Water Cooled Stuffing Box

[hanleyclifford]

I dont see an advantage here. i would think that there is always water at the packing, even at hull speed. So what would be the advantage of having the added fitting?

I could see if it was high speed, and the water was not getting to the stuffing box, and it was running hot. Is it running hot?

Why do you want the "added water"?

It isn't just about heat; it's also about flushing accumulated silt and grit out thru the cutless.

[ndutton]

I don't think there's a big concern over nobility. As far as I know, typical stuffing boxes are cast in garden variety bronze rather than silicon bronze so it and yellow brass should not be that far apart. Keep up on the zincs.

[hanleyclifford]

Another Hole in the Boat

...but if you're worried about that, use a surfboard. 1/8" NPT barb ready for cooling hose (may incorporate some kind of shutoff). Inside was honed with ordinary brake wheel cylinder tool. Note what I can get away with when the wife is off island.

[sastanley]

I don't think there's a big concern over nobility. As far as I know, typical stuffing boxes are cast in garden variety bronze rather than silicon bronze so it and yellow brass should not be that far apart. Keep up on the zincs.

All the "bronze" in my Buck Algonquin stuffing box turned a very heavy green after the first year. So I agree with Neil...they seem to be the best supplier of these types of units but they still turn...so I don't think tapping something into the BA unit is any real issue.

Neil turned me on to Noalox...I've used it extensively, and just today I had some with me at the top of my friend's stick when installing a new anchor light...I used it on both the ss screws into the alum mast, and on the ss screws into copper Aqua Signal fittings. I've had good luck with it so far.

Incidentally, this is the buddy that dives on my boat...he dives to clean the prop...I go up the stick for him. good trade-off!

Hanley, someone in this thread mentioned high speed applications. I have friends with 'muscle boats'. I'd be happy to inquire if you'd like me to do so.

[ndutton]

My opinion is the benefit of this modification is to the cutless bearing. It works best with water flow rather than simple immersion in terms of temperature and longevity. Those of us with the bearing in a strut have flow with boat motion but those with full keels and the bearing in the deadwood have virtually no flow beyond the microscopic stuffing box drip.

Hanley's installation will provide significant flow through the bearing with modestly pressurized raw water introduced forward of the bearing. He'll have better bearing flow than us strut guys.

[Ball Racing]

Mine is not a sailboat, but my stern bearning- cutless holder has 2 ears-slots-scoops facing forward that provide water flow into the shaft area, and when underway pressurize both the cutless and the stuffing box.should be somewhat easy to mod a keel to acheive that if there is no bolt on stern bearing. Unless this is considered too much drag in the sailing condition.

[hanleyclifford]

Mine is not a sailboat, but my stern bearning- cutless holder has 2 ears-slots-scoops facing forward that provide water flow into the shaft area, and when underway pressurize both the cutless and the stuffing box.should be somewhat easy to mod a keel to acheive that if there is no bolt on stern bearing. Unless this is considered too much drag in the sailing condition.

Could you post a picture of that arrangement?

[hanleyclifford]

Realizing I had made another hole in the boat I thought it prudent to add a shutoff valve. This installation carries the same risk as a below water line cockpit scupper. Even so, the supply hose will rise to the underside of the cockpit deck (about 4 to 5 inches above the water line) before running horizontally to the raw water injection point.

[ndutton]

In addition, the anti siphon valve is now critical.

[hanleyclifford]

In addition, the anti siphon valve is now critical.

This is where it gets interesting. I have never had an anti syphon valve on Destiny even though I inject to the hot section right at the water line. One of my protocols is closing the raw water intake thru hull [B][I]every time the engine is shut down.[I][B]. That said, I have occasionally left it open at a fuel dock and observed no problems. I believe this is because the raw water supply hose rises above the water line before going to the injection fitting thus creating an air space as the residual water drains to the water lift at engine shut down. For syphoning to take place there must be continuous liquid in a line which opens up below the water line. I would entertain comments/criticism on this "line" of thinking.

[ndutton]

My general feeling on the subject is the same as bullet proof vests. Sure, they're uncomfortable, bulky and hot and for the vast majority of the time serve no useful function but when that once in a lifetime incident occurs you're glad you have it.

Counting on air in the upper section of the hose to prevent a siphon is risky. Water passing downhill through the hose - if of sufficient volume to fill the cross section - can draw enough vacuum to pull water in behind it and the siphon is started. This is not in every case, there are a variety of conditions that must be present but still there's a chance. That's the charm and bane of siphons, the ability of liquids to naturally run uphill in a portion of the system and never stop on their own once they're started.

As you know, that's what anti siphons do - break the vacuum caused by the scenario described above. Are you prepared to crawl behind the engine every time you shut down to close the shaft valve too?

[JOHN COOKSON]

For syphoning to take place there must be continuous liquid in a line which opens up below the water line. I would entertain comments/criticism on this "line" of thinking.

Hanley - I'm not sure I understand your plumbing but I do have this to offer for your consideration:
As a warm engine located below the "pool" of water cools it could possibly create enough of a vacuum to to start a siphon even with a bubble(s) in the line.

TRUE GRIT

[hanleyclifford]

Back to the Drawing Board

Winter has a way of making us second guess ourselves and so when Neil made the comment about cleaning up the inside of the packing gland shaft after threading in the close nipple for the water injection I realized what a small clearance existed to the shaft and thus how little water I was going to inject into that log. So...scrap all the above. This is the new (water) dispensation as I see it. A few bugs still need to be worked out, like - how worried should I be about the hole that had to be drilled into the deadwood to bring in the (now) 1/4" nipple? Should I fill with epoxy (thus creating a tough repair for the next guy?) or be content with a wood, mechanical collar on the deadwood?

[ndutton]

The tight clearance you observed is all the more reason this cutlass 'irrigation' system is a positive. While considering the flow you'll have when it's done, think about what it has been in the past with only simple immersion.

I see the fact you're thinking about it and analyzing your installation as a great thing.

edit:
Y'know, Buck Algonquin already manufactures a product ready made for this application:

http://catalog.buckalgonquin.com/viewitems/packing-boxes-w-spud/water-cooled-packing-boxes-self-aligning-spud-type?

[hanleyclifford]

Neil - I did look thru the Buck Algonquin catalogue and that unit you referenced is a beauty but they don't get down to my size (1" shaft").