Thoughts on preventing newly de-rusted tank from corrosion.

[AshimotoK0]

After the fantastic response to me asking about removing stubborn carb drain screws....

What's everyones favourite treatment for the inside of fuel tanks after de-rusting (assuming the tank is not going to be filled with fuel for a long time). Anyone know how Honda did this ? .. I just looked at the inside of a 52 year old NOS tank that was missing it's original tape over the filler hole but absolutely no signs of corrosion whatsoever. I am having this tank painted another colour and amazed how thin the original Honda paint is, with no obvious evidence of any form of primer, yet the paint finish is blemish free (original finish was  metallic not candy paint)

[florence]

many years ago I bought a new old stock cb350k tank from David Silvers stand at the NEC (1986) and it had a very thin film of oil inside.

[SteveW]

2 stroke oil?

[Nurse Julie]

Anything oil based... We store tanks full of diesel for long term storage or swill the diesel around the tank and empty if you prefer. It is the film of oil that gives the protection.

[Rob62]

A bit of 2 stroke premix sloshed about will do the job.... rinse out before use and shouldn’t cause any smoke. Just out of interest, i recently acquired a rd350ypvs which had a bit of rust inside the tank.... i have previously used electrolyte and a battery charger to de-rust tanks but its a bit of a faff although it works well. This time i decided to try some of that evaporust stuff that sounds too good to be true.. its £30 for 5 litres but can be reused..just pour it in and wait...its not acidic or caustic so doesn’t attack paint plastic or aluminium or the steel itself (acid does). All it does is break the chemical bond between iron and oxygen thus destroying the rust, it isn’t strong enough to break the bond between iron and carbon so doesn’t damage the steel either.... but best of all it actually works brilliantly! You can also derust any other ferrous object, old nuts and bolts, tools, brackets...anything. Just drop them into a container of the stuff for a few hours... then pour back into the bottle to be reused again... magic.

[AshimotoK0]

Yes I was thinking 2-stroke oil myself.

Will try the Evaporust stuff ... My Bomber tank is brimmed with Bilt-Hamber DeoX-C at the moment . Anyone got experience with that vs Evaporust ? We use Deox-C at work so I cadged some of that.

Lot of theories online is that DeOx-C is basically citric acid crystals and wetting agent ... the  fact that it is fit for human consumption kind of goes along with that.

[florence]

this is very good, I thought rusty tanks were beyond salvation.  I think I will try that stuff in my flail mower tank.

[adespin]

Yes I was thinking 2-stroke oil myself.

Will try the Evaporust stuff ... My Bomber tank is brimmed with Bilt-Hamber DeoX-C at the moment . Anyone got experience with that vs Evaporust ? We use Deox-C at work so I cadged some of that.

Lot of theories online is that DeOx-C is basically citric acid crystals and wetting agent ... the  fact that it is fit for human consumption kind of goes along with that.

I recently used Evaporust on my K1 tank (very rusty) and wasn't impressed, left it in for two days, still rusty inside, then used the electrolysis method, that made a big difference.

[AshimotoK0]

Anyone tried this POR15 stuff  ..  I got 5l of it at an autojuble for a tenner.. seller said it was good but not tried it in anger yet.

https://www.frost.co.uk/por15-prep-metal-ready-946ml/?gclid=CjwKCAiAy9jyBRA6EiwAeclQhHntiLwlf400IMcWhNeIB37eGb-XFlb5LmL81VpKvXjrnz1-qJV0qBoCxIMQAvD_BwE

[Lobo]

I remember Tom400f treating his tank with POR15... (the thread here), and seem to remember him being very pleased with the results.
www.sohc.co.uk/index.php/topic,4758.msg24310.html#msg24310

On another note, IF you were to store your tank with say, a 50:1 2 stroke mix, would there be any real issues just then riding it? Would you have to richen the mixture a wee bit to compensate the ‘displaced’ petrol? Bottom line, I ride the SS50 only occasionally, and would like to protect the tank better, whilst not turning things into a faff every time I use it. (eg emptying the tank / sloshing with diesel etc)

[mike the bike]

I always wonder why people risk putting tank lining goo in their tanks instead of filling the tank with a copper sulphate solution, putting some copper pipe in the filler, connecting it up to a battery and copper plating it. 

[kevski]

Oil in the tank drain off and dry storage, like in my spare room, in answer to Mikes suggestion about copper plating that's a no as it's not that easy and will peel off and block fuel line and carbs eventually, it needs to be copper struck or nickeled first for good adhesion with prior cleaning and pickling and then you need to plate at correct current densities, you would still have problems in the lower areas and along the seems as the throwing power is greatly reduced, oil coating is best.

[mike the bike]

Ok,  just wondered.

[matthewmosse]

Regards de rusting, I brewed up some cider that wasn't that successful a few years back, it's been sat stewing for years and actually made a really good cider vinegar,  only I dont have a use for 60 gallons of cider! Then last month I was given a large box of rusty engineers drills, I found a 24 hour soak in the cider vinegar got the drills remarkably clean, you could even read the engraved or etched information that was previously lost to rust quite clearly, most came up like new though a few had pitting and theres no reversing that sadly I was amazed at how well that free cleaner worked, and the resulting waste is organic and fine to tip on the compost heap, no disposal issues. I prevented further rust by applying tapping fluid over the top layer of drills in the box, its spread over everything quite well just being left to spread by itself, and I know its effective long term as none of my own drillbits are rusty even after 15 years in a damp shed. In a petrol tankI'd use 2 stoke oil or diesel, if any is left behind when recommissioning I reacon a bit of extra lube for the top end would be no bad thing.