Powder Coat a frame?

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well, to me, it depends on your definition of "slight chipping".
if you are getting thumb nails size chips off then there is a good chance the whole job was questionable.
if you are getting the odd 2H pencil eraser size then a fine sanding and touch up paint with quality etching primer and paint the spot.
if the body isn't on the frame yet then take a ball peen hammer and in places that you won't see hit the frame real hard. the PC should dull and you might even go down to bare steel but at no time should it "chip" off. i do that with every frame that i get back as well as a couple of the pieces as long as it is going to be hidden.
last thing i want is to assemble a project and end up with chipping or flaking.
if you are getting thumb nail size chips or if the PC chips of flakes when you hit it with a hammer then best to get the frame blasted properly and re-PC it again. probably not what you want to hear ...
 
Here is a picture of the area in question... It is the rear cross member. I will pull it out of the garage this weekend and fully inspect the entire frame.
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proper PC should not chip like that.
can you pick any loose stuff with your finger nail?
if you hit it with a hammer does it come off?
i wish i knew how to post vids and i would show you the test i do.
cheers
 
that should never have chipped.......my local powder preheats all projects. for the chip, hit it with a can of paint and let it be a lesson learned. for the OP, what have you decided?
 
might be best to find out why there was no bond. if a contaminate is there then the paint won't stick for long either.
at least sand the exposed area and wipe with cleaner before applying the paint.
burnttoastburgos said:
that should never have chipped.......my local powder preheats all projects. for the chip, hit it with a can of paint and let it be a lesson learned. for the OP, what have you decided?
Click to expand...
 
there are polyurethane paints and polyurethane powders. There are epoxy paints and epoxy powders and there are polyester powders and paints. The point is they are all the same structure just applied differently.
Paints are suspended in an aromatic solvent or in some cases water whereas powder is just the solids in a very fine powder form. The advantages of powder go almost all to the applicator. Parts can be sprayed faster, cured faster and shipped faster. Permits for getting powder booths are easier in many states because there are no hazardous solvents involved. Paint requires more skill and practice to apply.
Rules are the are the same for paint and powder . Cleaned prepped surface and a proper cure. Costs in both cases are highest for the prep. Spraying the paint or powder is the easiest part. The prep is the
the time consuming part but also the part that will determine the longevity of the finish. It takes 15 minutes to spray powder to a frame but 3 hours or more to sandblast , wash and hang it
 
My paint guy at Car Quest talked me into a can of chassis black from DuPont, I guess this is what all the local body shops are using now. He recommended a good self etching primer for a base. A gallon of paint runs a total of $49.00 as compared to the POR 15 at 150 ish.
I know that everyone raves of the POR I thought I'd do a test. Seeing how both paints don't use a activator I had him put some in rattle cans. He cringed at putting POR in a spray can saying that It wouldn't work because its too thick. Guess what, works fine. I sprayed several parts to see the difference without any problems with either of them. All parts are blasted.

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Chassis black

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Chassis black primed and 2 coats of paint

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POR 15 from a rattle can.
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I'm assuming you're taking the parts down to clean,bare metal? If so, POR is of no use to you. Use an epoxy paint/primer combo and never look back.

Also, you need to find a new paint guy if yours recommended topcoating directly over self etch primer.
 
Yes to bare metal.. But I was told to let it sit for a week or so before painting g with the POR. Or to acid it.
As for the chassis black, it does say to use etching primer on bare metal.
Why? What will happen with the self etch. and painting over it??
I'm not a body guy so fill me in please before I go too far.
 
i was told to make sure the bare steel had a good quality primer before coating with POS15.
 
I think powder coating a frame is a bad idea on anything besides the "muscle" cars mentioned earlier. That kind of vehicle, I am sure it is fine if prepped and applied right.

I have had a lot PC done, just not a frame. Here is my example of why I don't like it. On my 04 Taco I had all my bar work and wheels PC with silver vein. The Taco has stock mud flaps on the front. After 25,000 miles the tires had thrown so many rocks and such up onto the front edge of the sliders there was literally a palm sized area that the PC was gone. It looked like it had been sand blasted here with a very coarse medium. Rust was forming pretty bad on the bare steel. I know people say why PC the sliders. Thing is they were mostly used as side steps not sliders, in fact I didn't offroad the truck where the sliders would actually be used. On other trucks and the Taco I have had wheels done. If I stay out of the sand and gravel, it is fine on the wheels. Stay out meaning don't bury the truck in that stuff. Bumpers and other bar work, no problems at all with PC but I did notice it wearing thin on the rear bumper where the tire carrier was two surfaces sliding together.

