Powdercoating effect on wheel strength!!! - PeachParts Mercedes-Benz Forum

samiam4 · #1 12-18-2002, 11:39 PM

Hi Everyone,

I searched on wheel painting and there were implications that powdercoating may reduce the aluminum strength of the wheel.

Well- I couldn't answer it at first. I grabbed Mil-Handbook-5h and still no help. Today I talked to some *very* knowledgeable metals engineers.
Based on All the alcoa data they had maintaining 300-500F for 1/2- to several hours has a neglible effect on the strength. Since, I don't know MB's alloys, we speculated on lots of things.
IF someone saw shorter life, with cracking, it should have been caused by prepping. I suggest sticking to a mild beadblasting vs an aggresive sandblasting. If you are racing orientated, you could have them shot-peened after beadblasting. Then coated.

Hope it helps! Now, just have to find a good local place=)

Michael

#2 12-20-2002, 11:28 AM

on the FACT, well known in _Hot Rod_ and similar journals, that chrome plating reduces the strength of steel. Do any of your professionally qualified sources know whether chrome plating can also reduce the strength of aluminum? (Not that I care -- I much prefer the real aluminum appearance anyway.)

samiam4 · #3 12-20-2002, 12:32 PM

I'll have to ask-

yes, Chrome plating definately reduces the fatigue life to steel. It is very well documented in every mechanical engineering machine design textbook I have ever seen.
If you look at broken crankshafts, many times the radius size and or chromeplating was the direct cause.

Michael

J.HIDALGO · #4 12-20-2002, 09:03 PM

I know chrome plating has a weakening effect on metal(s). I do not know of any negative effects of powder coating on metals. Am I missing something?

samiam4 · #5 12-21-2002, 12:54 AM

J.

Your not missing anthing. I did a search on wheel painting and there was past discussion about strength reductions on powdercoated wheels. All metals which are heattreated or in the case of AL's aged-tempered or what ever, are basically annealed at higher temperatures.
So, the concern was what happens to the aluminum wheel when it is heated to 300-500F to melt the powdercoating?

Michael