Painting Rear Galvanized Crossmember

Z.G

Well-known member
Looking for info from anyone that's painted the rear face of a galvanized chassis after the vehicle has been assembled. Any tips? The galvy shine looks odd with the white truck.
 

WreckITFrank

Well-known member
My buddy is a welder and paints galvy daily. They do minimal prep, etch prime and good topcoat. He's partial to SEM. I read white vinegar for prep, then etch prime and paint. Never did a cross member, but he said the galvy beams hold up just fine in the weather.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I painted mine. I wanted the galvanized look for the Series, the more updated look for the Defender. I just lightly sanded it and cleaned it with brake parts cleaner, then used some satin or semigloss Duplicolor. I believe I brushed it on, but can’t remember. It still looks good after five years or so, but there are some flakes that will need to be addressed. But this was expected, not a big deal. I’m leaving it for now so I can show potential buyers that it really is galvanized.

Also, my front bumper from RN is galvanized and then powder coated
 

Napalm00

Technical Excellence Contributor
SEM makes a galvanizing specific prep fluid, while I've never used it it's some kind of etchant like described above
 

1of40

Well-known member
I agree the shiny galvy is ugly. Im not going to paint mine but hope that vinegar washes will bring some patina to the rear cross face.
 

erover82

Well-known member
There are many options depending on the paint system used. Are you doing this yourself or having a shop do it? Any competent shop should be able to coat galvanized metal properly with your desired finish. The factory chassis coating is an industrial catalyzed baking alkyd enamel typical of auto manufacturing at the time. A shop applied satin or semi-gloss urethane will provide a much more durable finish.
 
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Z.G

Well-known member
PPG DX579 metal cleaner, then DX520 Metal conditioner. Google them up for proper application and usage.

I used them when I painted both side frames on my 110. Going on 4 years now and the paint is still perfect.


Excellent, just ordered those locally. What'd you use for paint after prepping with that?


I agree the shiny galvy is ugly. Im not going to paint mine but hope that vinegar washes will bring some patina to the rear cross face.
Just looks odd with white, but I agree it looks better once it dulls down

There are many options depending on the paint system used. Are you doing this yourself or having a shop do it? Any competent shop should be able to coat galvanized metal properly with your desired finish.
Im going to do it here since it's sort of an odd job. If I screw it up, I'll have a shop do it
 

erover82

Well-known member
Im going to do it here since it's sort of an odd job. If I screw it up, I'll have a shop do it
There are greatly varying levels of DIY in painting. Are you looking for the best job you can get from a can, or from a gun? Do you have access to a spray booth, equipment, PPE, spray gun experience? Isocyanate and VOC exposure is no joke.
 

Z.G

Well-known member
Not trying to go crazy with it, but I do have access to the equipment and PPE. A high quality can would definitely suffice for my needs
 

erover82

Well-known member
The majority of spray paints and primers are alkyd based which will fail when applied to galvanized surfaces. For best results from a can I'd start with a 2k epoxy primer and finish with a 2k urethane, such as SprayMax. PPE required.

 

donb

Well-known member
I am going to do the same with my galvanized chassis this winter. I have been planning to use Steel-It paint as I thought I read it could be sprayed right over galvanized metal but I need to confirm that.
 

erover82

Well-known member
I am going to do the same with my galvanized chassis this winter. I have been planning to use Steel-It paint as I thought I read it could be sprayed right over galvanized metal but I need to confirm that.
Their polyurethane system prescribes an alkyd primer which will chemically react with galvanizing and peel. Their two epoxy systems, like nearly all etching epoxies, are compatible with galvanizing. All their systems involve 2-3 coats total of primer and topcoat.

No matter which product you choose it's important to view paint as a carefully engineered system and follow the directions as accurately as possible. Some paint systems are incompatible with, or conversely, may require certain strategies of surface prep.


Another note on the 2k SprayMax products.. Being an internally-mixed single-use product, it's best to have every piece you'd like to finish prepped and ready to paint. If you have other brackets and parts that need painted, do them all at once. Once the can is mixed, the pot-life countdown begins.
 
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WreckITFrank

Well-known member
Another note on the 2k SprayMax products.. Being an internally-mixed single-use product, it's best to have every piece you'd like to finish prepped and ready to paint. If you have other brackets and parts that need painted, do them all at one. Once the can is mixed, the pot-life countdown begins.
I had about a 10 hour window in 70 degree weather with the epoxy primer. Went on well, nice coats. I even botched a top coat and removed with paint prep and another solvent and the primer held up extremely well. Great stuff.
 

O2batsea

Well-known member
If the galvy is still fresh and shiny then you can get away with a solvent wipe and then the epoxy primer followed by top coat. If it has any white blush, you will have to (stainless steel) wire brush it to shiny metal then the solvent wipe etc.
 
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