Technical Paint chassis

So can i paint the frame without doing a coat of primer, meaning use only Rustolem oil based enamel in a quart, on top of clean surface rust? Or were you referring to only using 2 coats of oil primer on clean metal with some surface rust? You were saying that the oil based will act as a primer, but i am not sure if you were referring to an oil based enamel or primer??

I would ***ume 'if' i use a little bit of hardener with the oil based enamel then it would increase bonding on clean surface rusted frame?

I maybe over thinking this ,but that how a person learns ask questions, lol lots of them.

If i do have and need to use a primer, can i paint over the primer with enamel without scuffing the surface of the primer? The reason i ask is there's some places I will not be able to sand, because of the limited (reach) access i have to all 100% of the frame. N

 

If you want to brush, just mix smaller portions of paint.

HVLP mix ratio for rustoleum
8-4-1, 8 parts paint, 4 parts reducer, 1 part acrylic enamel hardener

Reducers - real enamel reducer works the best, you can control the drying speed and its a better product. If speed is important, step up to a real enamel reducer.
If you want to use others.
Acetone is fastest, naphtha is medium, mineral spirits is very slow.

Hardener, I use valspar enamel hardener or any generic enamel hardener from paint suppliers.

With a fast enamel reducer or acetone, the rustoleum "should" set up enough to recoat same day. It will take days to fully cure out hard. But you're not trying to sand or buff it.

Rust converters.....everyone I've used has been ****. It either bleeds back thru the paint or causes some interaction at a later date, or it just doesn't work, the rust comes back thru later.
Most rust converters are a weak mix of acid.

I've started using the "real deal" phosphoric acid, look for concrete cleaner. Klean Strip concrete amd metal cleaner is a common brand in stores.
Spray it on with a good spray bottle. Let it sit and work, neutralize with a mix of baking soda and soap. I flush with rubbing alcohol later because it evaporates fast. You can use water but get it dry with air quickly. The phosphoric acid turns the surface to a black oxide coat as intended.

You mentioned 97 chevy truck. If there's remains of the factory wax coating, it will prevent paint from sticking.
**if the frame has flaky rust, the flakes need to be knocked off. Just wire wheeling the top layer when its flaking from the actual frame will cause problems later. Use an air chisel with a blunt tip. Wire wheel as much as possible, cleaning a frame in the vehicle ****s bad.

For reference:
I shoot a lot of rustoleum and industrial enamel. Recommended mix ratio is above, I use a little less reducer, and tip in some hardener.

I use the same mix ratio on any industrial (alkyd) enamel. I hate rattle cans and prefer not to brush. Been using sherwin wiliams and rustoleum semi gloss enamel on furniture and cabinet refinishing, really any time I need to paint. I try to spray it.

(I shot a piece of furniture with rustoleum satin white, acetone, hardener this winter - cold garage. I was able to shoot one side and flip it about 16 hours later, dry enough to handle and rest on the painted surface in a 50 degree garage)
Warm temps will help it cure enough for a recoat.

 

The last 4 or 5 frames I've painted I used the Rustoleum enamel right out of the can, nothing added. Two coats, with a week between.

The week before painting, I cleaned the frame as best as I could. I removed all the crusty metal I could with an air chisel with a blunt tip. Then I sanded everything I could reach with 80 grit on a sander. Then I followed that up with a metal prep cleaning spray mixed in a spray bottle. Time spent preparing the frame is the best time you will spend, and it shows in the final outcome. The frame sat in my garage all 3 weeks, from the cleanup through the 2nd paint coat, and at least a full day after the second coat was finished. For the record, I put lots of paint on the stuff I paint. If someone wants to craw under my stuff and look for runs, more power to them. Redoing this stuff in a few years is not something I want to do.

