Powdercoat and rust...
 

While watching Tv (Musclecar on Power Block) they were powdercoating a frame. It had A LOT of surface rust on it.

The powdercoating place shot right over it and baked it. Is that ok to do?

I had assumed that like paint you would want a CLEAN surface before applying any kind of coating.

Does powdercoating seal it up and keep the rust from spreading or are they going to have troubles down the road with the Impala frame?

I was thinking the exact same thing when I watched the episode this AM!!!

The only thing I could think of was that some of the cleaning solutions they used killed the surface rust and left a "rust protection" coating that gave it that "gold/brown" haze and what we were seeing wasnt actually rust.

I would think if it was rust, there would be issues. I was suprised that they didnt media blast the frame again.

i dont know but i cannot imagine that that would be the best way to do that...... im kinda like you, i would have thought the prep would be close to that of prepping for paint....who knows...

Ned, did you notice the shot of them hooking up the ground lead? There was a TON of rust right there and it looked like it was more than just surface crud from that day.

I don't know much about the whole process but it just didn't look right to me from a common sense point.

I saw that too! Was it funny to you that they were bragging about they're powder coating system after showing that scene? Terrible promotion IMO. They wouldn't get my business.

Not to mention, the finished product looked like crud because of the pitting.

Paint or Powder coating over rust is a NO NO! it will always continue to rust It has to be neutralized in some form The easiest is POR 15 that seals oxygen out to stop the rust (even that uses a neutralizer) or a converter that combines with the rust form a new rust resistant base :thumbsup:

The guys that powdercoated my last frame let me stay throughout the whole process. I asked the same question about the surface rust after they pressure washed it, and he said that was normal.

I would say no rust anywhere. I had a bumper done years ago and it bubbled up in one area, after peeling it back, it was surface rust that caused it to bubble.

How else would you get a frame completely clean without soaking it in a cleaning solution, pressure washing, then baking it. Without the surface rust?

once the area is cleaned in what ever fashion you want you need to protect the surface with a zinc phosphate coating, there are other coatings out there also that do the same thing and many top shops can recommend what they prefer to use, just remember any rust is rust, many try to justify it by saying is only surface rust, the only way it will stop it is not allowing the rust to oxidize (oxygenate) by sealing the rust completely or removing completely, Paint, chrome, vinyl tops, body wraps, all let oxygen in :faint:

No they did not powdercoat over the rust. I know the shop that did it. They just editied for TV. It was sand blasted the preasure washed baked then coated baked again.

powder coating
 

I wanted to scream !!! WE sandblast with 120 grit shot, then do a 3 stage phophate wash with a anti/rust sealer . If needed we then epoxy powdercoat prime. Then we would apply the powder topcoat.

I was embarrassed by the way they powdercoated that Impala frame. It is not the way we do it. www.extremepowdercoating.net new wedsite launches Friday. There will be many pictures of the correct way of powdercoating.

Thanks for clearing that up!:thumbsup:

It's time to find a new powdercoater, if powdercoating is done right, it will not chip easy at all, it's some of the toughest finishes

I agree with Stephan --- Powder coating is tough stuff.... and many times you can bang it with a hammer - and dent the metal and barely even scuff the coating... if it's chipping -- then something isn't right.

as I said before, find another powdercoater who doesn't cut corners,2 most important steps are blasting and etching powdercoat primer, I've had countless parts done by a local powdercoating facility ,from suspension,3 piece and cast wheels to racks, bumpers,stainless trim,exhaust tips and this stuff does not come off ,I've even tried razor blade,scraping it with scraper doesn't do anything but scratch the surface, so it's obvious,whoever did your rear end skipped a few important steps,

and I forgot to add, it's alot cheaper than paint, I actually own paint/body shop and I prefer powdercoating over paint,just for example, they charge me $40 to do a full size truck bumper ,$20 a piece for 22" center of 3-piece wheels, and as comparison, I'd charge no less than $200 to paint a bumper and $75 a piece for 22" wheel center

powdercoating
 

If the powder is chipping that easy SOMETHING is wrong it is probably a pre-treatment chemical problem or the parts are not fully BAKED AND THE POWDER IS NOT CURED.

Read post #43

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