When powder coating do you want to get it sand blasted first or what? Do you have to bring it to them with all of the mill scale off of it? Maybe I just take it there and they do what needs to be done. Maybe I will have to pay them to do it when I can do it myself and save money. How ill they get the inside of the square tubes powder coated? I'm building a bookcase and was just going to paint it but have been thinking about getting it powder coated.
Explain powder coating to me!!!
- Thread starter skipnay
- Start date
Yes the metal needs to be clean and free of contaminates and only very mild surface rust if any. I've never ran across a PC guy that didn't blast prior to application with the only exception for me anyways of doing clear over a polished finish. I would however suggest you spend the time to clean all the scaling off and let them finish the prep.
If I have to get the scaling of I can take it a place that sand blasts really cheap. They did my 30" x 8' piece of steel both sides. It was real rusty and pitted. They charged me $25.
Ya. Heck take it to the PC guy and ask what he would charge, you might be pleasantly surprised and not need to make two trips. The guy I use is a total rock star and all though I've never taken anything to him that needed any major prep have no doubt he'd make certain it was done properly. But I can tell you that far too many times I've had customers bring stuff in that it was painfully obvious the PC didn't do **** and the finish quality lacked badly.
stercorarius
Well-known member
Good info to know. What kind of prices do you guys pay (ballpark figure) for getting like a small service cart (frame no drawers) powder coated?
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Todd.Brock
Well-known member
CudaChick might pop in. She runs a powder coating business. Phoenix specialty coatings, I believe. I think she has some samples and prices on her website. May give you some direction.
tonyciambrone
Well-known member
The part also needs to be off gassed or free of oil entirely, otherwise there will be blemishes or the finish won't bond properly.
Aluminum seems especially porous, I've seen oil come out of aluminum parts during preheating for welding.
Aluminum seems especially porous, I've seen oil come out of aluminum parts during preheating for welding.
astroracer
Well-known member
Sand blasting is required, not only to clean the metal but to give the plastic something to grip.
A full service Powder coater will be able to prep the parts prior to coating. It will be an additional cost.
After prep the coater should bake the parts up to about 600 degrees to "boil off" any left over oil or other contaminants.
prices are going to vary widely, no one can give you a ball park. you will have to talk to your local guys.
As an example: One shop near me does stuff very cheaply. I had him coat some F1 Ford Chassis brackets a few years ago. 11 pieces from spring hangers to trans crossmembers and they charged me 40 bucks. I did all of the prep work and the color was black.
Mark
A full service Powder coater will be able to prep the parts prior to coating. It will be an additional cost.
After prep the coater should bake the parts up to about 600 degrees to "boil off" any left over oil or other contaminants.
prices are going to vary widely, no one can give you a ball park. you will have to talk to your local guys.
As an example: One shop near me does stuff very cheaply. I had him coat some F1 Ford Chassis brackets a few years ago. 11 pieces from spring hangers to trans crossmembers and they charged me 40 bucks. I did all of the prep work and the color was black.
Mark
I think one has to be very careful about the fundamental principles of anything and prevent taking lazy approaches to understanding things.
Powdercoating does not "require" any sort of surface processing. The basic definition of powdercoating is the application of finely powdered thermopolymer, designed to fluidize and crosslink at specific temperatures (usually high temperatures, but can vary.)
Because you're attempting to adhere fine powder to a substrate, the industry has standardized application through the use of electrostatic attraction between the substrate and the powder itself. The advantage of this is that coatings can be much more uniform than typical (because the maximum thickness of the electrostatic coating is tightly controlled by the electrostatic charge applied to the powder itself.) The big disadvantage of the electrostatic method is anode shadowing.
However, powdercoat can be applied by any number of means, including solvent-borne spray and brushing if necessary.
Surface treatments to the substrate are identical to any other painting method (rattle-can, etc.) You can theoretically apply powdercoat to any surface condition - even dirty and greasy, but the end result will be low adhesion - just like acrylic urethanes and two-part epoxy finishes. You can apply powdercoating directly to mill scale, but its adhesion will be no different than the adhesion of other finishes directly on mill scale.
