"Dripless" braided/moldable gland packing

[GordMay]

Is there such a thing?

Don Casey on “Drip-Less Packing”
"... An alternative to conventional braided packing is Drip-Less moldable packing. The advantage of this type of packing is that it is self lubricating, which eliminates the necessity of letting the stuffing box drip. Drip-Less packing requires two retainer rings of conventional packing. You install a ring of conventional packing, then push Dripless Packing into the box until it is about three-quarters full. A second ring of conventional packing completes the job. Tighten the nut just enough to stop the box from dripping. This type of packing runs hotter than water-lubricated flax, and over tightening will generate excessive heat. The stuffing box should not be too hot to touch. Low-friction packing is six to ten times more expensive than flax, but because it rarely needs adjustment, it can be a good choice for a stuffing box that is particularly difficult to service."
➥ Servicing Your Stuffing Box by Don Casey

GFO® fiber dripless packing instructions state, in part:
“... Install GFO fiber packing in the stuffing box one ring at a time making sure that you stagger the joints approximately 90o. It is essential that the ends of the rings meet cleanly at the joint. (Do not add grease or other lubricants - these can hinder performance.)
Tighten the packing gland until it is snug. Do not over tighten.
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.) ...”
➥ http://www.gfopacking.com/

See also Main Sail’s “Re-Packing A Traditional Stuffing Box”
➥ Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine at pbase.com

[Maine Sail]

With a good friend who is a shafting shop owner, and specific conversations with Durmax, eMarine & W.L. Gore I would have to say no it is not drip free unless the box is specifically designed as such.

The folks at eMarine have told customers "dripless" is okay provided the temp does not exceed 130F and they have also told customers that it must drip some but less than conventional. Their tech support is less than consistent but their printed directions DO NOT say it is drip free. "Adjust for minimal leakage" is a lot different than "adjust until completely dry". I don't know how to measure a term such as "virtually" but I do know that "virtual" and real are not the same thing. "Virtually no leakage" and "no leakage" are vastly different. It is therefore hard to quantify "virtually" except to say the marketing team and lawyers are in cahoots. The lawyers are protected by the word "virtually" and the marketing team makes owners think they can run with no leakage and sells the product..

Drip free adjustments completely ignore the stagnation caused by a non-dripping seal and SS crevice corrosion. Most dripless shaft seals like the PSS are now vented/plumbed and allow fresh oxygenated water at the shaft up in the log.

My buddy Dick is seeing a lot more shafts suffering crevice corrosion up in the shaft log and the suspicion is that it is due to the lack of fresh oxygenated water moving through the shaft log by owners pinching it off at the stuffing box. I have also seen shafting that was badly grooved using drips-less packing as "dripless", despite the manufacturers claims that this can't happen. There is a difference between drip-less (drips less), and dripless (completely dry)..

Rich L. at Duramax, the makers of Ultra-X Packing (same basic stuff as GFO just a LOT less expensive), specifically says; "Ultra-X is absolutely NOT drip free, but IS drips less than conventional flax packing, because it is more thermally conductive and can survive with less drips per minute than flax."

Straight from the manufacturers mouth "absolutely not drip free"...

[Mark Johnson]

Originally Posted by Maine Sail

With a good friend who is a shafting shop owner, and specific conversations with Durmax, eMarine & W.L. Gore I would have to say no it is not drip free unless the box is specifically designed as such.

The folks at eMarine have told customers "dripless" is okay provided the temp does not exceed 130F and they have also told customers that it must drip some but less than conventional. Their tech support is less than consistent but their printed directions DO NOT say it is drip free. "Adjust for minimal leakage" is a lot different than "adjust until completely dry". I don't know how to measure a term such as "virtually" but I do know that "virtual" and real are not the same thing. "Virtually no leakage" and "no leakage" are vastly different. It is therefore hard to quantify "virtually" except to say the marketing team and lawyers are in cahoots. The lawyers are protected by the word "virtually" and the marketing team makes owners think they can run with no leakage and sells the product..

Drip free adjustments completely ignore the stagnation caused by a non-dripping seal and SS crevice corrosion. Most dripless shaft seals like the PSS are now vented/plumbed and allow fresh oxygenated water at the shaft up in the log.

