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Stuffing box comparison

Do I Stay with the conventional stuffing box or go with a PSS or PYI Seal Installations?

Original Message:

I'm looking for opinions on which way to go on a stuffing box repack. The boat is on the hard for the winter and I am having the yard replace the cutlass bearing. I talked to the mechanic about installing a PSS seal while the drive shaft was out. He suggested that I stay with the regular flax packing. I guess I didn't explain to him HOW MUCH I HATE seawater in the bilge. I know I'm probably opening up a can of worms, but before they start the work I would love to hear from anyone with pro's and con's and your preference. Thanks in advance.

Baysalr, C-36, Deltaville,VA


"You have to decide whether you want a wet or dry bilge."

WET BILGE In salt water I personally can't understand why anyone would want that corrosive, smelly, slime producing stuff sloshing around in their bilge? Fresh water is different.

DRY BILGE The greatest advantage of a dry bilge is to be able to spot leaks. They can come from salt or fresh water - use the taste test. Once you've determined salt or fresh water you can start to the track the leak down. Another real help is which of the 4 compartments of the bilge is the water from the leak in? (i.e. a salt water leak from the stuffing box will first show up in the aft compartment. A salt water leak found in the aft center is probably from the back siphoning of the electric bilge pump exit if you have been heeled so that exit could be under water especially in a following sea). Another example for the MKIs with a keel-stepped mast, is rainwater wicking down the spinnaker halyard to the inside of the mast and then first into the aft center compartment. The leak potential is there - thru hulls, clamps, hoses, water tanks & on and on, but none are initially noticeable as a SMALL leak - with a wet bilge.

Ron Hill APACHE #788

Positive comments for PSS or PYI Seal Installations

We have a PSS Seal, and love it. Whatever you decide, the time to do it is while the shaft is out.

Tony Toskas, Winch Wench C-30 #2566

Go ahead and replace with the PSS shaft seal - you will love your dry bilge! As a matter of fact just do the installation yourself and tell the yardman to stand aside.

Max Munger

Check it out at: I installed the PSS Shaft Seal on my 320 2 years ago and my only lament is I didn't do it sooner! Bone dry it.

Orlando, cuba libre 2 C320 #112, Marina del Rey, CA

I have had the PSS seal for the last year and a half. Only way to go.

Mike Crosa, S/V Skeddadle, 1987 C30 TRBS #4877, Miami, FL

I have the PSS shaft seal and I believe that it is one of the best additions I made to the boat. It absolutely DOES NOT LEAK!!! Now if I had realized how much water the roller furling mast lets in, but that's another story!

Gary L. Harkins, Cygnus C400 #140 , Harbour Towne Yacht Club (Muskegon, Michigan)

Safety item to prevent stuffing box PSS seal or regular stuffing box nut: Place a clamp on shaft up against seal or nut to prevent the item from Backing off completely. If it should get loose the seepage would be Acceptable and the bilge pump could handle the seawater until you can safely make repair.

George Karda, C320 #641

On our last boat, a TMI (Chrysler) 30 I installed a shaft seal from PYI and it was the more water, PERIOD! In Sept. 99 we bought Wind Dancer, C320 #394 and I am thinking seriously of installing a PYI seal on it. The only thing you need to be careful of is that when you do your spring launch that you burp the air out so there water on the seal for cooling. This takes 1 second. Probably the best $200 I spent on the boat. Only wish I had done it years earlier.

R. Winkler, Milwaukee

Go with the PSS seal... I have it on my 27 for four years now and love it, don't have it on my 36 yet but will at next haul-out. Now the down side... Three years ago on a Sunday Morning in January, was motoring out of the marina and heard a loud BRRRRAP noise, shut engine down and started checking every thing, under, in, and around the boat for cause of noise, Found nothing. I restarted the engine and it ran fine, put it in gear and every thing seemed fine. We then hoisted the sails and shut the engine down. After a few minutes I turned the wheel over to a friend and went below to get our lunch. I noticed the carpet was wet and the bilge pump was running... and loosing the race... Shut all thru-hulls and the water was still coming in... I then started tracing the flow, back under the engine to the shaft. What I found was a bunch of wire and plastic (what was left of the bilge blower hose) wrapped around the shaft and PSS seal with a rather large flow of water pouring out of the mess. I grab the pliers and start cutting and pulling wire and plastic out to get to the source of the water. When I get through the mess I discover the rubber bellows of the PSS seal was ruptured. Stuffed rags in the shaft log to slow down the flow and sailed back to the marina and into my slip. The blower hose had somehow fallen and got caught on the spinning shaft. The BRRRRAP noise when it was pulled out. It then caught the hose clamp on the PSS bellows and caused it to spin with the shaft, twisting it into. Called PSS Monday morning and had a new PSS seal on Tuesday morning. My bilge has been dry for three years now. Go with the PSS seal...

