O/T: Ping Michael Hurd -- Car Painting Question

[Olorin]

I suppose this could be a PM, but then I'm probably not the only one with rust on his car . . .

I'm hoping you can make a recommendation or two for a good rust

inhibitor. Rust Bullet, POR-15 any good? Other better ones

out there? I have some surface rust where rock chips have been

left unexposed for too long, and I'd like to take the areas down to

bare metal and put some kind of protectant on before the primer.

I have a neighbor who works for a restoration shop, and he's agreed to

do the finishing work for me, but in order to keep the cost in the

case-of-beer range I need to do the prep work myself. I

appreciate any input you might have.

O

[colterphoto1]

I wipe mine down with rancid pole-cats.

But MH will have a more popular and longer lasting idea.

M

[Duke Spinner]

por 15 ... just covers it up ...

me, personally, would spotblast, and use a true rust converter like Ras-o-Nil ....

don't fall for thr bogus claims made for somma those "convertors ... like Wynn's...Crap in a Can

[Olorin]

I wipe mine down with rancid pole-cats.

But MH will have a more popular and longer lasting idea.

M

I hope so. If not maybe I can borrow a horny goat.

[michael hurd]

Been away working on a rust repair project of my own, an '82 chevy 4x4 for plow duty.

Are you sure that prepping it yourself is actually going to save you money? I am not doubting your abilities and skill level, but if you are planning a repair of a basecoat-clearcoat surface, there are several things you need to know, especially in selecting an abrasive system.

If there are many rock chips, especially in a hood panel, the best method of repair is to strip at least the very worst portion at the front, either with a chemical stripper, or 80 grit on a dual action sander.

This way, you can eliminate all the chips, and have only one feathered edge, rather than multiple spots. This is the best repair, requiring primer and primer-surfacer application.

If after stripping with 80 grit, there are still small rust blotches, a 3M rust n' strip wheel on a drill will remove any spots ( watch how long you use it on any one spot- heat builds very quickly )

The reason I mentioned that it is not really cost effective, is that you have to purchase all the supplies, rather than a shop that can mix up small quantities of primer + primer surfacer. You would also need masking supplies, tape and paper. Add in the cost of sandpaper, etc, it can get expensive.

Sandblasting is great, but not on a hood panel, especially a newer honda, I think it is either 24 or 26 gauge metal, a little thicker than a pop can. If you blasted a spot on a honda hood, you'd be throwing it in the dump after, it would warp so badly.

If you still want to prep it yourself, I can give you more info on sandpaper selection and use.

[Duke Spinner]

SpotBlast, Michael ...!

not Sandblast the whole car ...

are you familiar with Ras-o-Nil ..??

eh ..??...[]

[michael hurd]

Even spot blasting is enough heat to severly warp thin late model sheet metal. If used with care, can be used around wheel arches, etc. I have 2 small handheld blasters, one has a baggie and various soft rubber cups for recovery of sand.

[michael hurd]

There are some instances where I have used Rust-mort, a chemical converter, but I usually reserve a "converter" as a last resort.

Before sanding anything, wash the car with hot soapy water and rinse clean with water, this will remove any water-soluble contaminents before they get ground into the finish. You should also use a solvent based wax and grease remover to take off any petroleum based contaminents as well.

Progression of sanding - p80 grit to strip to bare and start a feather edge, p180 to feather edge, p320-400 grit to "backsand" around the feathered edge so that primer surfacer has something to bite into, then overall sand the rest of the panel with p-600.

Apply a zinc chromate containing epoxy primer as a pre-coat, then 2-3 coats of primer surfacer. Sand the primer surfacer after it cures with p400, then p600, and lightly scuff with a grey scotchbrite pad.

[Duke Spinner]

Dude ...

research the Rass ..

i use it constantly on rusted sheetmetal ...it's not a "converter" in

the sense that you are thinking, rather, a 'preventer" of re-occurence

[Olorin]

Hi Michael,

Thanks for the response. The vehicle is a '97 Toyota Land

Cruiser, so it's a bit heavier duty than a Honda. ;-) If

I'm understanding you correctly you're not a big fan of the rust

products at all but prefer removal by abrasion followed by covering

with a good primer and painting. Is that right?

The rust is confined to three small areas, spots really, none larger

than 1/8" in diameter, and all on the roof where nobody will see them

unless I put the truck shiny side down. I'm more interested in

protecting the metal and stopping the cancer spreading, since I mean to

keep the truck for a long time.

What you say about tools and supplies makes since. I once spent

$1000 dollars on tools and lumber, and six weeks later I had a $600

aquarium stand. The upside is that now I have tools, but I can

see a lot more opportunities to use a table saw than to use car

painting supplies. It probably would be good to have a body shop

give an estimate in any case.

Thanks again.

[michael hurd]

Sounds like a good candidate for removal with a 3M rust and strip wheel, kind of a heavy duty scotchbrite. ( coarse nylon weave with bonded abrasives )

If all you are painting is the roof, then it is not too bad to fix, especially if there is only 3 spots. Feather out the spots with p80 and p180 on a dual action sander, then finish the feather edge with p320-400 and backsand around the feather edge so that the new primer and primer surfacer has something to stick to.

As long as the rest of the paint on the roof is in good condition, it can be prepped either by sanding with p600 grit paper or a specialized sanding paste. ( used with water and a grey scotchbrite pad )

I use Glasurit Sandfix paste and a grey scotchbrite for scuffing clearcoat, it is a clay and abrasive compound that is water soluble. Unlike sandpaper, it will scuff down to the bottom of slight orange peel, where sandpaper will only remove the high spots, leaving shiny spots at the bottom of the peel.

You could prep most of the roof yourself in about 45 minutes - 1 hr with a sanding paste, then all you have to do is wash off the residue with soap and water. The important thing to remember when using the paste is that you need to progress gradually down the vehicle, keeping the stroke in the same direction, applying slight pressure.

You may find some spots that were not scuffed well enough, in your first time using it, but with practice you get better, kind of like washing a car, you always seem to miss spots unless you go at it and really pay attention.

Pay attention to around the windshield reveal molding, here I would use p600 sandpaper, so that you have greater adhesion, less chance of peeling from a rock impact in the future.

You can pick up some supplies, like a sanding paste, ( Glasurit Sandfix is about ~ $ 30 cdn for a tube, enough to prep several vehicles ) and grey scotchbrite pads at a bodyshop supply house. Cut or tear the scotchbrite in half, then dampen with water and apply a golfball sized amount of paste.

As for primer and primer surfacer, there is nothing in a spraybomb that I would ever consider using, you must also use a system, so that the materials are compatable. ( same manufactuer of primer, primer surfacer, and paint materials )

You do not want to experiment mixing and matching, you may not have any problems, and then again you may. Best to stick with one brand from bare metal through topcoat.

[Olorin]

Thanks Michael. I'm clearly well-intentioned but over my head. I'll take it to a shop.

[Cal Blacksmith]

The best thing I can tell you to do is..... Sell the car, house and most everything else and move somewhere that is warm and out of the snow and salt. Buy a new house, stuff and car and enjoy it long after the payments stop!![][][]

Edit: I see you have done most everything I said as you are in Central Ca, I guess you need to stop visiting where there is snow and rust!