Removing rust from inside steel tank

[FDR]

Old steel mx tank has patches of rust inside.
Any advice on how to remove.
Regards, FDR

[lc4]

Rust remover from Super Cheap Auto , pour in put cap on a give it a good shake. Keep a eye on the rust being removed and when happy flush out with a water hose. Dry out with heat gun or hair dryer and throw a bit of two stroke oil in a give it a good shake.

[Slakewell]

If you have one an old cam chain when shakeing inside the tank

[FDR]

Thanks Slakewell, will give it a try.

[retrowrex]

Have heard that some ball bearings or something like that is the go as well.  Don't know for sure.  All my bikes have plastic tanks.  With no rust inside them.

Retro

[FDR]

Cheap option, pebbles from a mates driveway, will mix with rust remover and shake.

[VMX247]

Have heard that some ball bearings or something like that is the go as well.

also If you have a cement mixer and a few blankets and block it firmly in the mixer you could give it a few rolls to clean it out ,needs to be done a few times..Have seen this illustrated in a bike mag.Don't sue me if it crash and burns though.  
bit more info in the below.
http://ozvmx.com/community/index.php?topic=144.0
cheers

[jimson]

phosphoric acid glooves googles once you do it it leaves a cover over the metal and slows the rust return don't get it on your paint work. jimson

[oldfart]

Try this.    works for me                     Molasses  first - and then rinse with Phospheric acid.
http://virtualindian.org/projrust.htm

[ji107]

Try to get hold of a product called 'Corrodip'. I get it in SA from a yachting chandlery. About $35 for a litre, water based.Mix with 4 litres of water, pour into tank and leave o/nite. Where the liquid wes in contact with the steel, like new. Will have to turn it around a few times to get all surfaces.
Liquid can be kept indefinately in a plastic container

[DT_Mania]

I know that there is also a product where they put a thin plastic film inside of the tank. They blow it in with pressure like a balloon. That gives you relieve from the rust messing with your carbie.

[shorelinemc]

get a POR 15 kit removes rust,preps the surface and then coating works great and will fill small holes

[211kawasaki]

Molasas
10% with water; check every day
will be good as new in a few days - and taste good to
get from local horse shop

[pbear62]

Be careful if you're going to put ball brgs, nuts & bolts inside - too much vigorous shaking can cause tiny dents from the inside! I've heard of people using white vinegar to dissolve the rust too. After treating the rust, some people line the tank with Kreen or POR sealer - main problem with these is that if ever you need to weld/heat the tank later, they give off toxic fumes & the sealer gets stuffed by the heat.

[LWC82PE]

I use this hydrochloric acid and wouldnt waste my thime with anything else. It works fast and works well.

know that there is also a product where they put a thin plastic film inside of the tank. They blow it in with pressure like a balloon. That gives you relieve from the rust messing with your carbie.

That is exactly the reason why liners fail, if you dont get all the rust out first before pouring in the liner. No point putting a liner in to cover up and hide the rust.