Powdercoating anyone?

[560Dennis]

How much time do you put into the cleaning of your parts ?

 

[Don B.]

Hopefully enough. I glass bead everything. When I did the calipers I took them completely apart and put old used pistons in for "plugs" and taped them in so to keep powder out of the seal groove.
If I don't get to coat something right away after blasting sometimes I have to put the part(s) back in the cabinet and hit them again right before I coat them.... Not always. I've had stuff sit over the winter and be fine. and I had stuff that flash rusted in a couple of days between blasting and coating. I blow everything off just before coating, and sometimes I wipe it down with Eastwood's "pre" cleaner. On those calipers or anything else that "lives" in oil, brake fluid, etc I toss in the oven and bake until the parts quit smoking then I know I ve gotten the oil etc out of the pores.

 

[Don B.]

I see I posted a lot of what I just put in that last post in a post about 3 or 4 posts ago....

 

[Don B.]

Well update on the powdercoating....

The $40 oven I got from CL still working somewhat. It's a free standing one with a stove top. I removed and scrapped the coils. It works ok for hanging parts from the racks with hooks made from cut up coat hangers. But if I have to use the racks like you would with cookie sheets and slide something in on the racks it's not ideal. It has an upper and a lower heating element. I've never seen the upper one lit up. I had a pair of 3/4 ton truck brake rotors in there. (I just coated the fins and the hubs) and I keep track of temps with an infrared temp gun .. the lower rotor was 50* hotter than the top one, the lower one being closer to the temp I have the timer set to.
And im tired of dropping my freshly coated parts because of having to bend over and hang them from the racks with needle nose while wearing welding gloves.
So for the price of an upper heating element from the local used appliance place I found a "built in" style double oven that even came still mounted in its kitchen cabinet.... So I can load and unload parts straight in and out without so much bending down. With the double configuration each compartment is smaller but overall I have more top to bottom space. It is narrower, as it's only a 24" oven vs the free standing one being 30.... I'm gonna see if I can squeeze both of them in the space I have since the first one does still work....

 

[Don B.]

I'm not ready for a commercial PC oven quite yet ...

 

[Don B.]

I've considered doing it myself and also had it done. But a couple of years ago I brought a set of Allis rims and the fenders from my tool trailer to the powder-coaters I used at a former job and for some home projects, and they surprisingly told me they wouldn't recommend it for all the reasons stated above. It's a great, durable finish that'll last ages in static applications. But if you scratch/ding it (which you're inevitably going to do on a set of working rims before too long, and will definitely do with a set of fenders in no time) and it'll just harbour surface rust behind it and eventually peel off. They told me a good epoxy sealer/primer and a good top coat would be better, which is what I did.

I do plan on coating some of the wheels on my garden tractors....
And on my truck project for the prices I'm seeing on parts both new and used i'm way ahead to take the time to clean and (either) paint or PC (depending on what the part is) vs just buying replacements....
I'm definitely interested in "testing" how durable my PC job will be....
I was looking for something else and I see (for example) I can buy new reproduction battery trays. I have 2 good ones here already. Why pay $100 for a new one????

 

[urbancase]

Don if you looking to upgrade down the road, start looking at used industrial equipment dealers. I know the oven used on production line are vary big but you may find something from a job shop that does just a few at a time. I picked up my machine shop stuff like that.

 

[mrhud]

heres my problem with things that have been powder coated is by the time you see a blister on the powder coat finish everything underneath is compleatly rotted away and instead of sanding and primuing something it has to be refabricated flat beds on pickups have to be the absolut worst car parts rot from the inside out , if it has bolt plate or somet thing it will rott out aleast the paint just gets a little rusty looking

 

[showcrop]

heres my problem with things that have been powder coated is by the time you see a blister on the powder coat finish everything underneath is compleatly rotted away and instead of sanding and primuing something it has to be refabricated flat beds on pickups have to be the absolut worst car parts rot from the inside out , if it has bolt plate or somet thing it will rott out aleast the paint just gets a little rusty looking

Yes, that is the basic problem with powder coat. It provides protection for the rust, keeping it warm and keeping water trapped in behind it, so that it can keep eating your steel.

 

[Don B.]

There's problems with every option. I've had paint fail too. There's more different types of paint than powder, and I'm not talking colors.
And there's "cheap" paint and expensive paint. I've had them all hold up and all have failed in some way. Lacquer, enamel, urethane, base/clear, epoxy and more.
And I've seen powder peel in sheets just like I've seen paint do. Almost every part I have coated in this project came from the factory as bare metal.
And my experience with powder so far seems to be that assembly line PC' d parts seem to hold up "less well" than parts coated after. In an assembly line setting I think they have too much volume to really clean up what's being coated.
Just like paint surface prep is everything.
These parts I'm coating, (so far) are going on a truck who's days of living in salt of winter are done. But it will get driven quite a bit the rest of the year. Like I said for the most part these parts were bare from the factory. Some like the door and hood hinges were originally painted.
If all powder blistered peeled and rusted like you guys said nobody would use it. It would go away.
I'm playing with something new to me here and I'm interested in how it's gonna hold up as well.
Alot of it is getting paint instead of powder. The frame, the front control arms, springs, rear end, anything not easily removed from the frame or won't fit in my repurposed kitchen oven is getting paint. And not cheap paint either. $500/gallon industrial 2 part epoxy paint and it's suggested 2 part epoxy primer underneath. So hopefully that holds up. I just painted the rear end with this stuff last night even.

