Stuffing Box, how often should it be changed

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Scott B

Scott B

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Sep 20, 2006
2,952
Hunter 33 Georgian Bay, Ontario, Canada
We're heading into our fourth season on our boat, with the engine at 400 hours, is it time to change the stuffing box or how often should it be changed. Last year it was still working well.

Right now its on the hard and will be splashing in a week or two so will be easy to change.
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
Scott, it's like reefing. And you don't have to be out of the water to do it.
 
A

alexco38

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Sep 25, 2008
1,096
CS 30 Toronto
Never if the rubber hose is still in good shape. It it drips too much, tighten the nut a little until it only drips when the shaft is turning. If you can't tighten it anymore, then just change the packing material.
 
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alexco38

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Sep 25, 2008
1,096
CS 30 Toronto
pretty cool to change the stuffing box in water

Not sure how you would do it in the water. I couldn't even image changing the packing in water.
 
zeehag

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
so it leaks a little---is doable in most boats in the water--or a helluva haulout for no good reason, but, if ye likes spending lotsa dough for not much reason, is allll goood.....is why god made bilge pumps..not much water gets inside the boat--make sure all yer toools and needs are ready before digging into the job--oh yes, and have the proper tools.....gooood luck....
 
Scott B

Scott B

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Sep 20, 2006
2,952
Hunter 33 Georgian Bay, Ontario, Canada
I know it can be done in the water...... but we spend so much time on the hard it might as well be done then. Once we hit the water, weekends are for sailing !!!! I don't have time for maintenance that could be done off-season.

I was interested in the approx. longevity of the materials. How often do you change the stuffing box, every 2-3 years, 5 years, 10? 200 hours, 400 hours 1,000 on the engine since sailing shouldn't wear out the packing or does time factor in as well???
 
Bob S

Bob S

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Sep 27, 2007
1,804
Beneteau 393 New Bedford, MA
Scott,
My boat is 15 years old with 350 hrs and I'm quite sure it has never been done. I also found myself having to adjust it a couple of times last season so i decide to do it. I wont be launching for another 2+ weeks. I was able to pull out 2 pieces of flax and judging from Mainsail's write up, I thought there would be three. They were very dry and quite thick. Looked like an old piece of hemp rope. I bought 3/16 GFO but now am thinking I need 1/4" but I'm not sure. I remember reading Hermit Scott struggling with size when he did his. It isn't that difficult to do so if you feel it's time just do it. It gives you a better understanding of your boat.

Bob
 
Chuckbear

Chuckbear

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Jan 3, 2009
821
Marine Trader 34 Where Ever I am
Scott, You change it when you can no longer adjust it to properly control the drip. Chuck
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Scott,

It's unlikely you need to change it yet but dry winter storage can exact a toll on them in terms of longevity in the form of rot. Especially If it was factory packed with natural flax. If it was done with a synthetic fiber they can last for a very long time. As Chuck said if you can still adjust it to your desired drip rate, without creating heat, you're fine.

All that being said it takes little time to do and is a good process to learn. Gore GFO or Duramax Ultra X is cheap and a superior packing to traditional plant based fiber packings. If you have the time give it a whirl then you'll know how easy it is...
 
Chris Burti

Chris Burti

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Dec 2, 2003
480
Catalina C-320 Washington, NC
If you you motor mostly in silted, sandy, muddy waters you might want to consider changing the packing every 200-400 hours. The fine paticulates in those waters will migrate into the packing, imbed themsleves there and ultimately score your shaft to some extent more or less depending on conditions.
 
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bffatcat

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Jun 8, 2004
853
Pearson 26W Marblehead
stuffing box

You said change the stuffing box right? Im sure you meant change the packing You never
have to change the gland itself. Though you might have to change the tubes if they go bad from age. Like the guys said just tighten it up until it drips about 1 drip a minute. And If you have to repack it I would do it on the hard and use new synthetic packing
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
Just gotta say, I still do not understand why people think they need to do this on the hard.

