powder coating - any good ?

[woodypup59]

People seem to bang on about powder coating.

But is it any good ?

Isn't it just another form of paint, once chipped or damaged the rust will start.

[Peter Laidler]

I often ask myself this too Woody. The paint is just a powder that melts on.

I had a similar - but totally different process - done on my S parts, by a firm ATO Chem in Thatcham. The difference was that they bead blasted the parts, primed them in a RILSAN, almost clear wishy-washy primer and sprayed the parts in a NYLON powder that was melted on and seemingly lasts forever. Had my Commando frame and the other odds and sods done too. But it wasn't paint.......

Unlike paint, nylon coating won't chip off. The only way it's coming off is to burn it off!

[Joel Welsh 4769VU]

Powder coating is indeed another form of paint.

However, it is different- in process, and in chemical content and makeup.

In basic-

It's in powder form, hence the name-
That is sprayed onto the part using an electrostatic charge to attract it to the metal.

It's an epoxy type bonded resin.

After its sprayed, its baked in an oven to activate the chemicals, melting them together, bonding them to the surface and curing them at the same time.

Cerakote is another type of epoxy bonded paint but in a liquid form with ceramic powders mixed in for durability.

[rolesyboy]

I like satin powder coat. Prepped/done well its brilliant.
The spring washers can bite in to it and cause it to break.
Otherwise I find it brilliant.
I've never had this issue where it flakes off and wotnot but I guess that is down to the competency of your powder coater.

The other thing to consider is this ceramic coating. A lot of mates with scooters and crossers use this on suspension parts. They really do rate it. I'm about to get some bits done to try it out.

[snoopy64]

A good powder coat, correctly primed and the correct thickness (important to stop cracking and chipping) is a very robust coating

[Polarsilver]

Then we come to major production car makes.. they powder coat their component parts & if like me you keep an older VW ..then have a look under when it is on the MOT Ramp.. the bodywork is bullet proof from corrosion but component parts have the Powder Coating splitting away with corrosion showing underneath.. me thinks the good or bad of any Powder Coating is about how much you wish to pay to get it done?.. so with my classics think it is better to prep & paint with a bit more care than BMC did back in the day.

[Oneball]

TVR chassis were powder coated, it cracks, water gets between the powder coat and metal and they rot. Personally I wouldn’t use it on anything out of choice.

[snoopy64]

Then we come to major production car makes.. they powder coat their component parts & if like me you keep an older VW ..then have a look under when it is on the MOT Ramp.. the bodywork is bullet proof from corrosion but component parts have the Powder Coating splitting away with corrosion showing underneath.. me thinks the good or bad of any Powder Coating is about how much you wish to pay to get it done?.. so with my classics think it is better to prep & paint with a bit more care than BMC did back in the day.

Absolutely right about paying to have it done properly... ask them to coat a piece of thin strip for you, if you can't bend it double and back several times without cracking, then look elsewhere.

[Exminiman]

Have had parts Powder coated in past, but as others said it will delaminate, giving a false impression of protection, also it seems to be thicker, which is not always helpful.

However, It is nice to take some skankey old parts to the powder coaters and get some nice clean shiny ones back


In the end almost none of our cars need it, they are not going to see the rain, let alone salt

[Spider]

I was put off it as being 'bad news' for many many years, based mainly on a lot of industrial products and also some stuff that 'restorers' have had done on automotive parts, including subframes.

In more recent times though, I have changed that view to a degree.

One of our Desert Rats had many parts Power Coated by a firm local to him back in 2011, some of these parts (subframes, fuel tank covers, sump guard etc) have literally seen hell, bashed, bumps, scraped and the like. I was fully expecting these parts to be full of rust when he started a strip down in 2018, with chipping and cracking of the powder coat letting water in and under as others have talked about here, but that's not at all what we found in this case. The various breaks through the PC were confined to just those spots. Looking closer at and trying to pick away at the PC, we found that it was deeply bonded in to the pours of the metal underneath and nothing in the world like the 'coloured plastic bag' that I've seen on other Powder Coating. Enquiring with the firm who did this, they said that the first abrasive blast the material, even if they receive it in that state, then bake the parts, while still very hot, apply the PC, then bake the parts again to set off the PC. They mentioned that most other firms skip that first pre-heating and that's why most PC ends up as a plastic bag type coating.

