck), drilled a couple holes through it and put a bent coat hanger through it.

What a magical process. I couldn't believe the crud that came out of the tank. I also had a plugged drain pipe, so with the tank completely filled with solution and the plug in place, I added more solution around the outside of the filler neck so that it made contact with the top part of the coat hanger. It removed the rust around the fuel door recess, and also broke it loose down in the drain pipe, so it works now.

After The Lorax's post, I did a little checking on chemical baths. GEEEOOOD is that stuff expensive. Caswell Plating sells the chemicals in kit form, but I could buy a bunch of tanks for what they cost. They also sell a gas tank sealing kit for $32.52 that has enough material to do 2 5-gallon tanks. I've used it before, and it's good stuff, but it sets-up hard as a rock. I screwed up on the last one by letting it cure, and then tapping the screw holes. Should have pre-drilled the holes 'cause I broke a tap off in one of the holes for the fuel meter and in my attempts to extract it managed to break a weld on the flange. Scrapped the tank. Hopefully I won't make the same mistake again.