If you really feel the need to prime the metal, Rustoleum makes a spray can product they call 2x. It is a mix of primer and paint. Make sure that stuff is shook up really well, and be sure the can is not below 50 degrees, or over 70 degrees. It does get into the few places you can't reach with a brush, but really, I get the brushes into most places. If you use the Rustoleum 2X paint, buy several cans, it goes away pretty fast. A single coat on the smaller truck frame could take 6 cans. You really need to do at least 2 coats of the 2x spray, 3 coats would be better. Or you can do one coat of the 2x spray, for those hard to get at with a brush areas, then follow that with two coats of the brush on Rustoleum. Be sure you follow the directions for the recoat time.

Pictures!
Pic 1, The white paint was some kind of rust prevention paint the previous owner put on the easy to reach parts of the frame. He painted right over the top of dirt daubers and rust. You can see the rust coming through the rust prevention paint. See how rusty the insides of the frame rails were? Any area not covered with the white paint looked the same. I would ***ume the metal under the paint probably looked about the same, since he painted the white right over dirt. By the time I was done with the air chisel, the sanding, and the metal prep, the frame was nearly rust free bare metal. The Rustoleum enamel was brushed on right out of the cup that was filled right out of the can. Nothing was added to that paint.
Pic 2, A closer look at the front of the frame. Notice in both pictures, the guy never painted anything inside of the frame, nor did he paint anything on the bottom of the frame. His paint job stopped at the lower curve of the side rails. I ended up sanding and air chiseling all of the white paint off. I don't have any pictures of the cleaned up frame.
Pic 3, Here is what the frame looked like after the cleaning and the 2nd coat of paint. I want to point out that there was still more welding to be done on the frame, the purpose at that point was to cover the areas that would be very hard to do once the body and the drive train was put on the frame. Notice the nearly everything inside of the frame and under the frame was also painted. You will also see that I was not concerned about painting the rear springs nor the rear axle, at that point. The two coats of what you see painted black took nearly the entire quart.
Pic 4, With the motor and trans bolted to the frame, most of the area under the motor was not accessible to paint, once the motor was bolted into place. You can also plainly see that the inside of the frame at the front corners was not painted inside at this point, several more pieces were going to be added soon afterwards and any paint inside the frame there would have burned away. After all the welding was done, any touch ups to the frame was done with two coats of the 2x Rustoleum spray cans, applied several days apart. Gene

 

Yeah i read somewhere else that thinning Rust-Oleum out of a can is only recommended for spraying not brushing. I may or may not add a hardener, if i do i will add about half of the recommended amount.

So the Rust-Oleum 2x is a primer/paint? Sounds like what i may use. I do plan to get the scale rust stuff Off, i would say it would stick better to bare clean metal, with very little surface rust. I would say it would take a day just to properly prepare it, and places i can't get to with a pressure washer at car wash, i had better lay on back amd take a green scotch brite pad and clean the dirt and debris with a degreaer/cleaner. Can the 2x be painted directly over with Rust-Oleum enamel without roughing/sanding. It will probably take 10-12 cans for a long wheel base 2500. I do have another question, do you recommend that i paint the gas to tank and the underside of the bed? Figured yes on the underside of the bed, because it will get over spray anyways, even though there's zero rust there. IDK about the gas tank??

 

I wouldn't even consider trying to sand any Rustoleum paint that is newer the 2-3 years old! It will gum up the sand paper in less then a minute! You can use Rustoleum 2x spray cans over enamel Rustoleum, or you can use the enamel over top of the 2x spray cans.

As far as painting the under side of the truck bed, if you can get it clean, and scuffed up a bit so the paint has something to "grab" onto, I would probably paint it. If you can't get it cleaned up and get the surface roughed up a bit, its pretty likely most of the paint (pretty much any brand) you put on the underside of the bed will flake off after a year or so.

As far as painting the gas tank, getting it clean is pretty important. Again, if you can't get it cleaned up, what ever you paint it with would likely flake off after a year. Painted gas tanks are pretty much a personal choice. The last 3-4 builds I've done have had plastic tanks in them, paint doesn't stick to plastic tanks.