The flax material, as is the whole stuffing box, is a lubricant. The lubricant is water.

When you do it on the hard, you have NO way of knowing how tight it needs to be. So you end up putting your boat back in the water with either a too loose or too tight setting. Too loose? Not a problem, just tighten it up. Too tight? Backing off does NOT let the material expand, so you've wasted a perfectly good repacking for nothing, and should do it all over again.

And, if done on the hard, once you put it in the water you start the engine right away to get away from the dock to your slip or mooring. Thus, little or no time for the water to get to the box to lubricate it.

I had our boat out for two months one time, and had to replace the material 'cuz it all dried out. How'd I know? I went out for a little motor and checked it.

For those of you hauling regularly, it would seem that you should do this regularly, too, like, every time you put your boat back in the water, while it is IN the water. Your boat will not sink.
 
zeehag

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
OMG!!!!!! i actually AGREE with stu on something!!!!!!! WOW!!!!!!!
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
zeehag, sometimes we save the best for later. This is not the first time we've agreed, but we're having so much fun I'm not gonna try to figure out what it was! And I'm sure there are many more to come. Enjoy your voyage, you're input is priceless.
 
Warren Milberg

Warren Milberg

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Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
I think the issue of re-packing one's stuffing box while the boat is in the water or on the hard is a pretty individual one and that one size does not fit all. A lot depends on the configuration of your gland, how much room and/or trouble you have in unpacking the old gland properly, and the amount of clearance that exists between the shaft and the gland that will let water into your boat. Having recently repacked my conventional bronze gland with the boat on the hard I can say that (1) I had little space to work comfortably as the compression nut is very close to the coupler; (2) the old packing material was really difficult to remove and required the use of a number of tools, some on hand, some that I brought back to the boat the next day (boat tasks always result in not having all the right tools with you) ; and (3) my gland would have leaked a LOT if all this had been done with the boat in the water. I suppose I could have fabricated some temporary method to stop or reduce the amount of water inflow from an open gland by using rags, removable plumber's putty or some similar material. But the real issue is that unless you are VERY sure you are not going to have a problem controlling the amount of water coming into your boat, and that you can unpack and repack your gland quickly, why would you risk doing it in the water? If your boat is out anyway, what is the downside to doing this relatively easy task at your leisure with no pressure to hurry or worry?

Having said all this (phew....), I hand-tightened the gland once the new GFO material was properly cut and inserted into the compression nut. While I thought I had adequate friction (by feeling how the shaft turned by hand), the gland leaked more than I liked once the boat was in the water. But it was then a simple matter to turn the compression nut a few flats and bingo, no drip at all ...
 
sailingdog

sailingdog

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Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
Warren—

You do realize that a GFO packed stuffing box should drip a bit when the prop shaft is moving, right??
 
sailingdog

sailingdog

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Oct 22, 2008
3,502
- Telstar 28 Buzzards Bay
Yes, I know, so let me clarify

The trouble with making it completely dripless is that it is too easy to over-tighten the packing gland, and that is the most common error when using the GFO packing material. That can prevent enough water from getting in and lubricating the GFO, as it does require some water for lubrication. This can result in the shaft getting scored.

Unless you've had some experience with the GFO packing, I generally recommend that you let it drip a very tiny bit when the shaft is in motion, rather than risk over-tightening it.

If it drips a very tiny bit while the shaft is in motion, you can be pretty much assured that you haven't overtightened it. It shouldn't drip anywhere near as much as traditional packing gland though. :D


Bob S said:
Dan,

That is confusing because they advertise it as being dripless.

http://www.gfopacking.com/?gclid=CP32poyQiaECFctx5QodNw0xOA
Click to expand
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
gore -- dripLESS???

Interesting and a repeating point of conversation. I think all you have to do is read the linked page, and then the installation instructions, which state:

"After about one or two hours of running time, check the stuffing box for leakage, and make a final adjustment to attain minimum leakage. (There should be virtually no leakage.) "

That sure doesn't mean NONE to me. Never has.
 
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