On aluminum how can you tell the difference if the items have been painted or powder coated? Also would there be a difference between a Clear coat paint and a powder coat?

As a former owner of a powdercoating company I say no way to powdercoat on drives or tabs !!! Why ? Well P.C show a ton of orange peel on flat surfaces and wont shine like Urethane and forget touching up P. C .
Here are my Outboard engine parts I just reconditioned for my Skater . All parts were blasted , DA with 80 grit , black epoxy primer , urethane straight up black and 2 coats of clear on top ot Urethane . The parts look like high end furniture .

I think he was asking how you can tell if a part he already owns is painted or powder coated???

It's tough to tell most times.

larry when are you going to have a garage sale? Is that a magazine rack in the background?...I thought you where using your black hair dye to make those parts shine...

Powdercoat always has orange peel

I wouldn't go as far to say that powdercoat "always" has OP. It's just a something you need to figure out how to avoid. Sometimes just not possible with production methods, but a custom coater should deliver a product free of any peel. It's definitely easier to get that glass look with liquid paint. I could direct you to a page full of pics of nice smooth PC.

Anyway. You could try some MEK on a swab and rub it on an area of the part in question. Most paint will transfer to the swab, properly cured Powder shouldn't. Be sure to try this in a hidden area it will leave a mark.

Found my answer, radar arch was powder coated. I was surprise to see that much marring from the shrink wrap on the Paint. Did not think that would happen to powder coat. In the process of rubbing out arch now. Should look like new ( I HOPE) when I get done.

It will ALWAYS have orange peel on flat surfaces m round parts like a cycle frame no because of the curvature of part you dont notice it . I had people all the times in my shop thinking that P.C was indestructible , far from it , Epoxy prime , urethane and if it needs a touch up no big deal , P.C good luck with custom color .

Ever try to P.C an old alum marine part ? That is a nightmare , outgassing

well I had a set of large trim tabs done a few years ago...they were slick(black)...no orange peel...still looked great 2 years later when I sold the boat...

It seems like glossy powder coat will have a little orange peel. Gloss black seems to be the worst. But, a lot of paint also has orange peel. When I was looking at new trucks all the red trucks had orange peel! Not sure if factory K-planes are painted or coated but they always have a ton of peel.

I think both paint and pc hold up well if done right.

I like powder coating cause it's much easier, and much cheaper for a "hobbiest". If I want to shoot a couple small parts it takes me 20 minutes including clean-up. The best part, sweep up the overspray!

I just painted my engine and it was a pita controlling the overspray. Hanging plastic, ventilation, controlling temp, controlling dust, clean-up, taping, etc.

I give props to the guys that do painting for a living!