 

[showcrop]

The whole point to factories using powder coat is to get out from under the VOCs laws and expense. This is mostly true of outfits like trailer manufacturers that aren't making many different things that some of which would need painting. There would be no point to powder coating if they were to prime them first.

 

[Don B.]

But there is powder primer.... Which also gets baked on before coating with the final color.
But the surface still has to be clean even with that... No oils, mill scale rust, etc. can be present just like with paint.
With the sheer scale of production there's no way to sandblast everything right before PC.
Just like with paint you won't be happy with the results if prep isn't done right.

 

[Don B.]

I tell you what
I just had an oops powdercoating.
I had doubts about the oven I have as to whether 1 or both heating elements work
Well I guess the top one does work if I turn the dial up enough haha
I literally burned the powder off of part of a brake backing plate for my truck project
What wasn't burnt and blistered does NOT want to come off... I've got more time than I care to try and count in re blasting this plate so I can do it over again.
Part of the learning process I know but the point is if this stuff doesn't want to come back off in a blast cabinet with black beauty then I really don't have much worries about durability of powdercoating...
As I have said somewhere whether in this thread or another. alot of what I'm coating was bare when new from the factory anyway. And I plan to drive this truck but no longer in salt and snow once done. It's 43 years old now. so anything I do to it should help it last at least that many years more.

 

[Dick L]

good today as when it left the factory. Hard as nails and no flaking.
If you’re having problems with powder coat I’d say it’s an issue with the person not doing it right or a bad powder coat product. The materials and process Landoll uses is much better than regular paint.

Using the correct for the application is the secret as well as the proper prep. Spending my life in plastics the plastic industry, I watched the wrong plastic specked and fail. The designers of the parts were not aware of the durability of the materials. I bought a powder coating system and after doing a lot of research I decided It would be better to put it in a corner rather than buy all it would take and then to go in the red on my small project. Remember when it would be stated (made out of cheap plastic it is junk) Most of the car interior is plastic. Same plastic base material I use only in powder form. Powder coating needs a primer on metal to keep it from pealing the same as painting a car. The plastic powder has to then be compatible with the primer.










f

 

[Don B.]

There is a primer that gets applied as a powder and baked just like the final coat but a little less hot and a little shorter time. Id rather apply powder color over powder primer than to try and chance it with a solvent based paint product.

 

[Dick L]

There is a primer that gets applied as a powder and baked just like the final coat but a little less hot and a little shorter time. Id rather apply powder color over powder primer than to try and chance it with a solvent based paint product.

Yes, I should have said baked on. If everyone knew what I am thinking I wouldn't have to stutter explaing myself as much.

 

[Don B.]

I get that but didn't know if others reading it would have.

 

[Don B.]

I powder coated the drums but not the hubs (I didn't want to have to fight getting any leftover sand crystals out of the cavity that would eat my bearings) the wheel studs hold the drum and hub together. The backing plate (gray) is powder coated as well as the e brake lever and the little plungers that stick into each side of the wheel cylinders. The hub is 2k epoxy painted after the whole rear end was blasted and painted with that while the whole rear was still together and sealed up... That 2k was actually a primer (Sherwin Williams industrial/Marine grade) but is still said to be a 15-20 year paint product. I did spray paint the rest of the rear end housing over that 2k primer in semi gloss black with another industrial epoxy 2k Sherwin Williams paint called high solids polyurethane.
(A Dana 60 won't fit in a standard kitchen oven)
Everything I powder coated here was primed with powder primer and cooked/cured as label said which was a little cooler than the black and gray you see for about half of the time of the coat you see in the pix. I pulled these parts out warm and put the color coat on "heated up" and then put the parts back on the oven at the full 400* for 20 minutes after the parts were at oven temp as monitored by a hand held infrared temp checker. I got the oven cheap enough from Craigslist, cheap enough it craps out I go get another one and the gun I got from Eastwood is always on some kind of sale deal..
Im way past the original pile of parts I wanted coated and don't have nearly the amount of money tied up in the whole deal as I was quoted by 2 places... Even though I have had a couple of redo's because of learning pains or a wrong choice of color shade... And still have powder left, the application gun and the oven to do further parts without any more cash outlay...
It's pouring here today so I don't have to worry about not being able to spray paint because of that or the wind or when I started asking about coating it was biting azz cold out... I already have a honking 2 stage compressor and a sandblast cabinet and have had for years...
As has been said much of what I coated left the factory bare back in the day... I have enough money in this truck besides what little bit I have in the powdercoat stuff that I don't want everything to rust and look like my efforts were wasted in short order, all of this is an experiment of sorts anyway, at worst this will delay the rusting process way longer than leaving everything bare. So we'll see.

 

[Don B.]

Here's the back side of that backing plate you see with the shoes mounted above....

 

[showcrop]

Columbia Coatings has an excellent You tube video on how to choose the correct primer paint for your project depending on the substrate, and the intended use, to enhance the likelihood of success.