Leaking stuffing boxes.

Trying to decide if I need to stop for maintenance on our trip north or if I can take care of this myself. The stuffing boxes on our DF 44 are leaking pretty badly at rest or underway. Until now, the bilge pump system the PO rigged up had been handling the 1 gallon or so of leakage we were seeing every 2 hours. But the pump, or it's circuit, has failed. (I posted about this in the electrical section). Now we're having to empty the collection basin every 3 hours or so with a bucket. I tightened the port stuffing box (they're the kind with two bolts that draw one section into the other) and it slowed the leak a bit, but I was leery of going too tight. I took the temps on both boxes underway today and both were in the 114 -119 range.

Should I tighten them further to try to stop the leakage and continue to monitor the temps or take a day off our trip and take it to a pro?

angus99 said:

. . . take a day off our trip and take it to a pro?

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I can just say that if it were me, that is the route I would take. Water coming in and bilge pump has problems? A no-brainer, in my humble opinion.

It's a convoluted, almost bizarre, system. See if you can envision: The stuffing boxes drip into pans beneath the shafts at the rear of the engine room. Hoses carry the collected water forward to the sump in the front of the ER where bilge water would normally collect. Two bilge pumps are in this forward bilge sump. The smaller of the two is a sensor type that comes on with a half inch of water or so and sends it AFT (!) to a 3-gallon tub. This tub collects drippings from other areas of the boat and a bilge pump inside it pumps it all overboard. This last pump is what has failed in this Rube Goldberg system--which has actually worked beautifully up to now.

Two updates: If I shut down the small sensor-triggered pump forward, it will stop sending water to the tub aft where the out-of-commission pump is located. The large forward pump is still there and could easily handle and water that collects in the sump. it just triggers at a higher level.

Secondly, my son reports that the drips from the stuffing boxes may be slowing on their own. Only an inch of water last time we checked!

Angus, it does not sound like you are too familiar with stuffing boxes or packing. Just randomly tightening to stop excessive leaking could cost you a shaft and potentially a boat. I strongly suggest you bite the bullet and have a pro examine and probably re-pack the boxes.

As long as it is just warm to the touch, you should be able to continue to tighten it till you get a couple of drips/minute.

meridian said:

As long as it is just warm to the touch, you should be able to continue to tighten it till you get a couple of drips/minute.

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Thanks, guys. That's how I did it on my sailboat. Now I'm using an IR thermometer to test out the temps. There was no change in the temp when I tightened them previously. But these are larger and have a different tightening system. I think I'll let them weep and continue to monitor.

Tighten it a little at a time while monitoring it's temp.

Angus99' I have a boat very similar to yours.

You can call and discuss your shaft seals and pump system if you want to.

336-710-2188
Shay

I'd guess you probably have enough room in the stuffing box to add a couple rounds of new material to help you get by for a while...I'd use Gore. And if you have good access, a complete in-water repack isn't exactly rocket science. You'll need the "cork screw" tool to pull the old segments, and would want the new pieces cut to size and ready to slap in place. Knowing how many wraps are currently in there would be useful info...

sounds like the PO wanted a dry bilge so he added small sumps. I wish boat makers would design bilges with small sumps.

At this point you sound over your head. I strongly suggest stopping at a good yard and getting them packed correctly before you mess up the shaft. Once they start leaking to that level tightening usually doesn't doo much. Adding a ring might help but why not do it right?

You probably will pay to have it done at home so why wait?

I think if it was me and I was in your situation I'd stop at the nearest yard that can check and repack your shafts as needed. I wouldn't wait too long a scored shaft will cause you long term problems. Too much water intake could potentially sink the boat.
I know I'm talking extremes but why wait until you have an extreme situation?
Bill

Time to repack the shafts.

Angus: I just went through the stuffing box issue, see "Stuffing Box Re-packed" in the General Maintenance section which has recent posts. I suggest that you get some help from a pro if you have never done this job. The guys here were a big help and it's not all that complicated once you see how it's done, plus an extra set of professional hands is well worth the cost.

I appreciate all the advice, guys (Shay, thanks for the number; I'll definitely give you a call).