A frame is going to be subjected to gravel, sand and other stuff even if just driven on pavement. At least around here where I live there is always some sand/gravel on the road, ie shoulders on HWY, parking lots, ect. A frame is going to take hits from this stuff and is going to chip eventually. Once that happens, as others mention it is at the least a pita to touch up. As far as an FJ40 I see two spots that would be my main concern with PC. Behind the front wheels on the "outrigger" and behind the rear wheels on the rear crossmember/bumper. Both these areas are going to get hit by rocks, sand and the like fairly often.

Now PC items that can easily be removed and blasted (actually burn it off) and re-powder coat seems fine to me. That is not a frame though. I am actually in favor of this, ya know bumpers, wheels and things like this.

I am a big fan of Rust Bullet this last year or so. I have used it a few times now. It is a touch tricky to apply right since it does gas off a lot and if done wrong that will create tiny bubbles. However, I have had some overspill when working with it. On some wood I had a big puddle of the stuff. After a week or so of it drying I beat on it with a 3lb sledge. I was unable to chip it. After that I was sold on RB. I have applied this stuff to the inside of a fully boxed frame. Not an easy or fun task but doable. I sprayed a ton into the frame and rotated it while the paint was wet. Also lowering one end to allow the paint to "flow" into all areas. I also applied it by hand to all the seams on the frame rails and behind brackets and so forth. I then sanded it all back. It is supposed to "encapsulate" the rust. I was very happy with the results. My next frame I am planning to do the same way but top coat the outside of it with the RB "Blackshell".

Last frame I did we simply painted it with DuPoint Imron after several coats of sealer. I have applied this stuff with a brush to touch up and I got to say it goes down easy with a brush and self levels. Pretty hard to see any touch ups. Here is what it looked like sprayed on....

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Dipping with paint I think is the best way to go on a frame but from what I have seen not cheap. Galvanizing is probably the best way to deal with the inside of a boxed frame.

My 2 cents

:cheers:
 
so, you actually think that paint will stand up to rocks better than PC?
i disagree completely.
 
crushers said:
so, you actually think that paint will stand up to rocks better than PC?
i disagree completely.
Click to expand...

I don't think the argument should revolve around what will "stand up better to rocks" since both will yeild to scraping the frame over boulders and large rocks. The key factor is that paint is easier to spot repair and keep rust from creeping under previously coated areas. I PC'd my roll cage and now wish I had paited it since it has tree scrapes all over it that I can't just sand and paint over.
 
who told you that you can't sand the scratch and paint over it? or is this a personal assumption?

once again, properly applied PC does resist stone chips and scratches better than regular paint but anything, including glav, can get gouged to the point of rust. galv is better for resisting rust in the gouges.

i keep hearing that the PC allows rust to bleed under the paint (think cancer) but properly applied PC WILL NOT allow this to happen. it is bonded to the metal.
 
if you want to paint or PC over galv then either withing 48 hours or after a year is the easiest.
from 48 hours till fully cured the galv can be a bugger to get paint or PC to adhere without flaking in the future
once again, do your research.
we had a galv frame that i wanted to PC. the previous individual had painted over the galv without doing any research (obviously) and the paint was coming off by running you hand down the frame or picking with your finger nail.
the frame had been sitting like this for 4+ years, light sand blasting and off to the PC. now you can hit the frame with a hammer and no issues. the frame looks very good and should out last the next 2 owners of the truck ... or more.
the life expectancy of a galv + PC frame is 100+ years ... or so they claim.
 
We've powder coated several things with no issues over time thus far. I have to agree with statements like Crushers that if its done right it's awesome stuff. Our powder coater is really particular about blasting first, then pre-heating the item to burn off anything the blasting didn't remove and then powder coat and bake. I'm personally battling this decision right now for our expo trailer I'm finishing up (paint or pc). I'm meeting soon with a new pc place with a larger oven to get there thoughts.

If this was being done over bare metal w/light surface rust and it was being painted what would be the best process?


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-Daniel Kent
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