Ideas for a rusty tank
 

I've got a couple of gas tanks, all of which have varying degrees of surface rust inside.

Any (good) ideas to deal with it? I've heard of putting some small metal objects (nuts, etc) inside and agitating to clean the rust off, but then what?


Hard to get a tank to last 60 years these days without showing signs of wear
:bigthink:

There are baffles inside the tank that will not allow abrasives items to get to that area.

Best to research chemical de-rusting solutions such as muratic acid.
Just be sure to follow label directions as well as precautions.

Worked for me on my tanks.
Did several at a time so I could reuse the solution.

I'm going to ASSUME you are working on small engines not a motor vehicle tank.
If so, they have no Baffles, so throw in a handful of rocks, nuts or what have you and shake the shit out of it.
It helps if you put some vinegar in them a day or two earlier.
as it loosens/dissolves some of the light rust.
Depending what you have for contamination, other products might prove better if you have say varnish or similar.
Do take out any screen that might be in the outlet and put in a plug so the liquid will stay inside during the agitation process.
When finished, wash out with soap/ water and dry in the sun.
Rust in a tank that doesn't flake off, poses no problem, as it hurts nothing. :beerchug:

Thank you gentlemen.



Yes, sorry this is in a couple of Kohler tanks that I'm going to do, so baffle-less. I ordered some tank coat elixir and will use that after some mech/chem rust removal.

Darned alcohol/water in gas these days ...grrhhhh.



I appreciate the advice!

I have had pretty good luck using straight vinegar or maybe some Acetone.
Let it sit for a couple days shaking it up whenever I think about it.
Lots of soap and water after that.

Ken

Look up Evapo-rust. I never used it on a gas tank, but I have used it on other things and it works good. It is non toxic, and reusable. I was planning on using it on the tank for my 149, but then I found a nice rust free one.

Do as you like, I have no respect for a "cream" of sorts in a tank.
Maybe because I'm the one that is handed a mess that someone did a while back and it went all bad and am asked to "fixit up" because it rusted between the "coating" and tank or the coating is rattling around inside loose, like a pocket full of marbles.
No offence, just my experience.
Or like JB weld to stop a leak around a fitting.
Just fix it right by sweat soldering the hole or bung in the first place.
Luck!

What size tanks are we talking about here?
I can assure you that the larger ones DO have baffles in them
Take a pen light and look, towards BOTH ends.
Hell, you can even feel them if your fiddle finger is long enough.
I just checked several on my shelf that I cleaned last year and they ALL have them.
That's one of the first things I look for, rust in the tank.
Every Cub tank I have ever looked into has them.

Where is the adventure and wonder in that!?? :biggrin2:

Hi George,


I'm not trying to "fixit up", but to do it right. I plan to remove as much of the rust as I can mechanically/chemically/electrically , but given that I live in North Carolina, if I am successful at removing the rust that's there without some sort of coating immediately following it's going to rust again right away.

I *could * get by "fixit up" by just letting it continue to rust and depend on sediment filters and screens to get rid of the continual rust, but I hoped to do better than that, not to take the slack route. You're saying I shouldn't worry about rust in the tank after I knock the big chunks off mechanically?


This is a tank for a 123/K301



John

You can always take a torch to the seams of the tank and take it apart, then clean it up and have a radiator shop re seal them together again.

Get it clean then slosh some light weight oil around inside.
The ones I did a year ago still look like new inside and they have been empty the whole time on the shelf

Thanks...that's a good idea. In use the gas might strip the oil off which is what I was thinking of. I'll give it a go though!

Hi, I just saw your comment and since you're new, I'm not sure I understand it.

Are you saying that shaking the empty tank will rocks or nuts inside and calling it good is better than mechanically / chemically / electrically removing the rust and trying to replace the damaged tin plating with another material?



Just trying to understand the comment.

^^^ I was poking ole-George.

I have used clean pea gravel, rolled and shaken, in tanks to clean them. With a small tank, you could just strap it to a rear tire and drive around for a while. Think of a rock tumbler. No liquid, use that as the rinse.

I got it! That's a good idea. Actually I think I have a jar of tumbling media that's shaped like little triangles, though the pea gravel is probably easier to find. I an strap it to a wheel of my O and let it tumbled around on jack stands.



I tumble a lot of brass for ammunition reloading, so I know how well this can work. I'm always a bit leary of getting near a used gas tank with a torch. Lou you're braver than I am (and clearly a better sweat solderer!)


Meanwhile, as I have the engine out of this 123, I discovered a brazed crack in the frame. The brazing is cracked too. While I'm anything but a good welder, I'll get the grinder out and try and get rid of the brass, groove the crack a bit and see if I can wire weld top and bottom.