 

The underside of the bed will probably flake off if care isn't taken as you said. I wander if i get some muradic acid (like used to etch concrete)and squirt the underside of the bed, that would turn it black. Would that be sufficient enough to help the paint stick to that smooth metal on on the underside of the bed? After that's done would i have to neutralize the metal on the underside of the truck bed and sand also? Or would a spritz of acid in spray bottle be sufficient and would the surface be prepared for the paint after it dries and turns black?

For the rest of the areas of the frame/ch***is, i will use a 36grit flap wheel and remove the scale prior to Rust-Oleum 2x.

 

Use phosphoric acid, not muratic. Neutralize with baking soda water, rinse well.

Stick with rustoleum quarts or gallons.

The rattle can is not the same paint, lot of regulations on spray paint.

 

Looks like it should not have to neutralize phosphoric acid with baking soda not if you give it time to reaction an dry - the the rust (iron oxide) has already acted as a base and should have neutralised the acid.

 

+1^^^ I agree after research.
One could use muradic acid (there will be splashing) but it would be hard not to get any acid on other metals by just applying it and if one applies it 50/50 there's still going to be fumes that will attack lungs and other metals, and paint. I work with this stuff a lot, i am a mason and use it to clean brickwork. I know how to use it safely. On brickwork you use it more like 70 water 30 acid.I have also used it with hydrogen peroxide to etch knife blades very successfully. Its probably more difficult to avoid paint on other metals when applying it to a vehicle.

I think i will use phosphoric acid instead. Muradic acid gives off fumes and will corrode other metals on the ch***is. I don't know if i will get to my project this summer or not because of work.
So can i use something like this? It supposed to have phosphoric acid, at like 35%. Do i use full strength? is the best way to apply with a brush? How long does it take to work? And when do i rinse off?
https://kleanstrip.com/cleaning-and-paint-prep/concrete-metal-prep/

Thanks,
Mike

 

I am a cheap *******. On my Ford, I used VHT Ch***is and Roll Cage black spray paint. I sanded and wire brushed the frame and ch***is parts, wiped them down with lacquer thinner and painted them right away. 7 years later it still looks good.

 

I've been using Rust-Oleum for several decades. It lasts for a very long time if applied correctly. I've used both spray cans and brushing with excellent results.
For rattle cans, I warm the spray can in hot water and shake the rattler every 5-10 minutes then return it to the hot water until the can remains warm in your hand after shaking. It flows on smoothly and looks like gl*** if you do it right.
Light even coats is always the key to spraying, whether out of a rattle can or spray gun. If using a spray gun, acetone works. I thin it to 22 seconds in a #2 Zahn cup.
Brushing, (though tedious), is a good way to get paint forced into those nooks & crannies on frames, but brush marks may remain. (Brush type, be it foam, nylon or hair is the user's choice. I prefer China Hair brushes) As stated above, pour some paint into a smaller container to dip the brush into and put the lid back on 'til you need more.
I have thinned Rust-Oleum (R.O.) with mineral spirits and brushed it on as it's own primer. It gets into those aforementioned nooks & crannies quite well and seals the surface. Let it dry so to a slightly tacky state, then a coat of R.O. over that. (I've also just applied the R.O. to a clean surface without priming also with good results) A good washing and wire brushing is really all the prep you need to do because R.O. has always had a converter in it and grabs onto the light rust on a microscopic level.
I noticed that when R.O.'s original copyright, patent, whatever, expired was when all the "rust converters" emerged onto the market.
R.O. will last for a very long time and is very durable. It drys slowly which can be annoying if you're hyper, but the slow dry is part of what makes it work so well in the long run. (no pun) It's also real easy to touch up later down the road.

 

I've used plain old Rustoleum gloss black paint on every hotrod build I've done for myself, and others for decades. I use a combination of rollers, brushes, and even thin with acetone to spray it in hard to reach places.
My oldest build is 12 years old now, and did it body on back then, and the underside still looks as good as it did back then.
I use it inside the cars also to paint floors, inner doors, and even inner roof, just to protect and prep them for sound deadener.

 

If adding a hardener be sure to wear gloves and long sleeves, and a face mask is not a bad idea. Rustoleum cans say
can be thinned up to 15%, I have used it with Flowtrol and hardener, brushed on doors and been asked if it was sprayed. As stated by Jacksmith the brush quality will make a difference.

