Exhaust slip joint lube

[Greg Ellis]

I have a 63 C model with an O-360-A1D.  What is the lubricant of choice for the slip joint between the exhaust down tube and the rest of the exhaust?  I have heard people use mouse milk but McFarlane makes their DAM exhaust lube as well.  Is there a preferred lube for this?  Thank you.

[Fly Boomer]

2 hours ago, Greg Ellis said:

I have a 63 C model with an O-360-A1D.  What is the lubricant of choice for the slip joint between the exhaust down tube and the rest of the exhaust?  I have heard people use mouse milk but McFarlane makes their DAM exhaust lube as well.  Is there a preferred lube for this?  Thank you.

Mouse Milk is the only thing I have ever heard of for exhaust parts that are supposed to move.  RAM recommends it on all the joints, wastegate, and actuator every 50 hours.  The only exception is that, for a turbo, RAM recommends filling it with Berryman's B12 Chemtool and letting it soak for 24 hours to dissolve the gunk.

[Jsno]

I use nickel anti seize.

[N201MKTurbo]

I use aluminum anti seize. It seems to work well.

Also, before I assemble them I polish them with 400 sand paper to get all the corrosion and deposits off till they slide easily, then coat both surfaces with anti seize and make sure they slide even easier, because the anti seize lubes them. The anti seize seems to make a bit of a seal to keep deposits from forming in the joint.

[Bunti]

2 hours ago, bluehighwayflyer said:

PowerFlow recommends the use of a high temperature anti seize (MIL-A-907E or equivalent), but I use Mouse Milk every 25 to 30 hours when I change the oil.  16 years and no cracks so far.  

Do you have the PowerFlow installed? Do you remove the whole exhaust for the lubrication with Mouse Milk?  Or is there a better (less time consuming) way to perform the lubrication?

I am just asking because I also have the PowerFlow installed. I am looking for any suggestions to keep it in good shape.

Thanks.

[Pinecone]

1 hour ago, N201MKTurbo said:

I use aluminum anti seize. It seems to work well.

Also, before I assemble them I polish them with 400 sand paper to get all the corrosion and deposits off till they slide easily, then coat both surfaces with anti seize and make sure they slide even easier, because the anti seize lubes them. The anti seize seems to make a bit of a seal to keep deposits from forming in the joint.

I would like that aluminum anti seize would burn off quickly.  I would use Copper or Nickel.

Checking, it says up to 1600, but I seem to remember it used to be lower.  Nickel is good to 2400.

[PT20J]

Probably anything is OK as long as it doesn't contain graphite which will weaken stainless -- the reason never to mark on the exhaust parts with a pencil.

I have used copper anti-seize on the tail pipe ball joint. I have always used Aerokroil on the slip joints because that's what my IA likes. But frankly, I suspect that any of the penetrating oils will burn off quickly. 

My IA got a sample of DAM Exhaust Lube at the McFarlane booth at a trade show and I gave it a try this year. It penetrated the joint easily and seems like it would have some staying power.

https://www.mcfarlaneaviation.com/products/category/exhaust-dam-exhaust-lube/description/

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[N201MKTurbo]

45 minutes ago, Pinecone said:

I would like that aluminum anti seize would burn off quickly.  I would use Copper or Nickel.

Checking, it says up to 1600, but I seem to remember it used to be lower.  Nickel is good to 2400.

I’ve been using it for years (Permatex anti seize). The joints are slipping because you can see a shiny ring where the joints come together, and they always come apart easily. I don’t run my TIT above 1550, so they haven’t seen 1600.

[Fritz1]

almost any high temp lube that does not contain graphite is better than no lube, I use Mousemilk with a small brush every 25h oil change, the worst thing for a slip joint are repeated ground runs where the exhaust does not reach operating temperature, the slip joints do not slip and the exhaust develops cracks, when I am not travelling I do a 45 min test flight every two weeks