Rust

[decoupage22]

I am very excited cos I am about to get a moggie, however I would be very grateful if I could have some advice on how to treat rust, firstly on the interior floor panels, do I wire brush off the worst and then wet and dry to expose clean metal. What rust killer should I use, is rust bullet the best? Then can I paint and what kind of paint should I be using.
Please feel free to spell anything out, I am grateful in advance for the advice.
Glenn

[dp]

Hi,
I#m sure others will advise in more detail soon but generally, wire brush off worst, use a rust killer on exposed metal then zinc based/etch primer and then topcoat of choice. Hollow sections should be thoroughly waxoyled.

[bmcecosse]

Surface rust can be treated with rust killer - many are phosphoric acid based. But any rust coming through from the other side - needs to be cut out and replaced with new metal.

[GeorgeHurst]

Hi Glenn,
I would advise, for surface rust, cleaning back as best you can with a wire brush, then using a rust killer, and then wire brushing it again to take it back to bare metal... I did wire brush and then rust kill then paint on my bootlid and the rust has just come back under the paint after 2 years. So I would say bare metal or nothing!
As the others said, then use a zinc primer before a primer and top coat.
HTH
George

[Ted]

RE: Rust. This would have to be the greatest enemy of old cars. When rust has eaten thru a section, plastic body filler is not a rust repair method. It needs to be cut back to sound material and a section of new steel welded in.
If the rust is surface, then the best methods of dealing with it is, after removing paint and cleaning as much of the light rust as possible by sanding or wire brushing, is to use a rust removing/neutralising agent such as Phosphoric acid and treating after with Zinc phosphate, this needs to be wiped clean after treatment with a damp cloth and thoroughly dried to prevent any further acidic action. Painting [or coating with a suitable agent] as soon as possible after this, is essential to ensure rust film re-occuring.
Some non essential areas that may be pitted can be treated by a propriety brand rust stop product that has an affinity to rust such as POR-15 [USA]
Unfortunately some areas are inaccessable for both inspection or treatment. Providing there is reason to believe that they are quite sound, these can be treated by a variety of products that coat the surfaces and prevent rust. Some of them actually penetrate the microscopic pores of the metal and after curing, form a varnish like protective coating.
Most of these are not expensive and can be poured or sprayed with a wand into hard to get areas. Products like Penetrol, Fisholene, ['Great Stuff'! Made from fish oil.] Or Bilt-Hambers [UK] products. Check out the internet ! ! Ted

[bmcecosse]

Most would use Waxoyl in the UK - warm it and thin it slightly with white spirit - and spray it into every closed cavity you can find!

[chickenjohn]

Hi Glenn,
I would advise, for surface rust, cleaning back as best you can with a wire brush, then using a rust killer, and then wire brushing it again to take it back to bare metal... I did wire brush and then rust kill then paint on my bootlid and the rust has just come back under the paint after 2 years. So I would say bare metal or nothing!
As the others said, then use a zinc primer before a primer and top coat.
HTH
George

This is exactly my experience! You have to get rid of all the rust on your floor pans or it will come back. Use wire brush on grinder and drill. Apply 5-10% phosphoric acid solution, let it soak for a while (phosphoric acid dissolves rust but leaves steel) and keep wire brushing till all the rust is gone! Rust converters are basically rubbish and just convert the top layer. The rust is still there eating your car. Try a converter and scratch the surface and you will find brown rust underneath.

If you have a compressor, a spot blaster is useful for getting into the rust pits and cleaning them out.

So, yes, bare rust free metal or nothing!

[GeorgeHurst]

My step Dad works for a chemical company, so I have a big tub of 20% phos acid in my workshop waiting to nail the rust on my floorpan