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Powdercoating help

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I posted this in the kx250f forum as well, i'm just looking for more help.

I've got the opportunity to get a pretty good deal getting some stuff powdercoated on my bike (clutch cover, valve cover, and ignition cover)

The the only thing i'm unsure about is the sight glass in the side of my clutch cover. I'm not sure that it will be able to hold up to the 400-450 degrees that the guy bakes on the powdercoat with. Any input will greatly help. Thanks.

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i dont think PC gets baked that high a temp, think its only about 325-350, and if so i think it would be ok, but cant say forsure!

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The heat the powder coating process uses is most likely gonna make the metal brittle. Wouldn't it be easier to just use spray paint? The powder coating is gonna wear away any how. Just not as fast as an enamel would.

Touch up the rubbed off paint from time to time, and save your bucks for a magnetic drain plug or something useful, right? I'd be more worried about the glass popping out altogether, when the metal expands in the curing process.

If you decide to do it anyway, make sure the painter doesn't spray the powder on the glass. He needs to mask that area off of course. Let us know how it worked out for you....

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Powdercoating does get baked at a pretty high temp, I would think that it would melt that plastic piece but I know people have done it. There might be a way to get it out of there but I'm not sure.

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you will be fine pcing it. It won't damage the glass or make the metal brittle :). If pcing made metal brittle no1 would do it:lame:

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you will be fine pcing it. It won't damage the glass or make the metal brittle :). If pcing made metal brittle no1 would do it:lame:

I'm assuming by that statement you have a degree in metallurgy?

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I'm assuming by that statement you have a degree in metallurgy?

how would it make the steel weaker? if powder coating only gets to lets say 400 degrees that isn't even close enough to change the integrity of the metal just warming it up. example lets say im going to build a custom tank for a bike using aluminum well i would probably have to do some annealing, annealing is heating up metal to be able to stretch the metal for a period of time before it cools while hammering it and that process needs to be repeated. you heat aluminum to about 800 degrees witch will only soften the metal for a period of time but not make it weaker or brittle. Same for steel you heat that to cherry red then start your hamming and so on an so on.. so i personally don't believe powder coating will make metal brittler by any means...

ps hope that made science

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I talked with several shops locally here, and they would not powdercoat my aluminum wheels. They said it could weaken the aluminum and cause cracking down the road....that being said I know of several guys who had street bike wheels done.

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Well, steel isn't the issue. If you heat steel, then quench it, you will make it harder. The parts of the bike we are talking about here are usually magnesium. Magnesium is brittle from the start, as opposed to steel, by it's molecular structure. Smack steel with a hammer, and it dents it. Smack magnesium with a hammer, and it shatters. The magnesium gives up strength, for weight savings. Therefore, the magnesium is use on a bike to make it lighter. Aluminum, although lighter, and less strong that steel, is another matter. Cast aluminum, such as in a motor block in a car is created with a mold. It too, has a tendency to crack, or warp. Just drive a few miles without a water pump working an your aluminum block will eat itself. The areas in the block where the heat of combustion are the greatest, as in the cylinder walls, are steel lined. The cylinder on our bikes is the same way.

I'm an airframes (ie. sheetmetal mechanic) on Army helicopters. We frequently fabricate fuselage parts out of soft, or "O" grade aluminum. We use the soft material because it is easier to form, into the intricate shapes we need. When the part fits EXACTLY, we then put it into an oven to harden it so it can stand the rigors of flight. The landing gear wheels we use are magnesium, just like the clutch covers and stuff on our bikes. Frequently, a pilot will land with too much speed, therefore requiring extrememly hard braking of the wheels. The brakes generate enough frictional heat at times to actually cause the magnesium itself to burn. (Yes, the metal itself actually catches fire). That same wheel, is ALWAYS replaced after a hot brake episode, because the next landing impact wll cause that brittle wheel to shatter. I'm not saying that the 400 degrees of heat that powder coating uses is going to make that clutch cover useless. But it is definately going to make it brittle. When you lay that bike down in a crash, and hit anything hard like a rock, you are taking a chance of busting that cover.

By the way, you're not going to ever heat aluminum to soften it to stretch it, or form it. You will forge it, by mechanically pounding it into the shape you require. Use Jesse James as an example when he builds his tanks using a machine that does the hammer forging. You can however extrude aluminum into a shape by heating it to just below it's melting point, and forcing it through a hole that is the shape you want. Think aluminum "I" beam for example. You can bet your ass that that aluminum is now more brittle than it was in it's original form. It's still a strong piece of metal though, because of it's shape.:)

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