Hitchcocks Forum

2nd and last question of the night, should I de-rust the inside of my petrol tank myself of pay someone to do it for me?

Hi Andrew, do it yourself! a handful of mixed nuts and bolts inside and give it a good shake followed by a dose of paraffin, repeat the process several times and that should do the trick, well it worked for me ! REgards Dick.

If you have access to a cement mixer, put some nuts and bolts in the tank, wrap in an old blanket and secure in mixer, tumble for 15 mins, turn round and tumble another 15.

I'm sure the "Mr Tumble" method will work with time but it has certain drawbacks; it is very slow, the gravel/shrapnel never seems to get right in the corners (which are often the rustiest bits,) and it leaves fine dust behind which can bypass filters and blocks main jets very well. I have an alternative which really works: get 2 tins (500g each I think) of Tate and Lyle's Black Treacle and dissolve in hot water making a solution of about 3 litres (4 pints). Add to tank (making sure tap is shut or hole bunged up firmly!) and add warm water to fill tank right up. Put cap on loosely. Mixture will start to work in a couple of days when it might create some foam, hence leaving the cap loose. When that's finished tighten cap and then leave tank somewhere warm and dry for 3-4 weeks. Speed of rust removal can be checked by looking through the neck occasionally. If it looks ok you can drain it and if you discover rust still present strain the mixture to remove rust flakes and put it back in. Keep level topped up if water evaporates. When happy with tank, drain liquid, flush with some boiling water (from a kettle) to remove any black loose rust scale and dry with a fan heater straight away, lightly coat with thin oil if not using immediately, the bare metal will surface rust very fast. I have used this technique several times and it really works. Snags; it is slow and if the tank is very rusty the mixture will eat through the rust all the way to the surface and the liquid will leak out so keep an eye on it! It won't touch healthy metal though and will not harm paint. You can also use the liquid to de-rust small parts or other tin ware if you can submerge it. Advantages are it's very cheap, very effective and will not harm the parent metal.

REgards, Mark

Well Mark, I thought you were pulling our legs but a quick Google proves you right.
I day without learning is a day wasted......

It's not April 1st, honest! This method really works, I wrote about it in the articles about about the Ebay Bullet (with pictures,) in The Royal Enfield Magazine online but I can't remember if that episode got published before the mag folded. I use it if the restoration is going to be a long one, one of the first jobs to set aside. Chemical stripping is much quicker and just as effective but will remove paint. You can get this done at places that restore furniture, doors etc as it's a varnish removal technique. I sometimes use this method when I'm getting blasting done anyway as my usual chap offers the service.

REgards, Mark

just cleaned a car petrol tank .

a couple of gallon of BRICK ACID block all holes turn the tank every hour for about 4hrs to make sure you get every part of the tank ,,,pore the acid back into its containers fill with water wash out then wash again with baking powder in water to neutralise the acid .

you can reuse the acid agin and it costs around £8 per gallon

john

I used agricultural molasses, diluted 20:1 with warm water and it will strip the rust of any ferrous metal in 10 days to two weeks. The genius of this is that it does no damage to any extant metal. The once rusty item comes out an even grey and completely clean of rust. It stinks to high heaven so do it outside under cover. It's obviously an effect of the sugar because I'm told Coca Cola works too. It takes a leap of faith to immerse a precious item into vat of wetness but you can have complete faith in the outcome.

Coca-cola dissolves teeth!

Oh yes good point. Don't leave your teeth in there.