when priming my truck can i use rustoleum rustprofing primer under my paint job or do i have to spray it over with a automotive primer.

 

Depends on the outcome you want. If you are using aeresol can spray paint to finish coat the truck, go for the aeresol rustoleum primer. If you are spending hundreds or even thousands for a new single stage, base / clear, or even enamel, go with the automotive primer compatable with your paint brand.

 

If your just doin' a temp. job (spot repairs) 'till you get the whole thing painted, then I wouldn't waste money on pricey rustoleum! Just dust on some cheap-o primer and cover the spots with some cheap-o spray can paint. Remember what you read in the very first post........... what! you didn't read all the replies????? Well suffice to say,PRIMER is NOT waterproof, so ya gotta cover it with some kind of topcoat. And since spray can stuff is not compatible with pro. auto paints, ya gotta sand it off before ya get it painted.

 

Acrylic Enamal auto body paint will stick to the rustoleum primer just fine. So will automotive lacquers. The other types of auto body paint do not seem to adhere very well.

Do note that the rustoleum primer does not go on as smooth as auto body primer, so your final finish even with top quality automotive paint isn't going to look very good.

Ask me how I know

 

Im doing all the body work so for the frame and bottom of the body i wanted to spray a rustoleum. I figures i would cover the whole truck top to bottom in rustoleum, sand it with 220, then put a automotive primer that is commpatible for the paint to stick to and sand it with 400, then take it to get painted. The paint will be a base/clear coat.

 

For the frame and the underside, I wouldn't even bother with auto body paint and primer, I'd prime it with rustoleum and paint it with rustoleum, because rustoleum has two obvious weaknesses over auto body paint - it's not UV tolerant for any length of time, and it cannot produce a nice as finish as the super-fine auto body paints.

But for a frame and the bottom side of the truck, who cares! You'll only see it while changing u-joints and mufflers anyway.

 

The main reason i want to use rustoleum is because it takes care of rust. It should be ok if the first coat is rustoleum, and the coats over it are automotive primer. Because when i put automotive primer over the rustoleum it will blend together.

 

When I did my frame over a few weeks back I sandblasted off all the loose rust flakes, then brushed on a product called "Ospho", which converts iron oxide (rust) to Iron Phosphate, which makes for a strong primer. The Ospho essentially seals the rust to prevent further disintegration of the metal, and makes an excellent primer too, though I primed over it anyway.

I used two bottles of Ospho to coat my frame, and the underside of the truck, various suspension members, the cross members, and the inside of "Superbumper", and I had some left over. It's very watery and goes on easy with a paintbrush. I prefer this product over thicker products because it is so watery - you can let it "run" in between rivited joints of crossmembers on the frame, getting a better seal. Products like POR15, which excellent, don't "wick" in between things as nicely as the Ospho. Plus, the Ospho was only $10 a bottle, for a total cost of $20.

And it doesn't eat plastic, so you can let it drip onto a plastic tarp or your driveway, and it's not going to ruin it. POR15 sticks to everything

 

I would sand with finer than 220. It will leave scratches. Sand with 600 on the primer, and then the top coat will be smoother. If you want to see what rustoleum can do, look in my galleries. The only problem I had was the quick dry clearcoat. It sucks, and messed up my otherwise flawless sprayjob.

 

Spray bomb paints do NOT have the bonding strength and longevity of the auto paints ( that is why auto paints cost so much, the research, testing, and manufacturing of the product costs) . All auto paint systems recommend using their total product line, start to finish. That way a person and the paint jobber, are assured there is no failures down the road from what is called product "incompatibility". ...

Therefore when the spray bomb paint is applied , and the quality auto paint is put over it, the weakest link in the paint system is the spray bomb paint. Spray bomb paint has its limitations as any product, they are meant for small projects. The total paint coat system is only as strong as the weakest link in it, whether that be cleaniness, prep, or product integrity. Not coming down on anyone for using it, I know money doesnt come easy, but it all depends on what one has to spend and what the TOTAL outcome is they want on their project . I used the spray bombs on a few of my engine compartment components, because they were not worth breaking out the fresh air system and spray guns to do bc/cc on. They look good today, but are basicaly out of the weather , under the hood. So, not all applications fit everyones budget needless to say, use them well . But do not have great expectations from them , when compared to automotive professional finishes...

