scrappie

What is you guys opinion on the process of painting freshly media blasted pieces like frame and front end components? My thoughts:

Media blast
Self etching primer followed by
leveling any pitting with filler (sand)
epoxy primer
Paint (what kind)

I know powder coating is an option too, do you prime with anything before powder coat if I were to go with that?

thoughts appreciated.

bccan

After blasting I would D/A it with 220 or go 180 then 320, this will give you a like new finish on the steel + get any grit & dust off.

At this point if filling pits I would epoxy prime the frame to prevent corrosion then fill,sand,prime,block any "bodywork" done. Seal & paint, always everything quality, catalyzed product if that fits your wants & budget.

If going straight to paint (no bodywork) after sanding you could spray an epoxy product and the paint over it. This is possible in RM/Diamont/Glasurit (Poluroxy) that we use. Not sure about other mfgs.

If doing POR type product I would probably not sand frame to clean steel. At most maybe wire brush & paint it but check instructions from mfg.

scrappie

Thx, the thing that concerns me most would be chips and what would be the most protective coating. Powder coat comes to mind for that but leaning more towards a factory look. What do you think about self etching primer? Is there any benefit to using that? I would think that would be good on bare metal? Epoxy primer would be a hard coating under the paint I would think to protect against chips and corrosion? Is there epoxy primer that is black or can you tint it? Is there an epoxy paint for final coat or just a single stage top coat of some sort.
I may be over thinking it?

rpinnt

I think you may be over thinking it. It depends on what you envision for an end result: SEMA show car or daily driver or something in between? I went with powder coating on my frame, core support, etc. The main reason I went with powder was the cost: It was only $255. Granted the blasting was free (dad is a pro blaster) but I could not have bought the primers and paint for that let alone have someone spray it.

scrappie

That does look nice.

oddball

That's a steal on powder coating! Estimates around DFW were more like $500.

For my daily, I just washed it down after blast, etched, then POR15 Chassis. No need to prime or anything.

Body work on the frame is, IMO, completely pointless unless it's a show-only car. It *will* get road rash, grime, jackstand marks, etc. A thick glossy black coating - POR15, powder, or a chassis paint like from Eastwood - will make it look pretty and be durable.

My442

• Wash/Degrease
• Sandblast
• Pre Paint solvent
• DP90 primer
• Top Coat with a good semi gloss gloss black

The Eastwood Extreme Chassis Paint and primer work really well.

My442

• Wash/Degrease
• Sandblast
• Pre Paint solvent
• DP90 primer
• Top Coat with a good semi gloss gloss black

The Eastwood Extreme Chassis Paint and primer also works really well.

scrappie

Thx P
Is the DP90 a black epoxy primer? If not can it be tinted?

Thx oddball, My concern is durability and what it looks like if top coat is chipped off.

oddball

If you want durability, then POR is your best bet. You need a chisel to get that stuff off, and touch up for road rash is really easy.
It stays slick, so oil/grease/gunk cleans off easy too.

My big mistake is I used lots of engine degreaser while working on steering problems and spraying PS fluid all over the place 10 times or so. That crap left white stains all over everything.

My442

DP90 is a black etch primer. Bites really well on blasted metal.

It is very durable, but you need to apply it with a paint gun.

POR15 is junk, and if you do not prep the surface perfectly, it peels off.

If the car will be a driver, I suggest the Eastwood stuff. Easy touch ups if needed.

jensenracing77

It is a matter of what you intend for the car. I went powder coat because it was less money and if done right, you can't tell a difference when the car is together. With powder coat you will want nothing on it for primer. It is bare steal and then coated. If you have pitting, you have to use something like JB weld to fill them. Filling pitting is a royal pain in the butt if you go powder. If you use filler, it will burn off when they bake the powder coat.

jensenracing77

Here are some pictures of powder coat. You can still see the machine die marks in the frame and stampings in the control arms. I have no problem with paint or powder coat but I have seen some very poor quality powder coat jobs.

scrappie

That does look nice, I will have to see what kind of pitting I have after it is media blasted and what options I have in my area?
I'm thinking GM just painted raw steel with an enamel? so whatever I do will be an upgrade.

My442

As one of the few folks on here who actually worked on the line at a GM assembly plant (Framingham) in 1972, I can tell you definitively that:

1. GM did not use any primer on frames, suspension parts, brackets or hardware. All raw steel.

2. Frames were assembled upside down, and lightly "dusted" with a cheap black paint that came in 55 gallon drums. The amount of "dusting" was up to the discretion of the line worker. Just enough to stop flash rust before the car was sold.

3. GM was really cheap on adding anything that increased cost. If you look at pedal assemblies or parking brake assembles, note that the area you could not see was intenionally left bare.

4. Brackets and other parts were dipped in a vat of water with about 1" of black paint floating on top. The parts were hung up to dry, hence all of the drips and imperfections.

So if you want to duplicate the factory,do the following: Rush through the work, use as little materials as possible, and don't give a rats' *** about coverage and quality.

I laugh when people restore these cars in the same manner as Rolls Royce built them. That is why a GM car cost 1/20th of a Rolls Royce.

scrappie

Good stuff, amazing how some cars survive all these years

My442

The mediocre rust prevention was one of the main causes of the demise of 1960's cars. The road salt and moisture ate them up in 5-8 years, especially in the rust belt areas.

Cars today are MUCH better resisting corrosion, due to better materials and coatings.

The survival rate is probably less than 10%.

scrappie

I remember growing up and observing cars and there seemed to be a lot of rusty cars driving and more all around sh%t boxes back then. Hell my mom used to drive me around in a rusted impala. My first car was a 1972 cutlass supreme which I inherited from my mom and saved from junk yard (rusty) and it is what started this whole thing for me. I guess we have made some strides?

My442

A good friend of mine is an expert in metallurgy, and told me that iron and steel want to turn back into dirt.

Moisture, salt, pollution just help speed up that process.

I grew up in the 1950's and 1960's, and the amount of rusty cars was huge.

In New England, most cars were rusted out in 5-7 years if they were winter driven.

briane

My understanding is that etch primers contain an amount of acid, probably phosphoric, to assist in activating the surface thereby promoting paint adhesion. I generally treat bare, clean looking steel, with a Metal Prep that is phosphoric acid followed by GalvaPrep which converts the surface to something like zinc or iron phosphate, and then prime. These products can be obtained at automotive paint suppliers. Manufacturers of steel products typically follow such a process on their paint lines.

As a chemist explained to me, the surface of blasted steel is very active--with any dampness it can flash rust very easy. And like the acid activated surface it is ideal for painting. For freshly blasted clean steel follow My442's suggestion, wipe of the dust with a solvent that evaporates quickly without leaving a residue and apply an epoxy primer. The Dupont DP90 black primer worked great for me (can you still buy it?). Then do any pit filling. You should top coat epoxies as they're generally not UV stable.