Ok all you aluminum experts, I stripped a pair of 6x6 Cleveland wheels and washed them with aluma bright, (soapy phos acid) all but one half comes out pretty clean (white) one keeps turning black . Why

atomic number 12
Mg2+ + 2 e−
→ Mg

mr scout wrote:atomic number 12
Mg2+ + 2 e−
→ Mg

So that 1 half is alum/mag and not the other 3 halfs It kinda cleans up w/scotchbrite but not like the others. Should I not worry about it and alodine it and prime and move on

its possible its deeply oxidised but the wheel half could have been changed at 1 point. I would scuff it and move on, your alodine may not stick. If not try adding a couple drops of dish soap to your solution. If it still wont just prime and paint it.

Whats the soap do?

Scott wheels are magnesium. The alumiprep and alodine treatment are not effective. There is a treatment process for magnesium, just cant remember the product name. There is a pretty good reference manual online at Parker that talks about the care and maintenance of the wheels.

Some Cleveland wheels can be either aluminum or magnesium and usually come in complete sets. It sounds like you have 3 aluminum and 1 magnesium wheel half. I treated my magnesium Cleveland wheels with a Polyfiber product called Magnadyne available at ACS.

Iridite 15 is often used on magnesium alloys in aerospace. Alodine simply doesn't do the job satisfactorily on mag alloys- it leaves only a dim film, and the paint really doesn't want to stay on the part.

You can polish magnesium alloys with rubbing compound to get rid of faint scratches, but they will never look shiny. I use a rubber tennis ball screwed on to a shaft I can chuck up in a drill press or mill. You smear it with rubbing compound, run it up to 1000 RPM or whatever, and work your workpiece into the spinning tennis ball like a buffing wheel. Spinners, etc. all work well this way.

You usually don't use acidic strippers or acids in general to clean them; Turco makes some "environmentally friendly" stuff that won't burn your nose hair off. It works well if you are a bit patient- it is enzyme based or whatever, and is really not volatile at all.

scruiser wrote:Some Cleveland wheels can be either aluminum or magnesium and usually come in complete sets. It sounds like you have 3 aluminum and 1 magnesium wheel half. I treated my magnesium Cleveland wheels with a Polyfiber product called Magnadyne available at ACS.

Polyfiber? Hmm they're on my airport will magnodine clean it up and should I alodine it or skip it since it's magnesium?

Polyfiber? Hmm they're on my airport will magnodine clean it up and should I alodine it or skip it since it's magnesium?

I belive they are both known as "conversion coatings", that is they form a thin oxide coating that resists corrosion and promtes adhesion of the primer. Alodine is applicable to aluminum, and magnadyne is applicable to magnesium. I think magnesium has more corrosion issues than aluminum, and corrosion can occur quickly if not watched. Sometimes the felt dust seals collect water, and over time, that can do a number on that area of mag wheels.

"Alodine is applicable to aluminum, and magnadyne is applicable to magnesium"

All good information thanks all for educating me (and the lurkers )

Breaking news, Magna-dyne is no longer available. Precoat is the replacement chemical for magnesium.

Any downside to running two different metals on the same wheel? three if you count the bolts....

porterjet wrote:Any downside to running two different metals on the same wheel? three if you count the bolts....

You use up a lot of bandwidth trying to figure out how to strip and prep them.....

MTV