It's about this part of the process I have to remind myself what it is I set out to fix :-)


Oh, and the driveshaft pin hole is egged out. I'll split the tractor and see what the front of the hydro shaft looks like....


I suppose after 55 yrs things DO wear out....

AGAIN: What size tanks are we talking here?

Been my experience where ever there has been braze, it gets into the "pores" of the metal and trying to weld it produces Spatter/porosity like the metal is very dirty,
And I have wound up with a mess, even if ground away, I can't get it all out.
As far as parting a tank at the seems:
some are spot welded, some are seam welded/rolled résistance welded.
Few are just furnace soldered or furnace brazed.
Just my experience.
Myself, I clean up the loose scale and put the tank in use.
If storing a cleaned tank, do as others said, oil it inside.
Fuel in a tank has vapors which precludes moisture laden air, so rust mostly does not occur.
:bigthink:

Dont use an arc welder for two reason my friend said...
1 gas fumes
2 thin metal makes a small hole real big real fast.
(Thats when it goes to George to fix!)
Agree sweat solder is the way to go.
Also jb weld and gas usually doesnt do well.

I can honestly say I have never seen nor heard of anyone that tried to repair a gas tank with an arc welder.
But then again I'm sure that there is someone who tried. Here's yer sign!

* Thought I mentioned it, but it's a stock gas tank for a K301 in a Cub 123. I'm not sure of the actual dimensions if that's what's needed.


* There's NO way I'm going to try to take the tank apart...I know SOME of my limitations and I'll end up with a bigger mess than I have now. :-)



* My reference to brazing and wire welding were in reference to the frame crack (near the motor mount bolts) not the tank. I'm not taking anything with a flame or sparks near the fuel tank. :-)


* George, that's good to know about the weld. I've got nothing to lose as the brazer that went before me just puddled up brass over a crack and didn't laminate it with anything to provide strength . I'll try and remove as much as I can with a flap disk and do the best I can with the wire welder. It's under the motor, so it'll probably never be seen again.



I got everything in the manual disconnected in preparation to splitting the tractor so I can take a look at the other end of the driveshaft/fix the brakes, but it's not coming apart easily. I'll work again tomorrow.



My wife just commented that Sunday I mentioned "all I'm going to do is swap the motor out. How hard can this be?"



Famous last words!

BTW: It's the 123 in my avatar.

It's not going to be me, that's for sure!

:beerchug:

I have sealed 3 tanks over the years with Kreem. They are all still in service without problems. This is one;

https://www.onlycubcadets.net/forum/...593#post455593

My advice is to be prepared to continue the etching process for an extended period of time till you're certain that all rust is removed, even increasing the concentration of the etching solution if needed. Also, you must make certain that no puddles of sealant are allowed to collect in the tank. Puddles will never dry and will cause failures. Continue to rotate the tank far beyond the recommended times to make sure all sealant is completely cured.

Thank you. That's a really good description of the process, and hopefully my tank is not that far gone that its got pinholes .

I appreciate the link.

This is North Carolina. Steel rusts quickly!

You mean tank you!

:biggrin2:https://4.bp.blogspot.com/-P2l_vEoLt...0/rim-shot.jpg

(Insert appropriate amount of groaning here):bash2:

Seriously, though, this has been really helpful to read up on. Just because a tank leaks a little doesn't mean it's done for, like I always thought.
Wonder how many of the little engines sitting out back of the shed can be saved now....

Back in either '97 or '98, I sealed a Farmall Gas tank using a sealer product I got from an advertiser in Red Power Magazine. I had never done this to a tank before, so I followed the instructions very closely. I cleaned and prepped it as thoroughly as I could. I spent a lot of time on it. The tank had baffles and a few pinholes in it, but I went ahead because I wanted to save the tank.

It was a success because it is still good to this day (probably jinxed myself now :angry:).

It was this stuff:
https://www.theshopproducts.com/prod...nk-sealer.html

Never used it before or since, so the only experience I have with it is that one tank.

While I generally hate plastic stuff, it's too bad there's not a "bolt in replacement" for the CC tanks made of the same heavy plastic that gas portable gas cans are made of. The tricky think about that arrangement would be sealing the gas feed port, but it can be done. The 782D I have doesn't seem to drop diesel from that grommet arrangement in the bottom of the plastic tank.

Kohler does make em' and ccs has a picture of one.

Yup.....they're out there!

I can see why they're still out there! He's clearly of the "this way all I have to do is sell one" theory of marketing.


( that's an insane price ).



:biggrin2: