Observed corrosion on a candidate J model.

[Yetti]

Just now, Shadrach said:

On the inside?  Not likely...

No on the outside per the SB

[Shadrach]

58 minutes ago, Yetti said:

No on the outside per the SB

Per the SB he was inspecting the internal tube wall.  I think the external walls have already been inspected. He ran an endoscope inside the bottom tube per Part B of SB20-208B.  

[EricJ]

I just ran the endoscope down a gap between the interior plastic and the A-pillar region.   I think they're still the original factory coating, but they look good as far as any evidence of corrosion.

 

[gitmo234]

I guess the next question is... If it is corrosion, is the kind that you can brillo pad away and treat (I'm not actually suggesting a brillo pad, its an example) or is it one that requires full replacement. 

[carusoam]

External and internal tube inspection are probably good ideas...

There is also a device that measures pipe wall thickness.

When corrosion occurs with these tubes, the decay can be all the way through.

Somebody has posted some pretty ugly rotted tube pictures recently.

Best regards,

-a-

[thinwing]

Tubes look good...the corrosion I'm seeing in first pictures ,can be caused by landing on the many desert playas out west...that playa dust contains salts ,frequently alkaline and when it gets wet from tire spray starts corrosion even in dry desert conditions

[Yetti]

Still have the ADF in it?  I am guessing year to be 1978 to 1980

[EricJ]

5 hours ago, Yetti said:

Still have the ADF in it?  I am guessing year to be 1978 to 1980

Yup.  77.   I like the throttle quadrant, so that's a bonus.

[Shadrach]

18 minutes ago, EricJ said:

Yup.  77.   I like the throttle quadrant, so that's a bonus.

Yuck! 

[Yetti]

I have the throttle quadrant and like it.  My big Yetti paws can work all the levers at the same time.  The blue coax is the give away on the ADF.

[Piloto]

The corrosion spots don't look bad to me. Just a bit of surface corrosion that can be clean up with sand paper and repainted. This is common in old planes. Check the center spar cap splice on the floor and underneath. This is the water collecting point in Mooneys.

José

Edited April 15, 2017 by Piloto

[Shadrach]

17 hours ago, thinwing said:

Tubes look good...the corrosion I'm seeing in first pictures ,can be caused by landing on the many desert playas out west...that playa dust contains salts ,frequently alkaline and when it gets wet from tire spray starts corrosion even in dry desert conditions

I'm betting it's been landed on "the playa" a time or two. I wonder if the pilot will admit to landing at 88NV. I would never land my plane there. There is just no way to flush the funk out of every nook and cranny.

[Shadrach]

18 hours ago, EricJ said:

I just ran the endoscope down a gap between the interior plastic and the A-pillar region.   I think they're still the original factory coating, but they look good as far as any evidence of corrosion.

 

I stand corrected! It'd probably be a good idea to chec the interior of the tubes as well. Especially if it turns out to be a Burning Man plane.

[Yetti]

It was kind of a half ass painting of the tube frame.  You might want to use a brush to do all of the tube...  not just half.  I think you are in the year that the frame was not painted by the factory.  Looks like someone rattle canned the front side of that one tube and did not bother with that bottom tube.

[Shadrach]

2 hours ago, Yetti said:

It was kind of a half ass painting of the tube frame.  You might want to use a brush to do all of the tube...  not just half.  I think you are in the year that the frame was not painted by the factory.  Looks like someone rattle canned the front side of that one tube and did not bother with that bottom tube.

I don't know of a year that didn't get paint. The later birds got more sophisticated paint but I don't think any left the factory with bare steel.