So, summing up, if done with a pre-heating process, it can be very good, if its not done with that, it can be bad news.

[Costafortune]

I have never had a problem with it. If parts are correctly prepared, powder coating works well.

[Joel Welsh 4769VU]

That's one of the main... issues, problems, highlights of any paint or chemical protection work on metal.

Preperation.
Paint is 90% preperation, and 10% application.
Thats the way i was trained.

I spent two years working in an industrial paint booth as a young man, and have spent many hours privately building/restoring firearms at home. I've done quite a few cerakote jobs on them.

My biggest focus is degreasing, degreasing, degreasing. Getting any and all oils and contaminants off the metal as humanly possible.

From there, i media blast the metal to a minimum 120 grit surface texture.

And degrease again and again.

Just for the epoxy to bite and bond to the pores of the surface for proper adhesion.

My one pistol i carry every day for the last five years since I've coated it- has worn off color. Down to the metal in many spots...

But not rusting.

[abs]

There have been some very good points raised for the pro and cons of power coating but my personal experience of the product over 30 odd years is not a good one.
To sum it up if it's your line of work and you can do it yourself PROPERLY it will be okay.
If you can watch the process and see it`s done properly it will be okay. You get what you pay for and it won`t be cheap.
Otherwise poly 2K paint as there are a lot of "one dust wonders" out there and I`m still bitter after spending years of my life bead blasting the crap off again to do the job properly.

[Stopped-again]

My experience of powder coating is varied, so what I say now is, if it’s under the car exposed to the elements and stone chips then paint it, if it gets damaged you can touch it up, where as with powder coating, if it gets any damage, moisture gets underneath it and it eventually comes off in sheets leaving rusty metal. But if it’s inside or under the bonnet then powder coating is brilliant. Just my experience.

[CooperTune]

I have been working with the same powder coater for so many years I'm not sure when we started. I drop off stacks of sub frames. He recently did three sets of S wheels OEW for me. We have worked out a system over the years. He starts with a chemical dip tank. Next sand blasting followed by cycle in the oven. First, he applies a coat of zinc rich primer. That is followed by a coat of chassis black then a flip and a second coat of black.

I'm about ready to remove a sub frame from my 85 1000 E. This was my daily driver for 17 years and over 150,000 miles. It will be interesting to see how it has held up. I like and expect I will continue to use it. Steve (CTR)

[Peter Laidler]

Not quite powder coating as such but we used to use a process called PHOSPHATING' or PARKERIZING as a rustproofing agent on our gun platforms - so any reasonable size was fair game! I'm sure that Joel will identify it. Bead blast and send through a tank of a phosphoric based solution and it came out with a deep to light grey (or khaki green if manganese in the mix. Through a hot oil bath and allowed to dry off. Rinsed and then painted with a diamond hard 'sunkorite' paint by HENKEL chemicals plus another whose name I forget - but they made the crackle finish paint for MG dashboards. Wet or powder. Both were as good. The painters said that the only difference was that there was less powder used. The paint/powder just protected the phosphating. The good news was that by design it was also extremely heat resisting, so better than anything I know for exhaust manifolds

We had massive tanks and most of my MGB GT V8 parts went through the system along with Landrover and Bedfoord lorry chassis. Alas, it only came through our system in 3 colours...... Khaki, black or yellow. Some 'hardware' recovered from Sir Galahad were still as good as the day it was bombed.

I wish I had access to it today

[richardACS]

My experience of powder coating is varied, so what I say now is, if it’s under the car exposed to the elements and stone chips then paint it, if it gets damaged you can touch it up, where as with powder coating, if it gets any damage, moisture gets underneath it and it eventually comes off in sheets leaving rusty metal. But if it’s inside or under the bonnet then powder coating is brilliant. Just my experience.

My experience too - I now prefer to keep it in house and wet paint.

I'm finding blast with alum. oxide to provide a nice key, followed by Eastwoods 2k paint is providing good results...

[Joel Welsh 4769VU]

PARKERIZING as a rustproofing agent on our gun platforms - so any reasonable size was fair game! I'm sure that Joel will identify it.

Yessir. Used on a variety of military guns and equipment throughout the decades by allied forces from I'm guessing- WWI to darn near the present time? You can likely still buy gun barrels treated with that process, or a very similiar one.

My M9 bayonet issued in iraq in 2003.
Normally a parkerized finish, this has held up 20 yrs so far!