Fuel Tank Cleaning

[mattsz]

Herein lies the problem for us newbies who need to de-rust a tank for the first time - so much conflicting info everywhere... 

[kevski]

Herein lies the problem for us newbies who need to de-rust a tank for the first time - so much conflicting info everywhere... 

No false info here, i am a former plater and metal chemist, the best way to do this at home is brick cleaner and a handful of pea shingle, seal tank, agitate, drain and rinse with loads of D.I water, the DI water is important, then dry quickly and swill with WD 40, i buy it in 5litre cans, no twatting around with aerosol cans, trying electrolysis is hit and miss at home due to lack of the correct equipment and knowledge.

[Rob62]

Electrolysis at home is a piece of piss as long as you adopt the correct method...there are hundreds of descriptions on the internet all describing the same technique..12v battery charger (everybody has one) connect positive to metal wire suspended in tank (metal coathanger will do), negative to tank as described. I used “arm and hammer” soda crystals to make the electrolyte as they are often recommended. It works very well. As with all forums, you have to do a certain amount of filtring. My suggestion of the electrolyte method is merely a suggestion, others will suggest other techniques i.e acids etc.... But the technique I described is correct, you dont need to be an “expert”, just connect it up the right way round.

[kevski]

Like i said incorrect equipment and lack of knowledge.

[mattsz]

I rest my case.  Kevski, to be clear, I said "conflicting"; I did not imply, or state outright, that any of your info is false.

I'm not saying that having all these different options is a bad thing.  Everyone obviously has their own ideas of what's best; it just makes it a challenge for someone like me to decide how to proceed.  No matter which method I choose, if the result isn't perfect, or nearly so, I'll second guess not only my execution of the process, but also my choice of processes...

[Rob62]

Well Matt, either kev’s right and everybody else who uses this technique is wrong and it doesn’t work....or its the other way round... you decide 

[kevski]

Well Matt, either kev’s right and everybody else who uses this technique is wrong and it doesn’t work....or its the other way round... you decide 

Its not about right or wrong, its  about correctly, i done this stuff for a living not as part of a hobby and that's where the difference lies, i offer suggestions based on what you might have kicking around in shed, i will also let you know the correct way it's done, but ultimately i don't have rusty tanks in any of my vehicles.

[kevski]

Wouldn't making the tank itself the sacrificial anode ultimately weaken the tank?

Only if you plate out too long or the tank is done in to start with also the rust is already weakening the tank, what you are doing is taking the crap away from the tank and depositing it on the cathode, in the industry you clean using hot solvent or caustic based solutions and then it's D.I rinsed, then pickled with a 5/10% sulphuric acid rinsed again with D.I then plate up, timings are crucial,this is just a brief look at the process, naturally with tanks after the final rinse you need to dry it out quick and put protective coatings inside.

[K2-K6]

I understand it as kevski states.

The steel tank that has rust is already compromised,  or beginning to be, dependant on how much rust.

From a metallurgy point of view,  steel sheet has been rolled to get it's thickness to required dimension for component pressing.  This makes it effectively close to forged and maintains a compression of the surface that is a little resistant to corrosion because of its physical structure. It's this property that fuel tanks have taken advantage of for years,  so they've never really been treated during production.

If you've left a piece of sheet that's been cut in damp conditions,  the cut edges will very quickly corrode and general surface take much longer.

Once you cut, grind,  corrode etc you loose this refined surface compression,  making it far more likely to flash corrode as you further prepare it.

[Rob62]

Exactly  jesus! the poor guy only wants to know how to clean his tank..... i give up ! 

[Nurse Julie]

Keep it simples.......pea shingle.

[K2-K6]

Thought Jesus was more of a fish, wine and bread type of chap  doubt if he studied metallurgy 

[Trigger]

I understand it as kevski states.

The steel tank that has rust is already compromised,  or beginning to be, dependant on how much rust.

From a metallurgy point of view,  steel sheet has been rolled to get it's thickness to required dimension for component pressing.  This makes it effectively close to forged and maintains a compression of the surface that is a little resistant to corrosion because of its physical structure. It's this property that fuel tanks have taken advantage of for years,  so they've never really been treated during production.

If you've left a piece of sheet that's been cut in damp conditions,  the cut edges will very quickly corrode and general surface take much longer.

Once you cut, grind,  corrode etc you loose this refined surface compression,  making it far more likely to flash corrode as you further prepare it.

I started to read that and my brain said "Sod this, I'm going on holiday"

Can i come 

[waffey]

My tank was rusty inside, I used DEOX-C to clean it before I liberally coated the inside with oil for storage. 

I had good results from (I don't have the pictures to hand). Not expensive, water soluble.

you can find it here https://www.bilthamber.com/corrosion-protection-and-rust-treatments/deox-c