Morris Minor Owners Club

For many years I have been using a phosphoric rust convertor as a first coating on surface rust, it works, its very similar in chemical terms to a few famous makes that are sold at incredibly high prices for a tiny quantity, this stuff is used in the Merchant navy and also Royal navy, and its at sea where you get the worst rust! It can be purchased in gallon containers for about £25 or less, enough to last you a lifetime! It converts the iron oxide into black (or white depending on the formulation) phosphate (FePO4), it comes in gel or liquid form and its environmentally safe, dilute you could,( although I do not recommend this) drink it without harm! Kurust and the like are starting to become difficult to get, as most modern cars expire mechanically before needing it, try it, share it !

It's for sale on Ebay

Phosphoric acid has long been the 'magic' ingredient.......but should it then be covered in waxoyl - or is waxoyl alone a suitable preventive on rusty metal ??

Its only a 'convertor' and if the subsequent coating is unprotected it will eventually rust again, its water dilutable so will easily wash off. What you should do is follow through with red oxide, undercoat, top coat and then and only then, wax or some other protection, I never get the rust returning! I have had the top of the tin containing the waxoyl type stuff produce surface rust (even after top spillages!) so I do not have that much confidence in the stuff on its own, I usually mix it with the following: 20% diesel (red is cheaper!) which helps it 'creep' particularly when doing inside box sections, doors etc and it is considerably cheaper than white spirit, 10% unused engine oil, 30% bodyshutz or something similar and the rest wax based protector of which waxoyl is probably the best, the bodyshutz gives it a black or white colour (other shades are available I believe) and helps it stick long term against road much/water as using waxoyl on its own is easily washed off. Experimenting with different proportions of the above is what I have done for 30 years or more, but the mix I have given seems to be the best compromise. Do not use bodyshutz or similar just on its own, it captures water and you will end up with a worse problem than you started with! If you are spraying this mix, which is the best way, make sure you are wearing a protective mask, its all toxic to your lungs. Sam

Phosphoric acid should be used to make sure you have really removed all the rust from the pits. I.E. wire brush on grinder or drill to get all the visible rust off then brush on the 5% phosphoric acid solution. Any bits that turn black are rust puts and need more wire brushing (or better spot blasting). Keep going till the pits no longer turn black, then you can etch prime and paint as required.

Never use anything that claims to be a rust " converter", these claims are rubbish, "converters" do not work, they just hide the rust underneath.

chickenjohn wrote:Phosphoric acid should be used to make sure you have really removed all the rust from the pits. I.E. wire brush on grinder or drill to get all the visible rust off then brush on the 5% phosphoric acid solution. Any bits that turn black are rust puts and need more wire brushing (or better spot blasting). Keep going till the pits no longer turn black, then you can etch prime and paint as required.

Never use anything that claims to be a rust " converter", these claims are rubbish, "converters" do not work, they just hide the rust underneath.

Well done for putting rust removal in a nut shell. There is now no excuse for further discussion about magic remedies!

I'm shocked to hear that waxoyl on it's own won't 'kill rust' - as claimed recently in a long and complicated and repetitive thread.........