Paint on rust converter

I would like to use a paint on rust converter to deal with surface rust on the underneath of my van. I have tried Loctite 7503 and Rust Doctor, but when I have used them before the rust still seems to come back under the paint despite carefully removing as much loose rust as possible, following instructions and using a red primer under top coat. Suggestions gratefully recieved.

Reply to
seabreeze
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Kurust works for me, but I know that underbodies can be hostile environments, and the exact type of paint over it makes a big difference. You might like to consider POR-15. The Dinitrol products also have good reviews. Have a look at

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and check out the "rust" link. Bear in mind though that Frost are not particularly cheap and you might find the same products locally too.

Reply to
asahartz

I have used a good product called Vactan. Get it off an eBay supplier (I do) or places such as

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or
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have used it on the children's cars -sills, suspension, brake pipes, backplates on rear drum brake and inside our cast iron house gutters. Easy to apply, not particularly hazardous to use like other solutions I have tried in the past and can be painted over without washing down etc.The daughters latest car was particularly rusty underneath so as a test I have painted all the rusty areas but not bothered with a top coat of paint just to see how it copes. The finish dries as a sort of plastic coating. Gio

Reply to
Gio

blast it with a sand blaster then use a zinc primer, this is the longest lasting method I have found

Reply to
Mrcheerful

There is no lasting cure, but I've got a car that is now 52 years old, and I have had it for the last 23 years and paint (by squirting) the underneath with old engine oil every two years. A bit messy but costs nothing and works like a dream.

Rob Graham

Reply to
Rob graham

People complain about the build quality of Britsh cars but this type of automatic car body underseal system using engine or transmission oil used to be a standard feature.

Reply to
adder1969

Basically don't waste your time because no rust converter deals with all the rust present and any left will quickly start to spread again under the paint. The only sure method is abrasive cleaning i.e. sand blasting which gets into the pores as well as removing the visible surface rust and then use a good primer, zinc usually, before painting over.

The rules for dealing with rust, in anything, are get every part back to clean bright metal and then prime and paint before new rust starts to take hold again which can be within hours in the right environment. I think anyone who's messed about with vehicles over a number of years has tried and failed to cure rust long term with converters, wire brushes, disc sanders or any other method that doesn't use fine abrasive particles to get into all the surface pores.

Reply to
Dave Baker

Absolutely true; my '71 Mini is a fine example of this! And there's no rust whatsoever underneath.

Reply to
asahartz

I've got to agree with Dave here. An 80 grit sanding disk or a wire brush will make a pretty good job if it's a flat panel, but if you've got anything else, the best way is to blast it clean.

Reply to
Doki

If it were the underneath of my van I'd just slap loads of waxoyl underseal on it.

Reply to
adder1969

I looked at the Vactan product on the net and it seems to be pretty good. I don't have access to a sandblaster unfortunately, so will try this and see how it goes. Thanks for replies.

Reply to
seabreeze

Hope you find it OK. Can you let us know how you go on and if it works ok ?

Gio

Reply to
Gio

I spray the oil using an air compressor to make a faster job of it, especially as its an old VW campervan and a lot to cover. A proper spraying face mask is advisable and to be aware its very flamable when spraying. Obviously the high air pressure is very good at getting into box section and chassis. Just have to be carefull to avoid pointing at brakes and clutch. I also try to avoid getting oil on the rubber components in case it affects them. I know engine oil used to make rubber parts deteriote, but not sure if that is still the case with synthetic rubbers used today. With old and dried out rubber parts its debatable if the oil actually helps as stops them drying out and cracking. My van rarely moves, but if it was being driven I'd want to wash the tyre tread to remove any oil that might have got on it. I use new engine oil, but suppose old stuff is just as good. I also put some around the lower body to protect it over the winter, but use those little domestic syphon sprayers (type used to spray car wax) for this job. The ones I have will not atomise the oil, so I mix it with water and washing up liquid and after the water has evaporated off, the oil leaves a nice protecting film over the paintwork. Its also very good at making the grey plastic bumpers jet black again. Easy to go around and do a quick squirt mid winter with the syphon if needed.

Graham

Reply to
Graham Harvest

Yes, I agree. In fact, this is what I do.

A proper spraying

No. But I've never had a problem with this.

With old and dried

I have no problem with old oil, and anyway, it's free!

Rob Graham

Reply to
Rob graham

i am afraid that theres only one way to get rid of rust ant that is to remove it by shot blasting, grinding or any other abrasive method you can think of and prime it as soon as possible in a dry enviroment, i have worked in the shipbuilding industry for years and its the only way to go , dont waste your money on these treatments , grind it out, prime then fill , prime again then paint , if not it will come back , maybe not right away but it will , good luck

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Reply to
shane van-outen

Many car body fillers require you not to prime the metal first as they bond to the steel

Reply to
steve robinson

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