Powdercoat is a bad thing

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elefantrider

elefantrider

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It appears gearbox oil ruined the powder coat finish of my frame. Replaced transmission layshaft bearing and some gearbox oil unfortunately got on the frame. The next thing I notice is powder coat on the frame has what appeared to be clear coat spots in that area. Anyone have the same trouble with powder coat and oils or cleaners?
 
elefantrider said:
It appears gearbox oil ruined the powder coat finish of my frame. Replaced transmission layshaft bearing and some gearbox oil unfortunately got on the frame. The next thing I notice is powder coat on the frame has what appeared to be clear coat spots in that area. Anyone have the same trouble with powder coat and oils or cleaners?
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Powder coating is usually very tough. Surprising that gear oil would have any affect on it. The down side to powder coating has been mentioned many times....gets in the way of frame/components attachment points. My frame was done in 1998 and still looking very good. Gear oil from both the gearbox and swing arm have gotten on that part of the frame with no affect at all.
 
This could be down to the quality of the powder used. The best polyester powders, which seem to be made in the U.S.A. would not be troubled by oil. Acid maybe, but not oil.
 
I damaged mine by accidentally getting some over spray of STP carburetor cleaner on it. It melted the coating but it hardened up again as cleaner evaporated. It looks like it just damaged the outer gloss finish not the base black an is under tank so the small dimples can't be seen. Petrol oils an even brake disc cleaner and thinners (though am more careful with the last two to avoid further problems) have no effect at all and the stuff is very hard to remove an can even be hit with a hammer and show little or no damage.
 
Over 40 bikes powdercoated with zero issues whatsoever.

After-the-fact welds touched up almost invisibly with gloss black Rust-O-Leum spray can.

Even good powdercoat CAN be scratched, but it takes a heck of a whack with a sharp edge to scratch it.
 
elefantrider said:
It appears gearbox oil ruined the powder coat finish of my frame. Replaced transmission layshaft bearing and some gearbox oil unfortunately got on the frame. The next thing I notice is powder coat on the frame has what appeared to be clear coat spots in that area. Anyone have the same trouble with powder coat and oils or cleaners?
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Did you have it powder coated or was it that way when you got it?
 
Bought the bike that way. Paint has been my preference for a long time now. (although powder is cheaper here)

Could it also have been caused by brake cleaner or WD40? I used both to clean the inside of the gearbox layshaft bearing housing, although not that much. Will try to post up a pic of the powdercoat damage.
 
I did a complete restoration of a Guzzi some time ago including a powdercoated frame. The first time I cleaned it with engine degreaser ( like I used on every other bike ) it destroyed the gloss on the powdercoat. I'll never use powdercoat again.
 
pommie john said:
I did a complete restoration of a Guzzi some time ago including a powdercoated frame. The first time I cleaned it with engine degreaser ( like I used on every other bike ) it destroyed the gloss on the powdercoat. I'll never use powdercoat again.
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Inferior powder product, without a doubt. I use degreasers from time to time on my bikes and I've had no such issues, even on bike that were powdercoated in 2003 - 2005.
 
Every frame Ive Seen streipped of its powder coating has had ( light ? ) surface rust . I assume its hygroscopic ! ? :shock:

Whats Wrong with SAtove Enamling , or dosnt the Devonport Naval depot do them these days . :D
 
I would think that any solvent or substance that attacked quality powder coat even to a small degree would blister and remove automotive paint. Epoxy paint is another matter. I have applied concentrated hydrochloric and sulfuric acid to epoxy paint with no effects.

Slick
 
Matt Spencer said:
Every frame Ive Seen streipped of its powder coating has had ( light ? ) surface rust . I assume its hygroscopic ! ? :shock:

Whats Wrong with SAtove Enamling , or dosnt the Devonport Naval depot do them these days . :D
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I wouldn't say it's hygroscopic, not after the powder is baked and crosslinked anyway. I suppose it could absorb water while still in powder form, but that's a pretty short duration. Rust underneath powder coating is likely poor preparation or poor adhesion and coverage, allowing water in.

Regarding the comments about brake cleaner damaging the finish...absolutely. Many brake cleaners contain acetone, which can and will melt/dissolve powder coating. A small amount of overspray will commonly leave spots behind after the solvent evaporates.

I've been powdercoating bike parts successfully for many years (>10), but have learned to be careful when working around powdercoated parts with strong solvents.
 
Powder coating is the same as any other coating process such as painting or electroplating. If it isn't done properly by skilled people using the best quality products & good surface prep. you will get a second rate job. The powder coat on my Hinckley Trident, which is now 25 years old, is still in fantastic condition. This bike was used for commuting to work on for the first ten years of it's life & was left outside in the sun & rain. It was lucky if it got washed twice a year. Nearly all of my fleet has been powder coated at Triple S in Yorkshire. They only do automotive parts. (mainly motorcycle) I wash them with engine degreaser, truckwash, petrol & paraffin, whatever is available at the time. Never had a problem.
The biggest problem with stove enameling these days, is most of the good stuff has been removed due to enviromental & elf & safety concerns.
 
I think one reason enamel gets a bad rap is that it takes a long time for the solvents to gas out and the paint to harden properly. That's the stove part of stove enamel, parts were heated after painting in industrial ovens to cure the paint faster. Most of us lack a facility like that to do a frame or any other large parts. The key then when using ordinary enamel is to let the part sit for a considerable period of time, months if possible before reassembly. If you try to start the day after painting, even if it's dry to the touch, the paint will absorb oils off your hands and any other stray lubes and will never harden correctly.

I recently did a Commando frame and bits with Rustoleum high temp engine enamel from a spray can and it looks really good. It sat for six months before I touched it and is nicely cured. The test for enamel to see if it is cured is to give it a sniff. If you can still smell paint odor(solvents) it isn't cured.

Not arguing that 2 pack can do a great job but if you lack the proper equiptment and protection, enamel can give decent results.
 
htown16 said:
I think one reason enamel gets a bad rap is that it takes a long time for the solvents to gas out and the paint to harden properly. That's the stove part of stove enamel, parts were heated after painting in industrial ovens to cure the paint faster. Most of us lack a facility like that to do a frame or any other large parts.
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So, powder coating is not heated in an Powder Paint Cure Oven then :?: :shock:
 
Oh how I miss the days when Marconi Communications in Chelmsford existed and had a nice big paint shop which offered me a 24 hour turn round stove enamal service.....as long as it was black! The plating shop did a similar service for chrome.....
 
I've had all kinds of crap on my powder coat and no issues here. I had it done by a fella that did PC for the DOD and also used a phosphate dip on the bare frame to prevent rust, even with a scratch. I've found like GP that Rustoleum gloss Black works great as a touchup. I had one of the tank mounting wings welded back on after the PC and it's nearly impossible to see, but it's also under the tank. I think people are getting an inferior PC job if standard solvents attack it.
 
I have found that any powdercoat I have used will be attacked by most solvents and oils -if it is very hot.

Carb spray and brake cleaner will attack it when cold.

I love epoxy stoving enamel.
It is killer on barrels. Much tougher than powdercoat -especially when hot. It's just pricey and hard to find.

I stick to paint on frames. It's easy to fix when it inevitably gets scraped, chipped or modified.

I use powdercoat or stoving enamel on small parts that can be removed and re-coated if needed. Jim.
 
A friend of mine who was doing powder coating for living told me once that for a good job, you also need to take the protecting tape off just after the powder begins to melt in the oven, so it would seal on the edges. But nobody is doing it today because it takes time...
 
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