Thread in Sealant
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Thread in Sealant
I guess the saying "You're never too old to learn something" is a fact. Yesterday, while having my morning coffee and surfing different websites, I came across something that kind of stopped me.
Despite dozens of years and countless rebuilds of engines, transmissions, rear ends etc. as a hobbyist, I had NEVER seen or heard of putting a thread in the sealant of two flush mating surfaces (where no gasket is used) to prevent the sealant from completely squishing out. It is there to provide a minimum sealant thickness. I understand that Lycoming even stipulates its use in some of their aircraft engine rebuilds. As I said, despite thousands of hours of researching different procedures, I had never come across this. On its face though, it does make sense. It calls me to try it on my next FWD transmission. Any input - pro and con?
Despite dozens of years and countless rebuilds of engines, transmissions, rear ends etc. as a hobbyist, I had NEVER seen or heard of putting a thread in the sealant of two flush mating surfaces (where no gasket is used) to prevent the sealant from completely squishing out. It is there to provide a minimum sealant thickness. I understand that Lycoming even stipulates its use in some of their aircraft engine rebuilds. As I said, despite thousands of hours of researching different procedures, I had never come across this. On its face though, it does make sense. It calls me to try it on my next FWD transmission. Any input - pro and con?
Instructor
Joined: Dec 2012
Posts: 105
Likes: 15
From: Ball Ground Georgia
Using thread in this manner is standard practice in most aircraft piston engine case mating surfaces that don't use a gasket. The procedure is to use Aviation Permatex sealer, which is non-hardening, and running a silk thread around the mating surfaces. More recently, the use of Loctite 515 anaerobic sealer with no thread has become the preferred method, as it does a better job of sealing without any seepage or leaks. I am a licensed aircraft technician and I've done a few engine overhauls using the Loctite 515 and I've had no issues with seepage or leaks.
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Using thread in this manner is standard practice in most aircraft piston engine case mating surfaces that don't use a gasket. The procedure is to use Aviation Permatex sealer, which is non-hardening, and running a silk thread around the mating surfaces. More recently, the use of Loctite 515 anaerobic sealer with no thread has become the preferred method, as it does a better job of sealing without any seepage or leaks. I am a licensed aircraft technician and I've done a few engine overhauls using the Loctite 515 and I've had no issues with seepage or leaks.
Instructor
Joined: Dec 2012
Posts: 105
Likes: 15
From: Ball Ground Georgia
Permatex Aviation Grade 3D
and
#641543 Silk Thread
and
#646942 Gasket Maker
or
Loctite Gasket Eliminator
515 Sealant
For Distributor information call:
Permatex Customer Service @
Phone: 1-800-641-7376
May be purchased through
your local TCM Distributor
May be purchased through
your local TCM Distributor
For Distributor information call:
Loctite Customer Service @
Phone: 1-800-243-4874
Crankcase parting face, oil pump
covers,
This is copied out of the Continental overhaul manual. It's a very specific silk thread and Permatex. Honestly, you'd be far better off just using the Loctite.
and
#641543 Silk Thread
and
#646942 Gasket Maker
or
Loctite Gasket Eliminator
515 Sealant
For Distributor information call:
Permatex Customer Service @
Phone: 1-800-641-7376
May be purchased through
your local TCM Distributor
May be purchased through
your local TCM Distributor
For Distributor information call:
Loctite Customer Service @
Phone: 1-800-243-4874
Crankcase parting face, oil pump
covers,
This is copied out of the Continental overhaul manual. It's a very specific silk thread and Permatex. Honestly, you'd be far better off just using the Loctite.
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Instructor
Joined: Dec 2012
Posts: 105
Likes: 15
From: Ball Ground Georgia
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