Ok....With risk is reward, sometimes.

I think I am F$%^'ed on this one! I bought a 21 inch spoke smooth profile rim on ebay for $200. I was excited because these tend to be hard to find. I guess people hold on to them. Anyway, it gets here on Saturday and the inside under the rubber band has several areas of corrosion. Some not so bad and a couple of spots really blistered.

Question is, if I clean these areas up and treat them is there a risk for catastrophic failure? Are there service limits listed anywhere for this condition?

I have a feeling I am out $200

 

You're overly concerned with the surface corrosion you see. I can assure you it's not very deep at all and the structural integrity is not the least bit jeopardize.

I own an aircraft business and a large part of the services we offer are corrosion treatments and corrosion repairs.

You just need to sand it away. To do so you can use wet/dry sand paper working wet. You'll first sand thru the ash color thoroughly. If you see any black specs, you'll need to sand those away as well. They're the corrosive cells.

Once you're done sanding, just spray a thin film of LPS-3 on the area. If you can't do so for some reason (like sealing spoke) you can spray it with Zinc Chromate or Zinc Oxide. It looks like army green paint, so masking would be required.

If you need anymore help with this, feel free to PM me.

 

Thanks for the input PanHead.

I also have extensive background in aircraft maintenance, A&P holder with 10 years heavy structures experience and another 10 in QC/QA and NDI work. So at least we are on the same wavelength.
Having said that, I was going to blend it and treat with CB 55 and cover with zinc chromate primer. However, a couple of spots look exfoliated pretty bad. You know how it goes, once you start chasing it, it may go deeper than it looks. I can send you some pics via email and you can let me know what you think. I know most aircraft mfgs i.e. Boeing/Airbus allow 20% blends in most areas with out engineering review, I just don't know what a Harley rim will take..lol.

 

I would suggest using Scotch Brite pads to feather out the corrosion, 20-1 blend, per Boeing Structural Repair Manual, Chapter 51. (Pads on a die grinder will make short work of it)Treat affected areas with Alodine (to chemically treat the raw aluminum) then apply top coat of Zinc Chromate. However, and there ALWAYS a however, you mention exfoliation. That sucks big time. Since exfoliation is an induced inclusion due to improper heat treatment at manufacture, it can extend undectected well beyond what is visible on the surface. I am in the process of changing the skin on the entire vertical stabilizer on a Large biz jet. (Global Express if any one else keeps up with that stuff). Exfoliation caused it. So I would say your concern is justified. Good luck.

 

Thanks bud...lol I love the Boeing reference. I think the corrosion is from the dissimilar metal contact of steel spoke nipples and aluminum rim. Add heat and moisture and there you go....
I will high speed blend and see where it's at...I think I am out my money...FML

 

found this while looking for U..
http://www.thumpertalk.com/forum/arc.../t-333970.html

 

another daily double post.