Powdercoat vs baked on enamel

[volaredon]

Used to be everyone it seems would claim their merchandise was finished in "baked on enamel" Now a days I think everyone powdercoats their stuff. (commercial bought merchandise)
I know a guy that works for VALSPAR, and the plant he works in makes baked on enamel different paints, depending on application, all having different baking temps. Powdercoat is baked at 450*F some of the baked on enamel is 350, some is baked at 550*with some in between.
so which is more durable? I have heard there is no "chemical bond" on PC where there is on paint. meaning that makes PC less durable and more prone to chipping off.
Is there any truth to this? I have seen alot of stuff thats been PC'd and it seems indestructible.

 

[TheGrooveking]

Good question, I too was wondering about this. In the mid 80's I toured a few manufacturing companies one of which was Pelouze scales and can remember being in the oven room when the opened up these large oven doors and rolled out carts with hundreds of scales. It reeled of an epoxy kind of smell which caused me to ask if they used an epoxy and the manager giving the tour said "no it is an enamel". It would be great if an expert on this would educate us on this matter.

TheGrooveking

 

[volaredon]

I have had a couple sets of steel wheels powdercoated years ago and they held up fine (used them on my Jeep) but having been a front end alignment guy, I remember particularly on the Ford trucks of the early-mid 90s which are known to have issues with shackles and front spring brackets rusting out, they had a coating of some kind on them; and this coating would peel in strips, and be rusty/bubbly underneath. This coating was meant to protect the metal. but it seemed to "speed up" the deterioration instead. I am wondering if this was powdercoat; if so, what I have heard about "no chemical bond" may be true. They rotted out faster than the older versions of these trucks which had no coating at all, just bare steel. I always wondered what this "paint" was, that they had used on them.
At least bare steel is exposed, so it can dry; you get moisture under a coating, it don't dry out as fast and accelerates rusting
another option; it's possible they didnt prep the surface right, each step added to such a major production line adds cost.
At present, I am redoing a 2 post Weaver lift before I put it up. I was just gonna put it up, in as-bought condition, figuring that it wouldn't stay that "pretty" for long anyway, and "pretty" don't make a lift work any better.
but being that my son happens to be the "sandblaster/powdercoat guy" at his job, he convinced me to let him take it to work and powdercoat it, before I put it up in my garage...
my concern is mostly in the base plate of the columns, and the floor plate that goes between the columns, where it can't be seen>> but will be in constant contact with concrete on the bottom. IDK what finish Weaver would have been using in 1986, but even the top side of the base plate, and a few inches up the column is peeled and surface rusted; understandable for a 27 yo piece of industrial machinery; but the coating (paint?) is fine, held up good, beyond that lower most few inches off the ground. (the floor plate has been brush painted at least once though, the columns haven't been).
I don't want what is in contact with the ground to rot out from beneath.

it isn't peeling in the same way those Ford truck spring brackets did, so I think it was some kind of "paint" and not a powdercoat type substance used originally on this lift. it "flakes" off, like a "paint" would, when scraped with a razor blade.. not coming off in long strips like those suspension brackets would
Yes we are sandblasting and coating the entire column not just the flaky/ peely parts...
my neighbor that works at Valspar suggested that if I wanted, he could get me some baked on enamel that we could paint the lift with rather than PC it, (not "free" but cheaper than Rustoleum bought at retail, so he says) and being my son is currently doing PC, we obviously have access to an oven to do the baking, if we went that route.. which would hold up better?

consider the environment, (home garage not a production shop-- rack use probably 2-3 times a week, not multiple times a day like a production shop) sweating concrete, no airflow between the concrete and bottom of the column bases and floorplate) auto fluids that could be spilled on the lift at any time (brake fluid, oil, gas, antifreeze) tools being dropped, the lift arms being kicked and possibly run into by my riding mower, and such ("likeliness to chip" factor), the lift pads being scraped against a car's lift points and such.
I will have dry heat in before next winter, some of my moisture issue is the kerosene "torpedo" heater I have been using out there to date/by next winter I will have my hanging NG Modine heater connected and working.
I know every piece of equip and environment is different...

in this case the cost will be less than "retail" which ever way I go, so cost isn't as much a factor as it would/could be...

 

[volaredon]

this thread is getting buried; I was hoping someone might pop in and talk about differences pros and cons of each refinishing option. we could add in conventional paint (automotive grade and/or industrial)
I have some lower edges on my Matco 2 bay chest starting to peel and surface rust and I may wind up having to take the drawers out and refinish the cabinet itself, in the not too distant future, this was very expensive when I bought it back in 99 and the same box costs more now a days than then; the box is in very good cond otherwise.... so i'd rather maintain and preserve it.

