Im in need of doing mine. Have been suggested to use distilled vinegar or cider vinegar also ball bearings inside and given a good shake. Should loosen off all the rust then something like POR 15 (I think its called) to line the tank to protect it from more rust.
In terms of cost to effectiveness there is nothing better than electrolysis. http://www.parduebrothers.com/minibike/electrolyticderustingfueltank.pdf Vinegar does work, but takes bloody ages, something like phosphoric acid is better. POR-15 Is great, but isn't the cheapest, but it does include a tank sealant so It wont rust again.
I've generally heard that ball bearings and a liquid work - have heard of people using white spirit and all sorts of other stuff. 2 pack tank sealant is a good idea but it does need to go onto a properly prepared inner or you will just trap rust between the metal and the sealant layer.
Ball bearings & Stones etc work well, But you can dent the tank if you apply too much pressure. 2 Pack Sealer is the way to go If you want to spend money !
I'd do this way with the chain. Seen it done on a video and it came out caked in all the rust and shit. Only thing I'd recommend after his is maybe pouring some resin into the tank and moving it around for a while, so the resin can coat all of the inside and prevent it from rusting up again? I'm no expert though. Sounds like a good idea to me.
I did the same method on an old Moped frame project I had a few months ago, This is now ready for the rust removal Process. I only had one container suitable for the process, The paper wheelie bin that rarely gets used ! The bike is suspended slightly, with two pieces of Rebar acting as Anodes. After setting it up properly, and turning the power on i was greeted with this after around ten minutes of being on. Excuse the writing, I copied this from another forum I post on ! The process is exactly the same, It's just you would be using the tank as the container rather than submerging all the tank, otherwise It would need to be re painted. I've used electrolysis on all sorts of things from tools to that above ^ It works brilliantly.
Just to clear up any confusion (If there is any!) Lilday meant the method at the top which uses a household chain, Not the chain which spins the wheel on a bike!.
^ I posted a link above which explains how to do it. http://www.parduebrothers.com/minibike/electrolyticderustingfueltank.pdf For the chain you get a length of regular chain (Not galvanized) Something like this should do http://www.toolstation.com/shop/Saf...eel+Chain+3mm+x+21mm+x+25m/d200/sd2612/p43733 Then when it's in the tank to insulate it against the metal sides, but to allow current to pass through you put the chain in a piece of hose pipe/rubber pipe with large holes drilled in the side. There is another tutorial here http://www.instructables.com/id/Electrolysis-rust-removal-motorbike-fuel-tank/?ALLSTEPS Where the person doesn't use a chain, and uses a steel bar which is insulated at one end, The end results should be the same, but you would have to take the electrode out and wipe the crud off it more times. The idea is to fill the tank with water, and a baking soda mix (From asda, or somewhere like The Range) two or three teaspoons in the tank should do. Your anode is then placed inside the tank (The chain or metal bar connected to Positive power) And the cathode is connected to a location suitable on the tank (This is to ground the tank) You then apply something like 12 Volts from a battery charger & battery, or a decent power supply and leave for a few hours. When you get back remove the anode and clean all the rust off of it. You would have to repeat this every few hours (Just wiping the anode) until maybe it has been on for a full 24 hours. Once the tank is free of rust you just have to check there are no flaking rust spots left, and clean the tank out with a hose/jetwasher. Then you can leave it as is (It will most likely rust again soon if left untouched) You can just pour a bit of oil in and slosh it around and drain the excess to give a bit of protection, or you can use a proper tank sealer and seal the tank so It should never rust again.
Couple of bottles of bleach, couple of bottles of DIET coke (aspartame) and some clean gravel. Chuck it all in the tank and leave to soak for a few days.... shaking occasionally.
Electrolisys gets my vote, have done two tanks this way and happy with them ,but be aware the tank has to be in reasonable condition and not nearly corroded through
So if I understand that right, if you can get a zinc or high zinc content chain, the zinc should be deposited / fixed onto the tank so it gets galvanised anyway to reduce future rust potential even if you don't use a lining solution? I might have a trial on a small rusty tin or something before I attack a proper old bike tank.
No, You have to use a completely standard steel chain, It transfers the iron oxide from the rusty tank to the chain, But doesn't do anything to prevent rust afterwards.
I did mine in work the other night, put cider vinegar and distilled vinegar (cheap from asda) in with some nuts and bolts and gave it about 30 mins of shaking it about and rotating it. Its got all the loose rust spots off but it still looks rusty inside. I have just put some old oil from work in for now and given it a good swill round to coat the insides a bit, will see what its like when im closer to needing it back on the bike then if it needs any more will try the electrolysis
