rust combat, 2nd installment, 1st phase

you'll need a corded drill motor and a steel brush, and even that won't get all the rust out of the pits.

Rust-Oleum alone will probably not hold the rust at bay; if you find a rust converter product that you like use that first. Otherwise I'd suggest POR-15 or similar? (PITA to use but the rust won't come back)

if you have rust at the door bottoms you're probably going to have to pull the door panels and clean/POR-15 the insides of the doors

good luck

nate

Remember that what you see is only a small portion of what is actually there. Once you start a project like this, you may find that what looked like surface rust is really perforated through the metal and then you have to decide whether to take on a much larger project.

you're speculating, not speaking from experience. that's "not helpful".

rustoleum /IS/ a "rust converter product". see above.

no, do NOT mix products.

as opposed to "doesn't come back - i've used it and know"??? because you clearly don't.

you're playing whack-a-mole in that situation because those rust spots are typically penetration from the inside, not something that working outside can significantly help. unless you want to re-skin the doors and remove the fenders to get at their internals, it's hard/impossible to cure. so, if this really is a beater, and it were my beater, i'd hose the heck out of everything i could to wash out residual salt, then when dry, i'd simply spray atf inside the doors and up under the fenders as best as i could, then leave it.

yes, you'll have an "environmental impact" with run-off, and you won't want to leave the thing on your driveway for a few weeks, and you'll have dirt accumulation on paint where it continues to seep. but it's technically effective if you don't mind the cosmetics. [try not to get it on rubber components.]

If you're just knocking the loose stuff off and spraying on some paint to make it presentable then get a cheap drill and a couple stiff wire brushes. One cup shape and one disc. Use the cup shape in places like door seams and edges where the disc shape doesn't work well.

That will knock the loose stuff off and remove most of the rust. Now treat the rusted spots with a rust converter or neutralizer. LOT's of them out there.

The ones that turn the rust "into a hard paintable surface" use tannic acid and a "polymer compound" They are water based and HAVE to have some rust to work. That is also the reason they fail most of the time. If you don't leave enough rust so the acid can convert it and the coating cannot adhere it fails BUT if you leave excessive rust the acid cannot convert all of it and rust comes back in a few weeks.

Neutralizers also use acid, 99% of the time it is nothing more than phosphoric acid and water. With that you apply some let it set for a minute or two and wipe it off. I like to use a scotch bright pad to work it into the surface and kill as much of the rust as possible. Then a coat of etch primer, epoxy and paint...

up shape and one

e doesn't work well.

No, I would like to postpone a trip to my body shop mechanic to replace fenders and doors when rust eats through them. I don't care much about the appearance on that car since I keep dodging the annual technical inspections.

thanks

id and a "polymer

s also the reason

n convert it and

id cannot convert

horic acid and

t off. I like to

the idea being that scotch_bright-like pad will leave enough rust behind for converter to work and wet or dry won't?

the larger project being what?

Cutting out the bad sections of metal and welding in new

nate

This is very odd sounding. What openings? Sealing off drains or openings at the lowests points (outside of those that get a lot of spray from the wheels) accelerates rust. When I am fighting off rust I have on occasion added drain holes to the area as part of the treatment, allowing the water that gets somewhere it shouldn't drain out. I do go looking for the point of entry and seal it, but that search may or may not be successful. A well placed drain hole along with treating / repairing the rust does wonders for slowing/stopping it.

shape and one

doesn't work well.

and a "polymer

also the reason

convert it and

cannot convert

phosphoric acid and

off. I like to

The scotch brite will help the converter dig into the rust and kill all of it. ANY left behind will just start to grow again.

Then use some good primer and topcoat. Done right will stop the rust for a couple years or more.

Good catch, I missed that and you're absolutely correct.

However, I would seal the area where the skin is crimped over the inner from the inside with something - tar, POR-15, whatever.

nate

I've had excellent results using polyester resin and fiberglass to fix some significantly rusted spots when located where they can't be seen in normal use. Floor pans, trunk pans. I wirebrush then spray with rust converter, then do the resin repair. I'm not skilled enough for the patch panel work and even if I was, the resin is far far faster. When done right the bottom surface, like the underside of floor pans, can look like it's still all metal once you spray paint/undercoat it I put duct tape on the underside before applying the fiberglass/resin combo to the top side. When it's all cured the duct tape comes off and it's a nice looking outer surface. My memory is fuzzy but I think the last time I did this some of the rust thru holes were as big as a quarter inch and quite a few of them.

One very long lasting repair I made was in the rear shock tower of a car. First the usual treatement of rust removal, sanding, and painting with a rust preventing paint. It was before I had a welder, wasn't even my car at the time. I made a patch panel of galvanized sheet steel. Attached it with screws and pop rivets. Then coated it with structural fiberglass in the wheel well. Further topped it with undercoating.

The rust was stopped dead. The repair went until the car's end of life a good decade plus later. That is of course if someone down the ownership tree didn't put it back on the road.

I normally just weld in a patch panel now. In some limited instances I'll still use fiberglass. Using galvanized steel helps kill the rust too. It does give some limited protection to the very immediate area.

You think I'd get away with the cheapest ATF I could find around here or there is some compelling reason not to pinch pennies in this instance?

A lot of people use drain oil, probably has some corrosive combustion byproducts in it but still better than nothing at all.

nate

a lot of people??? use drain oil??? nate, you're a complete freakin' retard. most people use nothing. the very few that use "something" usually spend money of stuff like waxoyl or spray-on underseal.

of the vanishingly few that use any kind of oil at all, the ones that have done it twice don't want to re-block their spray gear with sludge and crap from used anything. and that of course speaks to your lack of experience and the anosognosic brain damage that prevents you from ever keeping your mouth shut about stuff you don't know.

from drained atf???

i look forward to the day when "nothing at all" is your only "contribution" to cyberspace. you're a total waste of electrons.

open the bottles on a couple of different brands and sniff. the cheap stuff doesn't have the same additive package and stinks less. the good stuff should shrivel nose hair. since the additives are part of the reason to use it, i'd spring the money and buy the one with more of them.

scotchbrite may well be fine for this work, but i have a very strong negative opinion about using that stuff on anything automotive and mechanical and won't allow it anywhere near any of my vehicles.

scotchbrite is basically an alumina abrasive held in a polymer matrix. ok fine so far. but the problem is that that alumina, unlike the traditional abrasive you see on wet-n-dry paper and grinding wheels, is not the granular type, but it has a "spicular" morphology. [look up "spicule" on the net.]

these spicules embed themselves into metal surfaces and are not easily removed. they do however like to embed themselves in skin, and then into metal somewhere other than where it was originally removed. thus, you can easily have a component completely cross-contaminated with that stuff just by handling. and because it embeds and is thus persistent, significant wear of otherwise "clean" components results.

i know this because back in the day, i was doing some bearing failure analysis, and under the microscope, you could see not just the embedded spicules and the damage they'd caused, but most tellingly, their deposit pattern was the exact pattern of a human fingerprint.

so, i know that stuff is sold extensively for use in automotive repair, but it's a classic example of vendor misapplication and where a repairer doesn't get to see the consequences of what they did. or worse, doesn't join the dots between action and result.

bottom line, scotchbrite has no place in automotive/machine work. don't use it.

"Couldn't" know.

Few are more fond than Nate of purporting to know what they have no method of learning, and which easily observable evidence contradicts. -----

- gpsman