Amerind Mackissic Mighty Mac shredder air leak at muffler

[Actonite]

I have a Mighty Mac 14PT that works great. I only wish I ended up with more mulch after shredding a huge pile of branches. I recently noticed an air leak just below the muffler. Though I couldn't tell if it was leaking on the top or bottom of the pipe the muffler is attached to, I sense it was the top, as the pipe is frozen on the bottom. I was able to untwist the muffler from the top, after loosening the lock washer. I believe I should use something to keep the air from leaking through the threads. In my research, I have read that either copper or nickel anti-seize lubricant should be used on these threads. It doesn't look like anything was used before. I'm having a hard time choosing between the two. Which would you recommend for my shredder's muffler?
Mighty Mac 14PT

 

[oldballs]

I'd probably just ignore the leak, if it were me.
Cheers,
Mike

 

[tomplum]

I would probably use some furnace or exhaust cement type thing. Lots of vibration there.

 

[Actonite]

If I just leave it, the gases escaping out of that crack will eventually eat away at the pipe, and that will only lead to more headaches. I'd rather prevent the damage rather than just live with it.
As far as furnace or exhaust cement, that's what the anti-seize is for... unless you've used a particular product you can recommend.

 

[MAX-24-Dean]

Permatex muffler and tail pipe sealant works good to seal leaks. Amazon.com

 

[Actonite]

That Permatex product isn't ideal for my purpose, as I want to be able to unscrew the muffler in the future, if necessary. I'm still leaning toward the anti-seize, but I'd appreciate knowing people's experiences with both the copper and nickel, so I can choose between the two.

 

[MAX-24-Dean]

The nickel anti-seize has a higher temperature rating than the copper. I used the nickel as it was specified for bolts on steam/boiler repairs.
If it is exposed to the exhaust gases I am not sure what the results will be.

 

[Actonite]

I ordered some Loctite N-5000. I'll experiment with it and see if it works or gets blown out by the gases.