TheSamba.com :: View topic - Best Product to Seal and Lock a Leaking Oil Galley Plug?

Sat Jun 12, 2021 7:07 am

I've seen recommendations to use red thread lock, blue thread lock, RTV, and even JB Weld.

The high-temperature pipe thread sealant (white stuff) I used allowed the plug to start backing out and oil to leak past. Or maybe I just didn't tighten the plug enough?

Leaking plug (it has backed out from its initial position)

Sat Jun 12, 2021 8:04 am

We use this on all the machines at work for water and oil fittings, works great and it's non-hardening so you can remove the plugs at the next rebuild. From McMaster-Carr industrial supply

Reusable Non-Hardening Thread Sealants for Coarse Threads

Much thicker than sealants for fine threads, these sealants bridge the gaps between coarse threads. Threads coated with these sealants can be installed multiple times without recoating. They have low locking strength, so they prevent threads from loosening due to vibration and can be adjusted without tools. They meet NSF/ANSI 61 for use with drinking water.

Container
Max.
Pressure,
psi
Size,
oz. Type For
Fluids For
Gases Temp.
Range, °F For Max.
Thread Dia. Consistency Specifications
Met Choose a Color Each
Low Locking Strength
2 Brush-Top Bottle 10,000 300 -65° to 300° 4" Thick Liquid NSF/ANSI 61
Orange,White
4592K2 $28.14

Sat Jun 12, 2021 10:38 am

I can't imagine a properly tightened plug coming loose in this application. Too tight though and you could crack the case. If you use Loctite thread lock or thread sealant you need to have both surfaces totally clean for the Loctite thread sealant to be able to do its job.

Sat Jun 12, 2021 11:56 am

Wildthings wrote: I can't imagine a properly tightened plug coming loose in this application. Too tight though and you could crack the case. If you use Loctite thread lock or thread sealant you need to have both surfaces totally clean for the Loctite thread sealant to be able to do its job.

^^^^This....

And a suggestion......quit using PTFE (Teflon) based pipe thread sealants on "must stay in" items like galley plugs.

No matter what...Teflon is a LUBRICANT. As Wildthings noted....these are generally (but not always) tapered pipe plugs. If they are put in tight they should not move.

The simplest thing is to file a slight notch just on one area of the pipe plug. Then turn it in tight and with a punch...stake the case into the notch you filed. Done.

The only reason people use the non hardening pipe dopes...is because they are afraid of getting inside the case and in the bearings.

That is not a worry at all...if its properly applied. Just leave 1.0 to 1.5 complete threads on the inner end...with no sealant on them. If you applied the sealant sparing as you should...there is "0" chance of getting the sealant inside of the case. Ray

Sun Jun 13, 2021 2:57 am

I used aviation Permatex about 5 years ago on my gallery plug and it has worked fine. The engine was literally just rebuilt at the time and it would leak oil for about a minute on cold startups. I was concerned that maybe the threads had been torn up when it was assembled and were allowing oil to pass through. Has not been a problem since.