The International Cessna^® 170 Association

bradbrady wrote: John,
With all due respect I have an isue with last resortany one using sand paper on any aircraft! The Aclad can be taken off with the aformentioned (very good products) If your going eventualy take an aircraft through its alclad you need to paint!!! : There is no other way to keep the skin in good shape just my humble opinoin! let's see what others have to say.
brad

Sanding is definitely an advanced technique and not something to be taken lightly, but it is not uncommon when restoring aluminum to do some sanding when necessary. To keep the skins in good shape just keep polishing . Proper polishing does not remove any material, just turns it over.

From the Perfect Polish site:

Will repeated polishing remove the Alcad coating? Not according to Boeing. As a quality control measure Boeing polishes all of their exterior skin sections after forming using robotic polishers and Nuvite F-7. Apparently defects in the skin are easier to spot when polished. They once polished a section 370 times and the surface cladding (Alcad) was still there. Boeing says that polishing does not remove metal, it just "turns it over." Of course if the surface is badly corroded or has been sanded, the Alcad will be gone. But it will polish up nicely anyway.

bradbrady wrote: John,
With all due respect I have an isue with any one using sand paper on any aircraft! The Aclad can be taken off with the aformentioned (very good products) If your going eventualy take an aircraft through its alclad you need to paint!!! : There is no other way to keep the skin in good shape just my humble opinoin! let's see what others have to say.
brad

Hmm.... I'm way out of my depth here, but if the purpose of the Alclad coating is to prevent corrosion, doesn't regular cleaning and polishing accomplish the same thing? I don't doubt that corrosion might happen more quickly if the surface is left alone, and if so, paint would be required. But these surfaces are getting regular maintenance with Nuvite, and have no long-term exposure to the elements.

We're using the 600 grit only where there are deep scratches to remove. This can be done by compounding with a rotary polisher and the coarser Nuvite abrasives, but the 600 seems to get you to the same place much more quickly. I'll listen to what others have to say now.

Best Regards,

John

John,
I tryed to Quote your last statment but wasn't able to make it go! What I was trying to say it dosn't matter how you are pollishing your A/C you are alwayse taking the alclad off, and it dosn't matter how (pollishes or sand paper you are killing the alclad!!!! ) once you are through the alclad and have no other cover you have a problem with your A/C! This is like something that will never happen in my opionion, but stuff happenes and I just wanted to give you the heads up and keep you thinking
brad