I have seen numerous problems with the "Dripless Mouldable" stuff and even experienced it myself and have discontinued use and I will not install if for customers, even if they ask. The packings I install mostly these days are Duramax Ultra-X and Gore GFO. Gore has had some slight sizing issues in the past, slightly bigger than spec, but it is still great stuff. I dislike the Western Pacific Trading GTU stuff as the braid is different and it tends to unlay after being cut, I have stopped using it. Other than the braid WM offensively prices it @ $8.00 per foot and Hamilton retail is $3.00 per foot for Ultra-X.

The Duramax Ultra-X is sold by Hamilton Marine and is every bit as good as GFO in my experience with it and the braid looks to be identical and it cuts cleanly. Ultra-X is also a LOT less money than GFO or GTU. I just bought 4 feet of 1/4" last week for upcoming jobs and I think it cost me about $11.00..

Traditional boxes should drip some so they don't become an air trap, PSS learned this the hard way and now sells all their glands with an air vent or direct plumbed. If they accumulate enough air the mouldable stuff can get so hot it can melt out and plug the shaft log. Mine ran fine for about 100 hours use then all of a sudden, without notice, go so hot I blistered my fingers on the stuffing box when checking on the "smell". With the nut completely removed I barely had one drip per minute due to the green clay plugging the area between the shaft and stuffing box.

Making a shaft totally dripless not just drips-less can also lead to the potential for crevice corrosion of the shaft due to the stagnation of the seawater in the shaft log. A little movement helps keep the water in the shaft log fresh. GFO or Ultra-X can be set to drip very, very little but still run cool, at well under 100 degrees. On many boats the drips evaporate from engine heat before they even accumulate leaving just traces of salt behind.

Keep good zincs however because graphite is the most noble on the galvanic scale and the shaft and prop become "sacrificial" to these packings if you don't keep up with the zincs.