 

I use the same product, full strength, brush it on or put in a high quality spray bottle. Keeping it wet keeps it working. How long - depends on how deep the pits are and how much you cleaned prior to acid.

Neutralize with baking soda water, or almost all detergent soaps are basic on PH scale and will neutralize it.

 

Maybe... if you can find straight phosphoric acid... The stuff available at box stores is prep and etch "for concrete" it has other ingredients and I don't want that other **** under my paint.

If you want to use an acid product and go straight to paint, without cleaning it off - better buy it at the paint supplier

 

Use black POR 15, brush it on, it'll cover and seal in all the rust and look like a powder coated frame.

 

Yep, POR 15 is definitely good stuff... It's like Rust-Oleum on steroids! (and so is the price)

 

POR 15 comes out of the can thin so work fast, wear coveralls, gloves and safety gl***es. If you're working overhead and want to be really careful, wear a cap and grease your face with Vaseline. If POR 15 dries on your bare skin, it can take a couple of weeks for it to wear off. In the meantime, you're going to look like you had some really bad tattoos.

 

Here's another idea. We used "Hammerite Rust Cap" on this roadster ch***is. It's available at Tractor Supply Stores (and sometimes Home Depot) and it's for farm implements in the field. I liked the "Hammered Finish" and that you can brush it on. Plus it's easy to touch up, too.

 

I used paint from tractor supply, I did add thinner to brush it on the frame. I did not add hardener to the paint I brushed on the frame. While I did add hardener to the body panels when I sprayed them ... The Tractor supply paint I simply thinned so it would lay down good and I mixed it up in a wide mouth pickle jar .... This way I could use my $1 nylon brushes from the dollar store.
I honestly think it looked fine, I did not see brush marks in the paint .... it laid down fine & I put a few coats on it.

That was 2 years ago, I was happy with the frame with no hardener added to the paint "Brushed ON THE FRAME!" I did add hardener when I sprayed the body panels.

I still have a long ways to go, the paint has seen weather, it still looks fine 2 years later.

 

That's absolutely right. POR-15 is some nasty stuff but my god does it work. Slather it right over rust and it bonds like hell to the metal and never comes off. It's most effective over a little rust or metal with some tooth in it, so when I want to change the finish, I'll POR-15 it, then scuff the POR-15 and shoot it with ch***is black or something like that. The thing I love the most about the POR-15 is how impact resistant it is. It's great for ch***is and frame components because they get blasted with road debris, little rocks and pebbles, etc. and it never chips.

 

I did a frame off on my '55 Ford Courier wagon and power brushed the frame and front suspension before brushing POR 15 on using a good China bristle brush. While the frame was tacky, I fogged on a coat of Rusteolum primer. I waited a couple of days and followed up with two coats of Rustoleum Smoke Gray gloss. After pressing all new upper and lower stock A arm bushings, I must not have gotten one of the lowers pressed all the way in because it missed sliding into place by a blond hair. I used a long bar to lever the A arm in. It slipped out and peeled the color coat off but did not scratch the POR 15. Now, that's tough stuff.

 

Works for me !! Tough as nails ..

 

S

So you have used the kleanstrip phosphoric acid full strength with good results?

What do you mean by keeping it wet keeps it working? You mean reapply before the previous coat dries?

 

Yes, klean Strip, full strength on wire wheeled frame. Keeping it wet - reapplying, keeps the acid working. I used a quality spray bottle to apply klean Strip.
I flushed the acid off with baking soda water with a few drops of dish soap, in a spray bottle, soft bristle brush, to neutralize and clean the surface.
Flushed with water, in a spray bottle
Blew off with air.

Painted the underside of the bed with rustoleum rusty metal primer and rustoleum red mixed 50/50. Painted the frame with black epoxy that was old and laying around the shop.
Roller and brush.

 

I like your avatar. Clever coop door. Or perhaps, that chicken is being honored as the a$$hole of the month.