Powder coat vs anodized - we want colors

This is from a thread that went off topic.

Question is, colored metal, have you done it, how does it look, what is the process, if VEX made colored metal would you buy it, what colors would you want.

In my limited VRC experience I’ve done VEX Explorer that came with black metal. I’ve had powder coating done ( a three day process) that the team loved. Anodized metal is possible, but I dimly remember that it’s a pale color when done.

@Scott_Shaw this is your post, how were the colors done?

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I’ve paid to get done… dye intensity improves with porosity of the metal, so a dip into a sodium hydroxide bath to clean and open up the pores can help.

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We powder coat ours, it has worked well assuming we pick good colors lol

Can you post a picture of the metal please?

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Sorry, was not vex metal. Some AL bar cylindrical bar stock.

In anodizing you are (ideally) building up the oxide layer. That’s what is porous and holds the dye. Wonder if that would have an effect on the ongoing static problem if the chassis was more of an insulator.

Those bots were indeed anodized if i recall correctly. Not my team, but i’ve talked to people on the team about it

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powder coating works great

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Reminder to all that the first time a vision sensor is confused by your colors… you’re toast.

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Exactly! All those painful memories come to life. :wink:

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Slightly off topic but our screw are color coded so we can sort them into correct lengths but would that be big enough to confuse a sensor?

No the heads are 1/4" in diameter, should not to confuse, unless there are a large number like 7-9 they can focus in on.

Glad to see powder coating works.

Just some FYI/background info: Much of VEX’s aluminum structure is clear anodized, so keep that in mind when determining the best paint/coloring process. The clear anodized aluminum is smoother and has a little duller look to it. The non-anodized parts will have a brushed finish (you’ll see lines/scratches on the surface of the metal). In general, only the really low production volume type parts will be non-anodized (accessory brackets, etc). It just depends on who’s manufacturing the parts for us. Our Greenville, TX facility can make aluminum structure parts, but we don’t have the capacity to make everything at that location.

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With our spray-painted metal, we noticed that typically, when a screw is fastened into a hole on the c channel, then removed, there is an ugly blemish where the paint was scratched off.

With powder coating, does that problem still exist? I know the coat is more resistant to wear, but can the paint withstand screws and nuts being attached to it?

Also, how well does anodized aluminum hold up over time? Competitions and practice are rough, and I was wondering how scratches and wear would show up on colorful anodized pieces of metal.

If anyone could post images depicting what I described, it would be greatly appreciated.

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The blemish is Aluminum oxide. Al forms an oxide layer VERY quickly when exposed to air. Abrasion wears this away, then it forms a new layer. Want to see something fun… check youtube for mercury and aluminum videos. You will understand why mercury thermometers are NOT allowed on airplanes.

Powder coating is a melted plastic layer. It can be abraded away. It can also chip and flake.

Most aluminum flashlights (mag lights/etc) are anodized. You can see what happens to them over time… dings penetrate the oxide layer, exposing raw/bare/silver AL metal.

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