Paint over powder coated steel?

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DanMedeiros

DanMedeiros

10 Year
Joined
Jun 4, 2015
Threads
42
Messages
643
Location
Reno ,NV
Hi everyone,

Since I just painted my LX my old ARB bumper is looking pretty bad. It's starting to rust through the original powder coating. Can this be repainted or does it need to be sandblasted and re-powdercoated? I was planning on brushing off the loose rust, scuffing it, then panting with chassis saver. Then spray painting with a rustoleum rattle can.

Thoughts?
 
You can but the paint wont stick. Eventually it will peel off. Best bet is to sand blast, remove all the rust then prime and paint or re-powder coat.
#1 thing is to get rid of the rust. If you dont get rid of the rust 100% then its just gonna keep rusting.
 
Powder coating places will blast for you before re-coating. However you can sand the rust down yourself and hit it with a can and it will stick for some time.
 
The paint option sticks for a year or two. Get the rust and it will last longer with etching primer. I hit mine with rubbing compound and wax after the paint cures, blends in nicely.
 
I just redid my front bumper. Was painted originally but not sure it would matter. Sanded down as good as I could then did chasis black coating from Magnet paints and covered it with Monsta Liner (also Magnet Paints). Looks great and seems like it will hold up, already rubbed it on a log and just left a little scuff that came off when I washed it.
 
POR-15- kills rust and it can be touched up...it's super frickin tough!!! like, make sure you use plastic wrap when you put the lid back on the can or you'll rip the can trying to get it back off!!! and you can bang on it with a hammer and it won't chip kinda tough! and if you mar it or get more rust somewhere else you can just repaint it.....powder coat will need to be repowder coated.
 
It's making a mechanical bond, so as long as you prep it right, it will stick. I would use my HF spot sandblaster and get all of the loose and rusty metal down to bare steel and then I would treat those spots with the POR15 prep product and then POR15 after sanding with 60 or 80 grit on the whole bumper then treat with and then top coat with Rustoleum Professional Satin Black before the POR15 cures all the way. You can get a pretty good result that way. I do all of the used parts I buy and many of the ones that came with the truck using this method and everything is holding up well and by sticking with a standard paint brand and finish, you can black out all sorts of stuff on an 80 and it will look nicer than rusty baloney.
 
Last edited:
LandCruiserPhil said:
Krylon satin black is an excellent match for ARB powdercoat black
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I swear something changed recently with Krylon paint. It's super runny now and I stopped buying it. It didn't used to be that way. I am wondering if the EPA nabbed them or something? I have had good luck with the Rustoleum Professional Series in all of the colors I have tried though.
 
I think for the most part, rust on an arb bumper (or anything powder coated, painted, por 15, etc) means an adhesion failure under the coating at the metal and O2 getting through the coating, often due to uv degradation. Production coating jobs generally aren't as tough as a job shop can do with blasting, pretreatment wash, epoxy powder primer base, and super-durable powder topcoat.

The best fix is to blast off the coating and re-powder coat it. Done properly there isn't really anything more durable out there, not without other big drawbacks imho.

That said, you may be on a tighter budget than the $250-300 to have it done. In that case, since you aren't using a metallic paint, you can sand the bumper with as rough as 180 grit to prepare to paint. Areas cut through to bare should get an etching primer or epoxy primer. Epoxy is very tough but is worthless in uv exposure. Paint is dealers choice at this point. I like Phil's suggestion - simple and the right gloss. Do lots of thin coats and try to build some film. After a good drying time (a few days), wax is your best friend. This will form a new oxygen barrier to slow the deterioration of the metal/coating bond.

As a matter of fact, wax and paint sealant (like wizzards brand, or even 303 aerospace) are a great idea on newly powder coated parts, painted items, and plated items to help them last longer.
 
dogfishlake said:
I think for the most part, rust on an arb bumper (or anything powder coated, painted, por 15, etc) means an adhesion failure under the coating at the metal and O2 getting through the coating, often due to uv degradation. Production coating jobs generally aren't as tough as a job shop can do with blasting, pretreatment wash, epoxy powder primer base, and super-durable powder topcoat.

The best fix is to blast off the coating and re-powder coat it. Done properly there isn't really anything more durable out there, not without other big drawbacks imho.

That said, you may be on a tighter budget than the $250-300 to have it done. In that case, since you aren't using a metallic paint, you can sand the bumper with as rough as 180 grit to prepare to paint. Areas cut through to bare should get an etching primer or epoxy primer. Epoxy is very tough but is worthless in uv exposure. Paint is dealers choice at this point. I like Phil's suggestion - simple and the right gloss. Do lots of thin coats and try to build some film. After a good drying time (a few days), wax is your best friend. This will form a new oxygen barrier to slow the deterioration of the metal/coating bond.

As a matter of fact, wax and paint sealant (like wizzards brand, or even 303 aerospace) are a great idea on newly powder coated parts, painted items, and plated items to help them last longer.
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I could do this job for $11.
 
Red Merle said:
I swear something changed recently with Krylon paint. It's super runny now and I stopped buying it. It didn't used to be that way. I am wondering if the EPA nabbed them or something? I have had good luck with the Rustoleum Professional Series in all of the colors I have tried though.
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Yep, EPA changed the regs, affects all of the standard, over the counter spray bombs. I miss the old, re-coat anytime formula.
 
Red Merle said:
I could do this job for $11.
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Yep. If you do the labor yourself and take care of it (and an easy environment out of harsh salt-winters), you can do it cheap.
 
Tools R Us said:
Yep, EPA changed the regs, affects all of the standard, over the counter spray bombs. I miss the old, re-coat anytime formula.
Click to expand...

Pre 1978 had lots of good stuff in paint, not so good for health, but great paint. I remember my old boss always commenting on how the lead in laquer paint made it shine so nice. Not sure if that was entirely true but it definitely got worse after that time.

So the latest round of paint devolution is probably VOC reduction?
 
dogfishlake said:
Pre 1978 had lots of good stuff in paint, not so good for health, but great paint. I remember my old boss always commenting on how the lead in laquer paint made it shine so nice. Not sure if that was entirely true but it definitely got worse after that time.

So the latest round of paint devolution is probably VOC reduction?
Click to expand...


I figured something had happened. I wonder why the Rustoleum Professional Series still works well? They must have a different formula that wasn't as affected by the new regs.
 
This is probably the best post in regards to Por-15 there’ll ever be.....

Por15 is CRAZY tolerant of heat. Thanks mean, paint something that is metal, black. Put it in hot Arizona sun for a couple hours and go to pick it up. It will be VERY EASY to pick up. That means, NOT crazy hot. I stumbled onto this fact by accident.

Also, if you use it, put some plastic wrap under the lid when you close it so that you don’t destroy the can trying to get it opened later.
 
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