Skymaster Forum  

Go Back   Skymaster Forum > Messages
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
Thread Tools Rate Thread Display Modes
  #1  
Unread 12-18-21, 06:56 PM
Joes Joes is offline
Registered User
 
Join Date: Dec 2021
Location: Abingdon, VA
Posts: 7
Joes is on a distinguished road
Prebuy on airframe corrosion.

Any specific areas to be inspected for corrosion? Other outstanding issues a novice may need to be aware of, it's a 73 P with 3300 A/F hrs.
Reply With Quote
  #2  
Unread 12-18-21, 08:49 PM
hayesjaj hayesjaj is offline
Registered User
 
Join Date: Apr 2019
Location: USA
Posts: 54
hayesjaj is on a distinguished road

Bad spots I have found are on the interior, located on the inside surfaces of the skins. Cessna used lead vinyl "vibration absorbing" pads with a certain glue that holds water to attach them to the aluminum panels. If any water gets trapped, it causes the skins to corrode. I found a bunch of this on my 1973 337G restoration.

The fuel tanks can also have corrosion issues in the bay and on the tanks themselves.

Finally, around and under the avionics bay access hatch has a known issue. Others may have found spots to include to this list.
Reply With Quote
  #3  
Unread 12-19-21, 01:22 AM
bjornfb bjornfb is offline
Registered User
 
Join Date: Apr 2019
Location: Portland, Oregon
Posts: 18
bjornfb is on a distinguished road
I just had to have my whole horizontal stabilizer reskinned due to corrosion, so I’d suggest looking inside there as well.

-Bjorn
Reply With Quote
  #4  
Unread 12-19-21, 04:28 AM
wslade2 wslade2 is offline
Registered User
 
Join Date: Feb 2016
Location: none
Posts: 184
wslade2 is on a distinguished road
Under the battery box all the way down to cowl flap including muffler support. In fact muffler supports both sides. Skin near and downwind from battery region and vent.

Wing roots under the fairings where wing joins fuselage. Those fairings poor at keeping out water. Includes wing attachment hardware. Struts can be overlooked (due to fair number of screws to completely expose those; also the fairings at the ends can be difficult to remove-mine we’re even riveted in place impeding inspection) and check those.

Bottom of rudder in case lower rudder tips poorly drain and hold water.

Last edited by wslade2 : 12-19-21 at 04:43 AM.
Reply With Quote
  #5  
Unread 12-20-21, 01:20 PM
hharney's Avatar
hharney hharney is offline
Forum Administrator
 
Join Date: Jul 2002
Location: Michigan (8D4)
Posts: 2,208
hharney is on a distinguished road
I have a super clean airframe, 1968 C model, but there was still corrosion under some of the dampening pads in the interior so that may not be the first place to look. Those are not easy to access either so I would check some easy spots first.

Like the previous post above on the elevator, I would closely inspect the trailing edges of the elevator and ailerons. These are tight areas that salt moisture can get trapped and will show corrosion first. Also pull the under wing panels and with a good light see how much white dust type accumulation is present. It can vary from none, with shiny aluminum to ugly battery acid look. Areas posted above that are easier to access will give you a good indication of the condition. Also just reviewing log books and history of location (internet search) will help to reveal any suspect reason to start searching in the harder to reach areas. Some of the areas are just a given that corrosion will be there. Most experienced A&P’s will know the task.

The last thing I would suggest is discipline yourself to walk away from a disaster after crossing several issues. Don’t get emotionally attached to the outside beauty of the Skymaster. Be prepared to expect the worst. There’s just a lot of junk out there. It takes time and energy to find the one.
__________________
Herb R Harney
1968 337C

Flying the same Skymaster for 45 years
Reply With Quote
  #6  
Unread 12-20-21, 01:42 PM
hayesjaj hayesjaj is offline
Registered User
 
Join Date: Apr 2019
Location: USA
Posts: 54
hayesjaj is on a distinguished road
Couldn't agree more Herb. I forgot about the trailing edge, and mine does have a small issue on the outboard RHS flap in that location as well.
Reply With Quote
  #7  
Unread 12-20-21, 03:53 PM
n86121's Avatar
n86121 n86121 is offline
bigcheese
 
Join Date: Nov 2003
Location: Potomac Airfield~!
Posts: 203
n86121 is an unknown quantity at this point
ACF 50 / Corrosion X

This reminds me, when I was commuting for 22 years along the ocean to the Outer Banks, down low: Every 2nd or 3rd annual, when it's all opened up, have the entire airframe fogged with ACF 50 or Corrosion X. Stops the clock on corrosion.
__________________
David Wartofsky
Potomac Airfield
10300 Glen Way
Fort Washington, MD 20744
Reply With Quote
  #8  
Unread 12-21-21, 07:47 AM
Joes Joes is offline
Registered User
 
Join Date: Dec 2021
Location: Abingdon, VA
Posts: 7
Joes is on a distinguished road
Gentlemen, this information is extremely helpful. Again Thanks, Joe
Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 04:25 AM.


Powered by vBulletin® Version 3.6.9
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.