Car painting

[zahc]

The paint on my '96 Tahoe's hood peeled off, so I'm attempting a rattle-can remedy.

I don't have any sort of paint booth, so it's destined to be a hack job, but at least I should know how it SHOULD be done.

I stripped it down to the bare metal with paint stripper and wire brush, then sanded the whole thing with 220, cleaned it with windex, and sprayed on white primer. So now it's rough, dull white primer, with a few bugs. Before I spray on the white gloss 'real' paint, am I supposed to wet-sand the primer, or hit it with some steel wool or something? It seems really rough.

[Tallpine]

The hood is gloss white 

Why don't you unbolt it and paint it flat black?   

[Jim147]

It's been a few years since my summer in the body shop. White is a hard color to match.

You want to wet sand. You may need to prime it again depending on how it looked when you sanded it to steel. For the shake and spray they make different colors of primer. You wet sand one color and and then spray on another. When you wet sand the second coat it will show the first coat where it is high. If you can feather it smooth you are good. In the shop the grey always came out a little different shade so you could see the spots you needed to work on.

Is the hood on or off the truck? single pieces work better on a rack leaning about like an easel. Less dirt and easier to reach everything.

jim

[Monkeyleg]

220 is much too coarse for final finishing. You should go from 220 to 400 to 600 to 800 to 1000. If you're going for a really good finish, you'd want to continue with 1200, 1500, 2000 and 2500 grit.

Windex isn't suitable for cleaning prior to painting. There are cleaners specifically for painting. Unless you want to do this again soon, invest a few bucks in some cleaner.

Spray cans are going to give you a mix of wet spray in some spots, dry spray in others, orange peel, and everything else. If you don't want to rent or buy a spray gun or compressor, put extra coats of paint on the hood, and then sand them down smooth later (as in weeks later).

[zahc]

The truck is gloss white. So I bought 2 cans of "sandable primer" and 2 cans of gloss-white paint at NAPA.

I primed it but I haven't sanded the primer yet. The hood is off the truck.

I have a tiny pancake air compressor; I could buy a cheap spray-gun if it really makes a difference, however, I'm trying to decide if it's worth it since there's no way the color is going to match, and since I don't have a booth I'm sure there will be some crud in it. I'm thinking I will hit the primer with 600-grit (wet?) and then spray the paint on, then try to wet-sand the orange peel out of that. 

[Nick1911]

I rattle canned a motorcycle tank once.

Two coats of primer, two coats of color, several [2-4? don't remember] of clear.  I wet sanded with 600 between coats, and then took the final clear coat through 2000 grit, then rubbing compound, then polishing compound.  It looked nice for the crude tooling and my [lack of] skills.

Do yourself a favor and wear proper PPE, please.

Let each coat dry in a reasonable warm, low RH environment for at least few days each time, less the offgassing VOC's bubble up the next layer.

Practice a bit on some cardboard or something.  It sounds stupid, but it takes a little getting use to for good technique.

[zahc]

So when you wet-sand, do you just use a spray bottle of water and make sure the sandpaper and surface stay wet? I've never done it before. I'm more familiar with woodworking.

[Nick1911]

So when you wet-sand, do you just use a spray bottle of water and make sure the sandpaper and surface stay wet? I've never done it before. I'm more familiar with woodworking.

I don't know if it's the right way, but I had a bucket of water that I'd dunk my sandpaper in often.  If figured that would help carry away the particulate matter from the paper.

[Larry Ashcraft]

Hold a wet sponge above the area you are sanding and keep a constant dribble of water running down on the sandpaper.

[charby]

220 is much too coarse for final finishing. You should go from 220 to 400 to 600 to 800 to 1000. If you're going for a really good finish, you'd want to continue with 1200, 1500, 2000 and 2500 grit.

Windex isn't suitable for cleaning prior to painting. There are cleaners specifically for painting. Unless you want to do this again soon, invest a few bucks in some cleaner.

Spray cans are going to give you a mix of wet spray in some spots, dry spray in others, orange peel, and everything else. If you don't want to rent or buy a spray gun or compressor, put extra coats of paint on the hood, and then sand them down smooth later (as in weeks later).

I used naphtha and a cheese cloth for cleaning bare metal before paint. That was something I read on the back of a paint can on time.

Windex even has residues in it which could cause the paint to lift in time.

[zxcvbob]

It's been many years, but IIRC you wet sand the light-gray primer with something like 320 or 400 grit paper.

A hood is too big an area to paint with a spray can and have it look good.  Rent or borrow a spray gun, or just use a roller or a 4" brush and some tractor paint.