My buddy Dick is seeing a lot more shafts suffering crevice corrosion up in the shaft log and the suspicion is that it is due to the lack of fresh oxygenated water moving through the shaft log by owners pinching it off at the stuffing box. I have also seen shafting that was badly grooved using drips-less packing as "dripless", despite the manufacturers claims that this can't happen. There is a difference between drip-less (drips less), and dripless (completely dry)..

Rich L. at Duramax, the makers of Ultra-X Packing (same basic stuff as GFO just a LOT less expensive), specifically says; "Ultra-X is absolutely NOT drip free, but IS drips less than conventional flax packing, because it is more thermally conductive and can survive with less drips per minute than flax."

Straight from the manufacturers mouth "absolutely not drip free"...

I have a client that had me check out his new stuffing box, that was packed with the new "Gore" packing. These products are new to me. In about 10 minutes of continuous running at the dock, in gear... @ about 2000 RPM, it stayed cool and didn't pass a single drop. I thought great!

Is this too tight? How much dripping should it have?

Thanks, Mark

[s/v Thea]

I installed Dripless Moldable Packing, http://www.defender.com/product.jsp?...2328&id=569190 three seasons ago, when installed no drips and no heat. Last season was dripping slightly but overall I'm quite happy with it and will use it again this spring.

Doug

[Pete the Cat]

I used moldable dripless packing for at least 10 years and 300 hours of running with no scoring and no crevice corrosion. I would guess that many folks do not follow the directions (hand tighten, then 1/8th of a turn, run and repeat until no drips). Boatyards have used this stuff to remedy scored shafts from over tightened flax packing (sometimes it works if the grooves are not too bad) so I think that it has gotten a bad rap because most boatyards do not want to send the average boater away with a system they might have to thoughtfully adjust a few times when the boat is fresh from the yard in order to get it set. You cannot just honk it down and send folks on their way like you can with the mechanical PSS Seals. It certainly is possible to create heat, grooves and crevice corrosion with any compression sealing system if you overtighten it or do not periodically take a look at it. I repacked mine every 3 or 4 years.

The Gore stuff is not the same as other, cheaper black braided packing material according to other posters on other threads. My machinist friend who works for one of the most respected boatyards here in Maine swears by Gore material and says that most of the local lobstermen use it (he says they honk it down and do not have a problem, but I do not recomend that) and I have been using it for about 250 hours and it seems to run very cool with no leaks, no heat and no scoring. I used the same approach as the moldable in installing this. The folks where I buy the stuff (I buy it from are the designers and manufacturer of shaft and pump seals) are suppliers to the US Navy. My guess is they do not use PSS shaft seals on nuclear subs--and probably dripping is not a good idea either at their speed and depth. The guys were a bit coy about their relationship, but said that, "if it is good enough for nuclear subs, it will probably keep the water out of your boat".

After my experience as a delivery skipper with the kind of PSS Shaftseal problems others have mentioned, I would not have one on my boat, but I understand that many people seem to like them. They are heavily marketed and pushed by the boatyards for understandable reasons. They do not want the liability to send you away from the dock with something you might have to adjust a few times to get right.

No seal will work on an out of true shaft or fundamentally misalligned drive system.

To each his own. Maine Sail, my fellow Mainer, operates one of the best instructional sites on the internet for advice on boat maintenance. He just happens, IMHO, to be wrong on this one issue.

[Pete the Cat]

Note that is 3000 hours of running, not 300

[Catamount]

I am using GFO packing. The first go-round (2008), I think I had it tightened up way too tight, and seriously overheated the stuffing box. I didn't get around to changing the packing out until this winter, though. So it still worked after the overheating - it just required more frequent adjustment than I would have liked, and it was perhaps more difficult to get adjusted just right. I aim for no drips (at all) when the shaft is stationary, and just a very little weep when the shaft is turning. (drip - less)

I just recently pulled my shaft -- no scoring. The packing in the stuffing box nut looked like a solid mass of plastic, but in reality that was just on the surface, and when we pulled it out, the GFO packing was more or less in it's original condition.

[bstreep]

We put GFO into our stuffing box a couple of months ago. WAY less leakage and adjustment. I just can't do the "no drips" thing though - it's just one of those things that SHOULD drip...

Also did the rudder post shaft at the same time.