corrosion protection in tail section of M20C

[DXB]

So I was trying to clean  the 47 years worth of hardened oily grime inside my tail section out, in preparation for possibly reweighing the plane.  I first tried Aero Cosmetics aircraft degreaser.  This did nothing. So then I tried a rag dampened with mineral spirits.  Wow that was stupid- no need to remind me.  Along with the grime, It removed a couple of small patches of the yellow zinc chromate primer that gives corrosion protection. So should I:

 

1. try to reapply zinc chromate to those two bare aluminum patches I caused?   The stuff is carcinogenic as hell.   

2. Maybe recoat those patches with Corrosion X?  The plane is due on it's 2 year interval to get retreated with Corrosion X anyway at annual this December.

3. Don't worry about it, if this is not a corrosion prone area?

 

 

[PTK]

I would reapply it Dev.

You can get zinc chromate in spray can from marine supply stores.

You may also consider zinc phosphate. Spruce has it.

[M20F]

Mineral spirits isn't going to remove zinc chromate or paint. I use it with a spray gun on my belly all the time and other parts to strip off gunk. So if patches are coming off something other is causing it to happen. Once you know what caused it to come off, fix that issue, than I would just clean/sand, and spray with zinc chromate.

Even though it is now chromated I would still Corrosion X it as the fog will bind to any parts in that section that didn't get chromated. The fog also works as a good lubricant to the moving parts.

[DXB]

Mineral spirits isn't going to remove zinc chromate or paint. I use it with a spray gun on my belly all the time and other parts to strip off gunk. So if patches are coming off something other is causing it to happen. Once you know what caused it to come off, fix that issue, than I would just clean/sand, and spray with zinc chromate.

Even though it is now chromated I would still Corrosion X it as the fog will bind to any parts in that section that didn't get chromated. The fog also works as a good lubricant to the moving parts.

Yeah I'd used mineral spirits on the peskiest areas on the belly paint before without issue, so I was a bit surprised.  Oddly only two patches (the larger approx 6"x6") came off, but the bare aluminum underneath, as well as the metal everywhere else in the tail, look pristine.  So I'm at a loss.  Maybe those patches were covered thin or not quite clean during the spray in '67.  I guess I should reapply with the similar yellow marine stuff.  

[carl]

i can send you some chromate stuff if you need some to try .

the prime with epoxy primer

.

.

[tony]

I think you can buy a spray can of zinc chromate and I would re appy it in those areas you rubbed off.  If you are going to keep going and want to get it clean, I've used nonchlorine brake cleaner with good results.  It doesn't remove the zinc chromate and does a reasonable job on 50 years of grease and grime. 

[carl]

How did you get in there ? I was thinking about climbing inside but then I thought I might crash through .

[tony]

I just crawled in and started spraying, being careful to put my weight on a rib.