When we started feeling a little vibration yesterday, we stopped at the Hinkley yard in Thunderbolt, GA. They found a couple of microscopic dents in the starboard prop but, more significantly, the line cutter was damaged and part of it was free-wheeling around the shaft. While it's out of the water, they'll do the stuffing boxes.

For the record, I repacked the stuffing box on our sailboat a few times over the years, and understand their function. But these are designed differently and I'm extremely cautious when confronted with anything new.

The source of the starboard stuffing box leak has been found. The large bronze casting at the shaft log, through which the shaft passes, is misaligned. The misalignment means that the gap around the shaft is very visibly asymmetrical and packing can't possibly keep the water out. Now, the question is why is it asymmetrical. One possible reason: on our first night out, we fouled the starboard prop with a mooring pennant. (I'll post more on that eventually) Had to get a diver to get us off the next morning. That for sure broke the line cutter and may have been the source of the misalignment.

The shaft may be bent. Rotate it and see what's up. The brass part is usually soft mounted to the hull so it may be the engine is misaligned. Even engine mounts can be broken. Wrapping the rode can cause some bad stuff.

IMO you need a yards help.

bayview said:

The shaft may be bent. Rotate it and see what's up. Even engine mounts can be broken. Wrapping the rode can cause some bad stuff.

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Thanks. The shaft is fine, luckily. It's in a very competent yard and they're checking it with a dial indicator. I was at idle speed when it was wrapped, thank goodness.

Jay Leonard posted a warning last year about catching lines and breaking motor mounts...I don't remember much more than that as I'm familiar with the pieces and parts and damage....

Might take a better look around the engine room and or PM Jay for any specifics.

angus99 said:

The source of the starboard stuffing box leak has been found. The large bronze casting at the shaft log, through which the shaft passes, is misaligned. The misalignment means that the gap around the shaft is very visibly asymmetrical and packing can't possibly keep the water out. Now, the question is why is it asymmetrical. One possible reason: on our first night out, we fouled the starboard prop with a mooring pennant. (I'll post more on that eventually) Had to get a diver to get us off the next morning. That for sure broke the line cutter and may have been the source of the misalignment.

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Hmmm...the stuffing box floats on a rubber hose that is normally attached to the hull. If the hose has come askew you should be able to line it up easily. Since the box floats around the shaft the alignment doesn't have to be perfect.

Or are you saying the shaft is misaligned at the bearing in the shaft log?

Capt.Bill11 said:

Hmmm...the stuffing box floats on a rubber hose that is normally attached to the hull. If the hose has come askew you should be able to line it up easily. Since the box floats around the shaft the alignment doesn't have to be perfect.

Or are you saying the shaft is misaligned at the bearing in the shaft log?

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I'm saying it looks like this . . .



. . . very unlike the conventional stuffing box/shaft log with hose and collar I'm used to. (this photo is not my stuffing box.)

The misalignment is between the shaft and the large bronze housing that is bolted to the hull. Neither piece appears to be able to float in any direction.

the picture looks normal except for what's out to the left.

normally it would fit into a rubber tube...if it's bolted to the hull...it is unusual but not out of the question.

the whole point of having some flex in the assembly is to get the packing as square to the shaft as possible to prevent unusual wear...but if everything is aligned...again...not out of the question.

That is the style stuffing boxes I had on my boat. They are not that uncommon. The box that holds the stuffing is attached to a piece of hose correct?

Based on that photo I don't see any real misalignment. Looks pretty normal to me but that could be the angle of the picture.

Because the box is attached to a hose it is not uncommon for the box to sag when the packing sleeve is backed off and the stuffing removed. You just repack it and lift it up a bit if need be while you slip the packing sleeve back on. This centers it all again. You could loosen the large hose holding the box if need be to adjust out some of the droop if you want.

The box and shaft need a good cleaning and rust removal though. Some acid and a wire brush scrubbing would be a good start. If the shaft is worn down where the packing rides on it you can slide the box off the hose, cut the hose back and slide the box back onto the hose so the packing rides on a unworn area of the shaft.

I just caught the part where that is NOT a picture of you actual stuffing box.

So based on that photo what is different about your box to shaft alignment?

Capt.Bill11 said:

I just caught the part where that is NOT a picture of you actual stuffing box.

So based on that photo what is different about your box to shaft alignment?

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Found a shot of our port stuffing box. Hard to see, but the aft fitting is bolted to the hull in four places. Other Defever owners have told me theirs are similarly built and have the same rough, unfinished appearance where attached to the boat.



I only had time for a short look at it partially disassembled while the mechanics were in there, but there does not appear to be anything attached to hose as you're describing and as I'm familiar with. The shaft appears to the naked eye to be significantly off-center . . . maybe up to 1/4" . . . where it passes through the bronze casting that's bolted to the hull. One mechanic said the packing was so tight on the constricted side he broke a tool trying to extract it. The boatyard will be taking measurements and discussing how best to modify it.

One possibility, strictly off the top of my head: one of the previous owners installed a Twin Disc to replace a Velvet Drive on the starboard side. That affects the engine/shaft geometry and requires motor mount adjustments. It will be interesting to see what the measurements say.

Well, now I get it. I don't see what the point was in hard mounting the box like that and not attaching it to a hose where it can float on the shaft and vastly lessen the effects of any shaft misalignment on the packing and box. Seems kind of stupid to me.

If you are a 1/4" off in the alignment through the box you definitely have some kind of problem. I guess you need to start with uncoupling the shaft from the transmission and see if that changes the alignment. If it doesn't, then it's on to pulling the shaft and checking for straightness, target wiring or laser alignment of the struts, box, engine and so forth.

Single strut or V. Your shaft is probably misaligned if its not centered in the shaft log. Rubber hose shaft logs are more forgiving.

Just a thought. If it was fine before, then you picked up a line, and that line was apparently enough to break the line cutter, then would it be at all possible it moved the engine alignment? Seems if your shaft log didn't move, and your stuffing box is bolted to the hull, the only moveable part is the motor mounts. Just a thought...
Jeff

Good thought, Jeff. (It was actually 2 set screws on a limiting bracket on the line cutter that sheared, so the force was apparently not too excessive. The diver was able to unwind the pendant by hand in less than a minute, so it was not tightly wrapped. The shaft has now been dial-indicated, and is true.)

Turns out the lead mechanic told me yesterday that the female side of the stuffing box was apparently installed slightly misaligned by the factory (!). He said it's been working reasonably well all these years with no evidence of shaft wear. The packing was asymmetrical and pretty well shot; hence the excessive leaking. They're quoting 10-12 hours of labor, plus parts, to reinstall the stuffing box properly.

I want to have this done, but would prefer to pick my own expert when I get the boat to the Chesapeake with someone experienced and highly recommended. The Hinkley yard in Savannah, where the boat is now, has a good reputation but I don't think they have experience with this particular issue. The mechanic says he can manipulate the packing to minimize the leak to almost a normal drip level, get normal function out of it and no risk to the shaft if I want press on as is.

On the other hand, it would be nice to have this resolved. What would y'all do?

If it were me, I would surmise that if it were installed within the flax's ability to seal properly that having it aligned more perfectly is not of significant value.

That design requires a bit better engine alignment than the hardwall rubber hose set up, but has advantages of not ever being able to twist a hose if it gets too tight or over heated. Boats have sank over failed stuffing box hoses but your design seems like it would eliminate a leak large enough to challenge a bilge pump, even if it somehow lost all it's packing. The only downside is it is less tolerant of absorbing hull flex but the boat is likely a rock and not an issue.

Adequately aligned and sealed is " sealed " I would not spend extra to make it more perfect than the boat builder considered acceptable.

Being a re-formed perfectionist, I can tell you there is room in the world for less than perfection or we would not need stuffing boxes to start with.

" My Opinion "

1. Not sure you'll find anyone that is more "expert" in the task at hand...it's just not that complicated.

2. Doug Doty has a point that a softer packing may be all that's needed. I might try a ring or two of this stuff to make up for any asymmetry...

WESTERN PACIFIC TRADING Drip-Less Moldable Packing | West Marine