Muffler slip joint and bell joint assembly?

[Gary0747]

Are you supposed to use never-seize lube on the joints when putting stainless muffler connectons together?  I wonder if copper or alluminum based never-seize lube will surface alloy with the muffler at high temperatures degrading the metal?  Maybe best to assemble joints dry with no never-seize?

 

[Bart Chilcott]

I just attended Don Maxwell's Mooney maintenance training in Texas and we covered this topic.  He showed us how if the joints aren't lubed, the tubes will become dented from not being able to move.  He recommends a lubricating/penetrating oil called "Mouse Milk" on the joints.  

[jetdriven]

Does this apply to the ball socket where the tail pipe attaches to the muffler?

[N201MKTurbo]

I always use aluminum based anti-seize on slip joints. It makes them actually slip and you can disassemble them later. I've never seen any ill effects from the compound. I have seen ill effects from not using it.

The ball joints don't need it.

[Bob_Belville]

PowerFlowSystems: 

All slip joints must be disassembled and lubricated with a high-temperature anti-seize compound (MIL-A-907E or equivalent) at 500hr or Annual intervals (whichever comes first). While disassembled, inspect for wear or galling. This should be performed more frequently if headers seize between inspections.

[Shrobby]

Here is what Don Maxwell talked about..

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[Shrobby]

Call him and buy some!!

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[Shrobby]

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[Yetti]

So once assembled with Mouse milk.   Should you continue to apply at some interval?

[cctsurf]

1 hour ago, Yetti said:

So once assembled with Mouse milk.   Should you continue to apply at some interval?

Those who were just at the seminar can correct me, but I was told Essentially every time you open the cowl.  Just a little.

[Gary0747]

Mouse milk is a common hydrocarbon based penetrating oil. I would think it will cook away at high temperature and not leave anything behind like the aluminum and copper based anti sieze compounds.    I would think Mooney would give instructions on what to use in their manual, but I have never seen any. 

Edited May 28, 2016 by Gary0747

[jetdriven]

Mouse milk is good for penetrating and helping get them apart but perhaps a copper based paste antiaircraft would be best for assembly 

[Guest]

I use some form of anti seize any time the pipes are apart, on slip joints and ball joints.  In between I douce them with Mouse milk, seized pipes crack and break, free ones don't.

Here's what Ram Aircraft recommends,

http://www.ramaircraft.com/Maintenance-Tips/Sealless-Exhaust-Slip-Joints.htm

Clarence

[Gary0747]

This Ram recommendation makes the most sense to me. They are recommending a Nickel based anti seize paste. This is more expensive than copper and aluminum based anti seize but does not run the risk of surface alloying a lesser metal and degrading the stainless.