[macrafic]

I had previously painted my interior with self-etching NAPA primer and primer sealer. To mount my antenna, I cleared a small area using Acetone so that the base doubler for the antenna would have a good ground connection to the aircraft. Then used a degreaser and water rinse (same procedure I've used for bare aluminum parts).

However, when I tried to alodine that small area, to provide long-term corrosion protection, the alodine would not take. I think it could have something to do with the "self-etching" components of the primer I used.

Has anybody else run into this problem? Any ideas for solutions?

 

[Mike S]

Did you acid etch before the alodine??

 

[apkp777]

What do you mean by "the alodine would not take"? If you mean it didn't dye the metal yellow, or it "beaded up", you can scuff with blue scotch bright and clean with MEK and it should work pretty well. However, if the alodine doesn't "take", I'd say neither would corrosion. Paint on.

 

[Flying Scotsman]

How old is the alodine? Has it been hit with UV for an extended period?

I had an older quart bottle of the stuff that was a few years old, and it, too, wouldn't "take" (just left the metal a very faint yellowish color). It had either expired, or been UV light-struck, or something, because I bought a new gallon bottle of the ****, and it worked virtually instantaneously on all parts. Now I have to figure out how to dispose of the old bottle (toxic waste).

If it's an older bottle of alodine, get some new stuff and I'll bet it works.

 

[macrafic]

Mike, I didn't acid-etch before alodining. Nor have I previously, without any issues.

By "not taking", I mean it doesn't yellow or golden; just remains shiny aluminum.

Alodine is good, since I just finished alodining the mounts for my antenna.

I will try scuffing with scotchbrite (which I had done before priming), cleaning and trying again. Hopefully the scotchbrite will clean out whatever is preventing the Alodine from doing its job.

apkp777, I wondered the same thing. If the aloding doesn't "take", maybe corrosion wouldn't either.