I know the best option sometimes has to do with whats available, time available, and cost.... alot of us that use our garages as workshops do so in restoring/rebuilding "something" cars, tractors, antiques, or whatever. and I think there are probably others out there wondering "Difference between"? and "what's the better way to refinish _____"? Durability under _______condition,etc.

 

[dirtydogintex]

A friend has a sheet metal shop where they primarily use a 2 part SW paint (Polane or more $$$$).

Years ago he claimed paint tended to flow into cracks/crevices whereas PC 'bridged' instead.
Don't know if thing's have changed over the years....

 

[volaredon]

A friend has a sheet metal shop where they primarily use a 2 part SW paint (Polane or more $$$$).

Years ago he claimed paint tended to flow into cracks/crevices whereas PC 'bridged' instead.
Don't know if thing's have changed over the years....

That's something I never thought of either... Id rather have it flow into seams and such on that toolbox.

 

[Spudland_Dave]

IMO Depends on what your coating and who's doing it....Big difference between powder. For example...I had modified a Fisher Plow for my tractor...the factory powder was peeling in sheets. Had it powdercoated locally by a high end powder shop and the finish on blade is tougher then nails...been since the Winter of 08/09 and not a chip or any complaints...same goes for the multitude of items I've had coated there (or my buddy). So when people say powder is junk I can only say it all boils down to how it was done.

Biggest drawback to powder is the inability to use any body fillers or such..if your doing dent repair or anything like that, powder is out.

 

[Rockuf8]

Powder is only as good as the surface preparation. Most items that are powdercoated in bulk that you buy off the shelf are just sprayed onto a non blasted, non prepped substrate. Which is why when stripping a previously pcoated part and redoing it usually yields better results if done correctly.

I've wondered the same thing though regarding peeling. Once powder wears and starts to peel it coves off in sheets where paint peels only when rust is an issue. I powdercoated a set if aluminum wheels that only last 1 year, rust wasn't the issue, poor prep, overcuring etc might've been the issue there.

 

[volaredon]

Powder is only as good as the surface preparation. Most items that are powdercoated in bulk that you buy off the shelf are just sprayed onto a non blasted, non prepped substrate. Which is why when stripping a previously pcoated part and redoing it usually yields better results if done correctly.

I've wondered the same thing though regarding peeling. Once powder wears and starts to peel it coves off in sheets where paint peels only when rust is an issue. I powdercoated a set if aluminum wheels that only last 1 year, rust wasn't the issue, poor prep, overcuring etc might've been the issue there.

I didn't think it could be "over cured" but then again I have never done the process myself either.
I can see where parts done in quantity on an assembly line wouldnt be blasted etc like the Ford truck parts I referenced above... probably stamped and then sent for PC with mill scale, oils etc still there certianly I doubt they blast anything, in such a setting.

so any comments on various paints, whether bake on, spray on, hardener added or not, in comparison to having something PC'd?

 

[bowmard]

<<< but having been a front end alignment guy, I remember particularly on the Ford trucks of the early-mid 90s which are known to have issues with shackles and front spring brackets rusting out, >>>

You bet, that was not one of Ford's better ideas. I had a '91 F100 for many years but I had to sell it when the frame started to bubble up and disappear.

 

[Spudland_Dave]

Powder is only as good as the surface preparation. Most items that are powdercoated in bulk that you buy off the shelf are just sprayed onto a non blasted, non prepped substrate. Which is why when stripping a previously pcoated part and redoing it usually yields better results if done correctly.

I've wondered the same thing though regarding peeling. Once powder wears and starts to peel it coves off in sheets where paint peels only when rust is an issue. I powdercoated a set if aluminum wheels that only last 1 year, rust wasn't the issue, poor prep, overcuring etc might've been the issue there.

Bingo... AND I can attest that a properly Blasted & Prepped substrate does NOT make for Powder Coat Peeling. I have a couple small scratches at the lower edge of my blade (it is a blade afterall) and no problem whatsoever with peeling.
One of my buddies had his OEM GMC Aluminum rims powdercoated "Aluminum Silver" IMO Looks better then factory and 2 years later, they look just as good as the day he had em done.

PROPERLY done is the key...people think its as easy as using the HF or Eastwood kit when your wife is gone so you can use the oven.

 

[Rockuf8]

Applying powder too thick also makes for brittle powdercoat. Bottom line us some powdercoaters are lazy and cut corners. Anyone that thinks you can powdercoat clean new metal without putting it through some type if media blasting is dilusional. It won't hold up too long.

 

[theoldwizard1]

Powder is several times thicker than paint. Typically more durable (assuming proper preparation).

Paint will give a more glossy finish. Powder will always have a bit of waviness to it.