[Nick1911]

I've always been partial to brake parts cleaner for removing oils on bare metal.  Cheap, no residue, very volatile so it evaporates fast.

[Tallpine]

I've always been partial to brake parts cleaner for removing oils on bare metal.  Cheap, no residue, very volatile so it evaporates fast.

Or rubbing alcohol   

[Hawkmoon]

Or the products made for the job, such as Var-Sol or Prep-Sol.

[geronimotwo]

plenty of good advice here.   if i were using a shake-em-up can, i wouldn't be too worried about using anything more than 600 grit wet sanding.  you can use a hose to run the water while you are sanding.  i agree with the not using windex sentiment, it seems lacquer thinner was what i used back in shop class for bare metal, although there are some acid based etching products that help the paint grab better.  two coats of primer, and two coats of topcoat should hold up, and if the finish color doesn't match as well as you like napa can order the proper paint for a third.  wet sand between each coat just enough to take out the bugs, and spray your finish coat right after a good rain so the dust is settled.  good luck!

[zahc]

Well, live and learn. If I had it to do over I would probably have just rolled on some tractor paint with a foam roller.

Because i have no repirator I had to spray it with my garage windows open to get a good cross-breeze. No way to sand between coats since the cans said to recoat withon 1 hour or after 7 days, and i don't want my hood off that long. So i have a pretty complete but quite orange peely hood that looks a lot better than it did before. I figure i'll give it a week on the truck then wet-sand it with some 1200grit and maybe nu-finish.

[charby]

Well, live and learn. If I had it to do over I would probably have just rolled on some tractor paint with a foam roller.

Because i have no repirator I had to spray it with my garage windows open to get a good cross-breeze. No way to sand between coats since the cans said to recoat withon 1 hour or after 7 days, and i don't want my hood off that long. So i have a pretty complete but quite orange peely hood that looks a lot better than it did before. I figure i'll give it a week on the truck then wet-sand it with some 1200grit and maybe nu-finish.

I'd give it a good 2-3 weeks to cure before applying a rubbed on finish. Are you going to hit it with a clear coat when you are done painting?

[zahc]

Well, I have figured out that it takes 3 cans to put a good coat on this hood. The same brand of clear coat is $5.25 per can, so clear-coat would add over $15. Now that everyone is telling me it's going to peel off anyway since I didn't wipe it down with acetone first, I'm not sure I want to spend $15 to try to turn my sow's ear into a silk purse.

But the big thing is that I want my garage back, so this thing needs to go back on the truck. I'm not waiting around a couple weeks for it to cure before putting on another coat. I suppose I could take it back off the truck in a couple weeks and do the clear, but I know myself, and once it's back on the truck, it's going to stay there.

[geronimotwo]

if you decide to go with the tractor supply paint, the "roll and tip" method can give some pretty good results.  and yes, you should have good ventilation for that as well.

[Tallpine]

My new old pickup has bare metal and some surface rust above the windshield.

I'm thinking about hitting it with a wire brush on a drill, and then brush on some gray primer 

The top of the cab is very faded blue so it shouldn't stand out too much, certainly less than the rust color.  Not trying to make it pretty but just trying to keep it from becoming a convertible.


Any thoughts from anyone 

[RoadKingLarry]

Sand it down, mask it off and shoot it with some Rustoleum in a complimentary color. Many years ago I had a Ford LTD II with a vinyl top that was peeling and look like crap. I peeled it off, used a solvent to get the adhesive off sanded, primed and shot it with a brown that was close to the vinyl color. a little time with some hand glaze and it looked pretty good.

[zxcvbob]

My new old pickup has bare metal and some surface rust above the windshield. I'm thinking about hitting it with a wire brush on a drill, and then brush on some gray primer  The top of the cab is very faded blue so it shouldn't stand out too much, certainly less than the rust color.  Not trying to make it pretty but just trying to keep it from becoming a convertible.

I had a Subaru that I bought used with less than 100 miles on it; it had been in an accident and the dealer took it back in trade for another one, then then fixed it.  They did a piss-poor job of prepping it before they repainted the windshield pillar, so the paint bubbled-up and started to rust after about 2 years.  Right there by the rubber gasket.

I sanded it down and use Rustoleum rusty-red primer on the bare metal, which I could still see little dark spots of cancer that I didn't totally grind out.  Then used sandable gray primer over that, spot putty, and more gray primer.  Then painted with Duplicolor in a little spray can.  It not only looked good, but the rust never came back; the red primer killed it.

[geronimotwo]

zahc,  i am curious as to why you used windex to clean the hood?