If you are engineering a finish, and you have the luxury of specifying an adhesion in psi, and that specified adhesion is low enough, then you can get away with very little in the way of surface preparation.
That said, typical epoxy and polyester TGIC based formulations on powdercoat are approaching 2000-3000psi surface adhesion. If you have an intermediate layer between the powdercoat and the base metal, the intermediate layer adhesion to the base metal must equal or exceed the powdercoat itself, otherwise, you will end up with peeling, etc.
Powdercoating does not "require" any sort of surface processing. The basic definition of powdercoating is the application of finely powdered thermopolymer, designed to fluidize and crosslink at specific temperatures (usually high temperatures, but can vary.)
Because you're attempting to adhere fine powder to a substrate, the industry has standardized application through the use of electrostatic attraction between the substrate and the powder itself. The advantage of this is that coatings can be much more uniform than typical (because the maximum thickness of the electrostatic coating is tightly controlled by the electrostatic charge applied to the powder itself.) The big disadvantage of the electrostatic method is anode shadowing.
However, powdercoat can be applied by any number of means, including solvent-borne spray and brushing if necessary.
Surface treatments to the substrate are identical to any other painting method (rattle-can, etc.) You can theoretically apply powdercoat to any surface condition - even dirty and greasy, but the end result will be low adhesion - just like acrylic urethanes and two-part epoxy finishes. You can apply powdercoating directly to mill scale, but its adhesion will be no different than the adhesion of other finishes directly on mill scale.
If you are engineering a finish, and you have the luxury of specifying an adhesion in psi, and that specified adhesion is low enough, then you can get away with very little in the way of surface preparation.
That said, typical epoxy and polyester TGIC based formulations on powdercoat are approaching 2000-3000psi surface adhesion. If you have an intermediate layer between the powdercoat and the base metal, the intermediate layer adhesion to the base metal must equal or exceed the powdercoat itself, otherwise, you will end up with peeling, etc.
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sberry
Banned
That is really good.
SteveH-CO
Well-known member
And once water gets under powder coating and the steel begins to rust and blister the powder coating, you would have been better off with paint. This is not so much of an issue in dryer parts of country, but if you have rust bubbles under the powder coating on (for instance) your snow plow blade, you might as well chip off the powder coating to slow the decay.
I'm a powder coating fan for its chip resistance and ability to cover small surface imperfections, but it's not a perfect coating in every situation.
I'm a powder coating fan for its chip resistance and ability to cover small surface imperfections, but it's not a perfect coating in every situation.
sberry
Banned
I was thinking the same thing, not so sensitive for a shelf indoors but for other stuff that's the sheet water gets under and peels off. For a shelf get some hi gloss spray paint.
Thanks for all of the help..
This is the place I'm going to use. http://www.biltwoodcoatings.com/index.html Some what local. I have a local place but two different people had problems with them and not standing by there work....
This is the place I'm going to use. http://www.biltwoodcoatings.com/index.html Some what local. I have a local place but two different people had problems with them and not standing by there work....
CudaChick1968
Member Emeritus
Thank you for the mention Todd! 
Sonoronos, that has to be one of the most concise, intelligent responses to that question I think I've ever read. Simply put, it WILL "stick" but proper metal prep is key to longevity and durability. Whoever you decide to hire skipnay, make sure you get to see REAL samples you can touch and inspect rather than photos taken from five or ten feet away. There are just too many rookies out there nowadays who call themselves powder coaters.
Sonoronos, that has to be one of the most concise, intelligent responses to that question I think I've ever read. Simply put, it WILL "stick" but proper metal prep is key to longevity and durability. Whoever you decide to hire skipnay, make sure you get to see REAL samples you can touch and inspect rather than photos taken from five or ten feet away. There are just too many rookies out there nowadays who call themselves powder coaters.