Stuffing box dry running, drips when engine is off?

[omac]

Hey Stuffing box experts,

My 84 CS 36T Stuffing box has a peculiar issue. There is a slow/steady drip when the engine isn't running, but during operation the stuffing box goes dry (all in slip testing). It runs cool, but this is not my understanding on how the Stuffing box is supposed to work.

Would anyone have some insight?

Thanks in advance,

Mac

 

[Davidasailor26]

Are you sure it’s dry when running? Sometimes the water gets thrown off the shaft in a bit of spray so it’s not as noticeable as a drip.

If that’s not the case I don’t have much explanation, other than to say if it’s cool when running you could try to tighten it a bit to reduce the at-rest dripping then check it again.

 

[jssailem]

with @Davidasailor26.
Best detailed description I have read is from @Maine Sail. Here is the link to his website. If you benefit from his info why not share the value of a sixpack to keep the site available.

Re-Packing A Traditional Stuffing Box - Marine How To

The Stuffing Box (click any image to see a larger version) While digging around in some old boat parts boxes I found a stuffing box from an older sailboat. I though it would be a good time to rig it up

marinehowto.com

 

[Ralph Johnstone]

This may be affected by how long it's been since the packing was changed and the type of packing which was used. You don't want to see the packing running dry UNLESS YOU KNOW EXACTLY WHAT'S GOING ON !

Here's a post I put up regarding running dry and it's not all that uncommon :

Do We Really Need to Leak .............

............. yes, for good health, about four to five times a day is good. However, for a number of years I have been chiming in here on packing glands leaking and the fact I have run mine bone dry almost from the day I bought the boat new in late 1998 as a '99 model H310. As mentioned in...

forums.sailboatowners.com

Maybe consider repacking so you know exactly where you're starting from.

 

[omac]

Thank you for the responses. I appreciate your insight and time.

It didn't leak before I changed engine mounts, where I slightly misalignment the shaft and it ran hot and started to leak. When I tightened it the water came out grey coloured. Which is leads me to think its packed with tefpack - a synthetic packing (referenced on main sail's article)

- David, pretty sure it runs dry as the "wet spot" evaporates as the shaft rotates.

- JS, I definitely follow @Maine Sail as he's a CS36T owner and the previous owner used his upgrades as a guide. His website is a wealth of knowledge and I buy his products where I can, especially the butyl tape!

- Ralph, thanks for the link to your detailed article and it makes a lot of sense. It's been about 10 years since a new shaft, cutlass bearing and packing was completed. The temperature runs cool about 20C, and builds slowly as the shaft rotates, up about 6-8 degrees over an hour. It was still cool to the touch. I think I will tighten slightly and monitor, and then plan to repack the gland so I know where things stand exactly. Your method of grease cotton string sounds perfect for an in-water change up!

Thank you again!

Best,

Mac