 

[helterskelter]

I didn't think it could be "over cured" but then again I have never done the process myself either.
I can see where parts done in quantity on an assembly line wouldnt be blasted etc like the Ford truck parts I referenced above... probably stamped and then sent for PC with mill scale, oils etc still there certianly I doubt they blast anything, in such a setting.

so any comments on various paints, whether bake on, spray on, hardener added or not, in comparison to having something PC'd?

I'd be shocked if parts weren't degreased and blasted prior to PC on any non 3rd world assembly line. The cost of quality problems associated with poor coating would be insane. There's no benefit to improper surface preparation. Assuming there's little masking involved, cleaning and surface preparation is CHEAP compared to the actual coating materials and warranty claims.

 

[Rockuf8]

The benefit is cost savings. I've hadany bought parts that didn't hold up to weather only to find the metal underneath smooth and brand new. They could care less what happens to their parts after a year.

 

[helterskelter]

The benefit is cost savings. I've hadany bought parts that didn't hold up to weather only to find the metal underneath smooth and brand new. They could care less what happens to their parts after a year.

There is NO cost savings to shipping coating that isn't adhered. We're talking about a quick run through a degrease solution, an oven dry, then an abrasive blast. All would be automated processes and add little to the final cost. If they sent parts to PC with oil still on them it would be failing at assembly, which means warranties. It doesn't take very many warranties to more than pay for proper preparation in the first place.

No major OEM supplier would coat something without at least an attempt at surface preparation (not saying it's not possible to have contaminated media or tanks, etc). I'm just saying any automotive supplier would not outright skip those steps as a 'cost savings'.

Junk aftermarket parts made in China are an entirely different story. But an OEM is going to have specs called out on their drawings that require preparation prior to coating.

 

[Rockuf8]

Yeah I'm not talking about OEM parts but cheap exported ****.

 

[Rockuf8]

I'm by no means an expert but I have had enough parts powdercoated that I am talking from what I have experienced personally, and I have befriended a few powdercoaters I use and know quite a bit about the processes.

 

[Crow Horse]

Sandblasting isn't required as long as a chemical pre-treatment step, ie. phosphate bath or spray is used.....

 

[volaredon]

Sandblasting isn't required as long as a chemical pre-treatment step, ie. phosphate bath or spray is used.....

if anything tahts what Ford must do w/their stuff as when the coating peels anywhere that isnt rusted thru is smooth metal not rough like it would be if sandblasted...
My son is getting into it at his job pretty deeply; where he's at, everything gets sandblasted. but he's still fairly new to the PC game

 

[Crow Horse]

I'm not sure what Ford uses or their process, but I do this daily as it's my job in the powder coating dept.. The phosphate treatment also etches the substrate. We sandblast when rust is an issue or the substrate has contamination within itself. When that occurs, we sometimes have to bake the impurities out and then start the entire process again.
PC failures generally are because of improper washing and improper curing. There are 3 tests that can narrow down the cause of the failure. Cross hatch test, acetone test. and a mil thickness test.
The washing isn't just washing and degreasing. It's somewhat complicated and pH, total dissolved solids, and titration must be measured for the washing procedure....
I have items I've PC'd closing in on 5 years left outside without any issue. Like any finishing, if you don't prep it correctly, it will fail.......

 

[Crow Horse]

Biggest drawback to powder is the inability to use any body fillers or such..if your doing dent repair or anything like that, powder is out.

Not entirely true. There is a product called Lab Metal that we use for such situations. I've only used it on aluminum but it works......

 

[Crow Horse]

To adress the OP's concern of a powder coated piece being in contact with concrete.... When we powder coat structures that will be sitting on concrete pads, we always sandblast, powder coat primer (zinc?), then finish powder coat with no known issues. Some of the structures we build are very large and we have one oven that is 55 ft. long to accommodate them. We have no known issues with structures sitting on concrete if prep'ed properly (read - primed).
On a side note, walking into a 500 degree oven and having to walk to the back of such a large oven is not fun. Working quickly takes on an entirely different meaning.....

 

[darkk]

Sandblasting isn't required as long as a chemical pre-treatment step, ie. phosphate bath or spray is used.....

Anything that needs to be coated, paint or powdercoat should have a surface that is prepped properly. Having used paint and powdercoat over the last 45-50 years, I would suggest the surface be degreased, dry, and most of all roughed up. Sanding, sandblasted or some type of abradding to allow the finish material to get a grip on. I have never liked relying on chemical adhesion. But for the OP's issue, The bottom of the lift posts is in contact with a rough surface. Just the natural expansion/contraction of the metal and movement from use on the concrete is like a sanding action. Over the years it will eventually wear/sand the finish off in small areas and expose bare metal to the the moisture which will eventually start rusting.