Firewall Crack(s)

[N6752U]

I just heard from my mechanic who tells me that he has found several cracks in the firewall (same mechanic for several years, not sure why he only found the cracks now). He is telling me 4-7K to patch and up to 14K to replace!! This all seems pretty steep to me, has anyone had a similar problem and if so what did you do to resolve the issue? Additionally is there a recommended procedure to patch the cracks? 

[MooneyMitch]

Hi 6752U.

This sounds very interesting!  I might suggest you speak with Paul Lowen from LASAR, or Don Maxwell at Maxwell Aviation, or Tom Rouch at Top Gun Aviation.  Collectively, they have probably seen more Mooneys than anyone and may be able to provide some very valuable information on this subject.

 Out of extreme curiosity, please give us some specific details and/or photos.

[sellis]

The firewall can be patched using .016 SS321 AMS5510 stainless steel sheet metal. The crack will need to be stop drilled. The patch needs to be installed using CS-3204-B2 sealer and stainless steel rivets.

[MooneyMitch]

Thank you Stacey.  I had never heard of or seen firewall cracks before.   Is this something that may appear from an existing penetration?

[N6752U]

Do the rivets need to be a solid (bucked / driven type) or can they be a structural pull type (pop rivet) that retains it's stem?

[tony]

Stacey, thank you so much for continuing to monitor this board, especially in this difficult time.  I myself have lived through a plant closing and I understand the environment that you find yourself in.   I really think that it’s awesome that you continue to provide the current owners support like you do. Best Wish and have a happy holiday

[bjmacdonald]

I too have had a few cracks in the fire wall of my C model down around the bottom of the foot wells. they were stop drilled and patched i was told that this is a common issue on early mooneys from a very well respected IA.

[DaV8or]

Quote: tony

Stacey, thank you so much for continuing to monitor this board, especially in this difficult time.  I myself have lived through a plant closing and I understand the environment that you find yourself in.   I really think that it’s awesome that you continue to provide the current owners support like you do. Best Wish and have a happy holiday

[jbreda]

For what it is worth - I have a used firewall that you could cut sections from and used as a doubler/patch if that seems appropriate.

John Breda