Vinegar to clean rusted tanks?

[TonyBaxter]

I would second the comment on citric acid. Don't buy it from high street shops, even Wilko, get it from the 'net, several sellers on Ebay. A ruddy great tub of it, (sold for use in cooking) will cost very little and it goes a long way. Also, whilst you have to exercise care using it, it isn't as dangerous as some chemicals. If you DO like playing dangerous, then caustic soda is the way to go, though never near paint you're not trying to remove!

[MikeHenstock]

Many thanks. Sure I can figure this out but how do you block the peacock hole?

[JohnnyBeckett]

hi wen i did my tank i used my old petrol tap and that gave the tap a good clean as well and i used a pipe on the outlet of tap and blank the end of the pipe so you can have the tap open so it all gets cleaned in side tap, and now i have found a 3/8 bsp blanking plug, you will get one at most pluming shops its a standard pipe fitting, if you can only get a tapered plug use a bit of pluming ( PTFE ) tape on the plug and do not tighten it up to tight it can crack the fitting in the tank, then i use a old petrol tap or blanking plug wen i am doing the coating and sealing of the inside the tank

[MikeHenstock]

Brilliant, many thanks!

[alan.moore]

Mike
I use Oxalic acid (search google for Oxalic acid petrol tank forum ). It comes in crystals and is mixed 1:10 with hot water (100g to 1 lite water)

A point to bear in mind is that, whatever acid you use, its a good idea to nutralise it after its done its work. You can use bicarbonate of soda solution and then rinse well with water.

You will find that, having removed the rust and rinsed out the tank, the cleaned surface may well flash rust pretty quickly...especially if you use hot water to rinse it out. Methylated spirits will mix with any left over water, swill it round and pour it out.

Finally if you are not going to line the tank you can swill a small amount of petrol, with some engine oil mixed, in around the tank which should keep the surface rust at bay if you keep the tank sealed.

Whenever you remove rust from inside a tank you always run the risk of producing a pin hole, more so if the tank was pretty corroded. They normally appear in the area of the bottom seams. Using a fairly weak slow acting acid is therefore a good idea i.e nothing containing hydrochloric or sulphuric acid.

Cheers
Alan

[MikeHenstock]

Alan, many thanks. I'll go with oxalic acid so see how it goes

[pappleton]

Not Ariel related, but oxalic acid is ideal for removing black water stains from oak furniture. Just remember to neutralise it once the ring has disappeared - or you will have a white ring instead! It's pretty good for bleaching oak. I get mine from the local pharmacy and large containers of meths at a very reasonable price
BR,
Paul

[ian williams]

i used malt vinegar to do my flat tank , it wasnt full of chunky rust but had a coating of light rust inside ,
i had a gallon of malt vinegar inside and topped it up with some water to reach the filler neck , then left it for a week and checked it periodically , then another week of same .
came out very clean and plenty of rusty sediment in tank .

had to clean out the sediment from float bowl every so often when i was first riding the bike after all that but nothing major .

if you do the job like this on yours then id slosh some diesel in the tank after youve washed it out of the vinegar , to give inside an oily coating otherwise it will flash rust straight away .

i have just repaired/welded/soldered my NH tank , used tankcure rust cleaner and that wasnt too bad , but i then put in a slosh tank sealer after drying it all etc ,got to re spray the tank yet but should all be good again after ive done it and let it cure .
then happy days again
cheers
ian

[pappleton]

I bought a rusty VH tank at a swop meet and was warned it leaked. A good handful of granite chippings with soap and water and into a cement mixer, packed foam around the tank. The whole process took about a day, changing the position of the tank to get all the rust out. I then brazed up all the pin holes and made new mounting plates. I used the POR15 sealing kit as although not the cheapest, looked to be the most comprehensive - and another spell in the mixer for good measure. I did a basic pressure test , about 10psi with the tank filled with water. It's a long process, requiring a repaint as well, but I'm very happy with the finished result.
BR,
Paul

[cmattina]

I have so far been soaking a rusty oil tank in cleaning vinegar. I hit with red 3M scotch bright on a drill once a day. After 3 or 4 days it is looking quite good. Will share results once done.

I also bought some evaporust which is quite expensive. It does not work well at lower temps, but seems to be working about 70F (20C).