Series 2 survivor

[dickie]

Just thinking about storkfoot's recent rusty tank problems. I just wiped my finger in the top of the tank. Not good.

Not sure what to do about this, but I'm not just leaving it. Maybe try white vinegar like nobby did in his very entertaining video?

[dickie]

This is a brand new fuel tap that I just installed. You'll notice I swapped the insert for a metal one and used the original nut.

But the main thing is the rust!


Also, look at this!


No, this isn't my y fronts after a night of lager and curry. It's a white tee shirt that I filtered the fuel out of the tank through.

[Storkfoot]

From my experience, definitely don’t leave that. I cleaned the whole tank again but upside down to make sure the area at the top of the tank was cleaned. First caustic soda for a couple of days, then spirit of salts and finished off with a rinsing of rust remover.

[dickie]

while I'm sure that Nobby's white vinegar or Storkfoot's chemical process are perfectly good techniques for tank rust removal, I have chosen to try electrolysis, partly because I suspect it will be more thorough, but mostly just because I think it's an interesting thing to try.

First I cleaned out the tank with hot soapy water, as oil is a good insulator, so may affect the process.

Then Mixed a solution with about 100g of bicarbonate of soda and hot water, making sure that all crystals were dissolved before pouring into the tank.


I made an anode by drilling a piece of plastic and fixing some stainless m6 studding into it, as long as possible WITHOUT touching the bottom of the tank.

The tank was full to the brim to make sure I cleaned the top surface.
The tank is the cathode.
So I connected the red, positive lead of my power supply to the anode, and the black negative to the cathode.


I set the power supply up to only deliver 500mA, just out of a slightly cautious nature, but i think I'll wind it up to 2A, just to hurry the process along.


Here you can just make out the bubbles. these are hydrogen so you need to do this is in a well ventilated area to avoid blowing shit up.


Let's see how it works out?

[dickie]

I just whacked it up to about 3A and it's bubbling away much faster now.

[Warkton Tornado No.1]

Hey Dickie.

Thank you for outlining how any of us could go about using the process of electrolysis to remove rust. I suppose the main issue for most of us would be the provision of a stable electrical supply....

However, the anode material choice surprised me. I don't know why I anticipated it would be copper. That said, there are several types of stainless: austenitic etc. Is the grade important?

[dickie]

Mark, to be honest, I'm not an expert in this, I just followed someone else's advice. As normal, I checked a few other sources before I believed it (too much BS on Google).

This seemed to be the best set out advice, so I just went along with it. I particularly like that there is a "tool preservation society "

https://htpaa.org.au/resources/rust-removal#:~:text=The%20electrolytic%20method%20involves%20immersing,electrode%20dipping%20into%20the%20solution.

The stainless I used was A4, approximately the same as 316 so austenitic. I used because I had it, no other reason.

I'm also half-considering trying to zinc plate the inside of the tank, but there is wildly conflicting advice about the wisdom or otherwise of doing this.

Yes, I realise not many people have access to a power supply like that, but they're relatively cheap; £30ish quid I think. But an old type battery charger would work just as well, as long as it''s able to deliver 1 or 2 amps, it'll work fine. The stability of the current isn't that important actually, it just means when the current is higher, it's working faster.

[dickie]

So I left the tank under electrolysis for about 24 hours. I emptied the bicarbonate solution out and it was orange. Not a deep orange, but orange. I had bought some 40% white vinegar, which I emptied into the tank and had to add about 3litres of water for a full tank coverage, making it about 25%. Again, I left overnight then emptied and flushed with water. I was still not convinced so I sloshed premix around and filtered through an old white tee shirt about a dozen times before I was convinced that it was clean. Some job, but I'm happy now. I wish I'd done the sloshing and filtering outside as I ended up with a thumping headache.

[dickie]

Next on the list of jobs was to check my junction box which is actually an old rectifier housing with the rectifier removed and a capacitor added to stabilise the DC voltage.

A mate had a tv200 built by someone who coincidentally used the same rectifier housing but purely as a junction box. The first time my mate rode it, he smelt burning after just a minute or two of pottering about his estate; the burning was at the junction box. I investigated for him and found it was high resistance between 2 terminals.

Anyway as a precaution, I checked mine.
This should be about 0.5ohms, which is just my meter leads resistance.


So I drilled the rivets out

And added a blob of solder after cleaning up the brass pads


Jobs a good un.

I need some m3x25 screws to put the box back together, but that's nowt.