Be not decieved by the marketing strategies of the much acclaimed rust "stoppers". The only way to impend rust is to, as Frederic notes below, is to convert it. These "rustpaints " are just covering up the rust, which do impede oxidation , therefore slows the rusting process, but the rust is still under there growing like a clump of grass. Phosphuric acid, Picklex 20 ( what I used on my truck and love to keep using) will provide a good conversion for a paint substrate. If I could do my chassis over , I would just use Picklex or Osphos on it, then apply a matte black Zero Rust . ...

Just some info for those starting out on their projects, and there are few shortcuts that will work out in the long run. The paint on a vehicle is the final , most expensive and most prevailing detail , that one sees first, when they walk up to the vehicle. A bad paint job will make that 4k chrome covered crate engine sitting in a truck, look like a VW engine on crack. There are few things more disheartening than to have a two year old paint job fail. all jmo and good luck to all on their projects

 

hey thanks for the information im just a first timer at this stuff.

 

So Greg,

I'm taking the first step toward repainting my '60. I want a plain-o daily driver job, no metallics or anything special. I'm going to use acrylic enamel. My truck has quite a bit of rust on its horizontal surfaces (nowhere near rust-through but pitted). After I sand to bare metal, you're saying I should use the Picklex 20 on the rust. So far so good.

I'll be doing some bodywork, etc. over the next month or two before I can get it painted. During this time, the truck has to set outside, no choice. What kind of primer should I use to protect the bare treated metal from rust in the meantime?

 

use a product called "Ospho". It's available at most hardware stores, specifically home depot and Ace Hardware. It's about $10 a quart, and one and a half quarts was all I needed to do my crewcab's frame, inside and out.

It's better than rustoleum because it doesn't just coat the rust, but rather it converts iron oxide (rust) chemically into iron phosphate, which you can paint right over.

So slather it on both sides, and along the edges, let it dry, then rattle can it with any color you like, as you'll be repairing the rust later. Iv'e been using this substance for years, and it's good stuff.

And it has the consistancy of water, so you can dab quite a bit of it into seams between body panels (that are spot welded), seams between cross members and frames, all the places that por 15 would just sit on the surface... this stuff digs right in.

And it doesn't eat plastic, your asphalt driveway. Just don't get it on your hands, it does stain skin. And it eats latex, so don't use latex gloves, wear leather or rubber gloves. I use rubber kitchen gloves.

 

If you use the picklex 20 be sure to apply it exactly PER the instructions for best results. Fredirics osphos works well too. If the truck HAS to sit outside, I would at least put a tarp over it if possible , and anchor the tarp well. Even those will leak after a while though. The P20 will hold off most rust , but on that much bare metal you could still end up with a dusting of surface rust all over, that would have to be sanded off prior to priming. Your paint supplier also carries products for bare metal protection that will be compatible for your paint I would think. Stop in and talk to them about what your wanting to do. Getting a repore with your paint supplier guys always helps out in the long haul. We end up needing their advice more than we think sometimes...

Some people prime their vehicles while waiting for topcoat with a two part epoxy primer. Epoxy primer is popular for the first coat of primer because of its good adhesion to raw metal, corrosion resistance, and sealing properties. The epoxy can be scuffed and filled over if more filler is needed prior to topcoating. It is a bit pricey ( what auto paint isn't ? ) but worth it, and it does use a hardener , so you will need a fresh air supply breathing system , or at minimum a good charcoal canister mask with prefilters to spray it if you use epoxy primer. ..

If you go charcoal mask, be sure it fits well and change the filter out after each day. These isocyanate based hardeners used in todays auto paints are SERIOUSLY dangerous ! I love my fresh air supply with the hood, because it protects my eyes and facial skin too, and I dont have to worry about a facial mask seal leaking. Also , the epoxy primer , having cured beyond its recoat window on stored vehicles, will have to be "scuffed" all over , prior to topcoating, so the 2k primer or sealer will have "tooth" to stick to. Auto painting is pretty involved and not near as easy as it is percieved to be , because there are so many ways to do things from start to finish. I am just a one timer DIY'er that learned how to do it from reading paint forums on the net. It has been a 3 year long, expensive, and stressful learning curve, but kinda cool too. Good luck to you and work safe, . all jmo

 

Im planning on just spraying rustoleum on the underside of the body and frame. Im going to put rustoleum around the window seals because of minor surface rust, after i fixing it with sandblasting