Jim, C-27 Ambitious, Flowery Branch, Ga., C-36 Bonaventure, Brunswick, Ga

Positive comments for Staying with the conventional stuffing box

A lot of people really love the PSS dripless seal, but personally, I don't think dealing with a conventional stuffing box is all that big a deal. Once properly set up and adjusted, they're relatively maintenance free for a fairly long period of time, and don't really drip very much water at all. Back on my C34, I probably repacked the box every second season, and maybe adjusted it once or twice during the season. So far, on my C400, it's been two years since I've touched it. I'll probably repack it this spring, if for no other reason than to break away the corrosion on the nuts! As for the dry bilge thing, I'm not concerned about it. With a keel-stepped mast, more water probably enters via openings in the mast when raining (at the top, and also dripping in the halyard exits, etc) than will ever drip out the stuffing box. If your mast is deck stepped, maybe it's possible for the bilge to be utterly dry all the time... I honestly don't know. In my case, I'll hear the bilge pump operate perhaps once a day, two or three times if it's raining or windy. It's kind of reassuring, in a sense... if I had a dry bilge, I'd be dumping a bucket of water into it, once a month, just to make sure the pump was still functional!

Norm Bernstein, Amoreena C400 #105

I FULLY concur with Norm. I repacked my ancient A-4 shaft a few years back on my C-27 and have never had a problem with it since. I do check it out from time to time, but I never see more than a little dampness back there and only when we're motoring. It's bone dry at anchor. In fact, I like Norm's suggestion to repack it occasionally just to disturb the corrosion. Besides, the Braided Belgian Flax Packing instructions specifically state "Always allow some water to drip on to the packing while under way." They also warn AGAINST "overtightening." The stuff comes in 24" rolls and costs between $4 - $11 per roll depending on the diameter of the flax you'll need subsequent to consulting your Owner's Manual.

SL Collins

I was considering a PSS seal also but I stayed with the standard traditional approach. The determining factor was a packing material that I think I learned about from this list. It's made by the same company that makes gore-tex, the apparel liner. This material is much more durable than standard flax and has a greater heat tolerance. As a result, you can tighten down the box to make it virtually drip-free (The marketing materials say it is totally drip free but I have adjusted mine to allow a drop of water in every few minutes out of fear of scoring the prop shaft with too great a heat build up. I'm probably being overly cautious.) and the material is good for three seasons. I have had it in for two seasons and have not had to adjust it at all which suggests to me that it's holding up as promised. If you're interested, I'll dig out the info on the stuff and send it along.

Jim Overend, Carrie B C36 #769

Check out the dripless packing at West Marine (about $55 total). I put this in 2 years ago and not a drop of water since. It's a simple replacement for conventional flax packing and just as easy to install.

Lorne Hamilton C30 #2700 Lake Huron, Harrisville, MI

You can get the green Teflon flax stuff at west marine for about $50. You still need some regular flax also. Anyway this will last for several years and is also dripless. No hardware changes and much cheaper than 200.00 or so for a new dripless model.


I can confirm that on my C34. When I had the boat lifted out, I used a sponge to get all the water out of the bilge except for the last few drops. It was dry. Two weeks later, it was filled up to the height that the bilge pump drains it to -- that is, it took on enough water that the bilge pump dumped some of it overboard into the parking lot. Fortunately, I don't get real excited about the idea of a dry bilge, because dripless packing isn't going to help me get there. :)


I wouldn't get too concerned about the number of drips as long as it is reasonable-12 per minute or under. Even in my 1999 Catalina manual, in three different places it lists the number of drips per minute differently. The lowest listed was 1-2 per minute; the highest was 10 per minute if memory serves me correctly.

Tom Haevers, C-36 1733

If you run it hot and dry the stuffing will stick to the shaft when it stops. Next time the shaft turns it will tear pieces off the packing. Do this a few times and it will leak big time. The tighter you go the drippier it gets. Sound familiar? (Be nice).

Charlie Pearsall, Delirious

I was always told to let it drip when under power to cool the shaft but was never sure how much validity or importance to place on it? Anyway, I have the drip by default so I never worried too much about it.

Dan Wilcox, Blown Away 77' c30 ~ #773, Carolina Beach, NC

Something I haven't seen mentioned is that the packed stuffing box has to leak enough to lubricate the shaft/seal. It should not be hot to the touch after the prop has been turning for 15 minutes. I shoot for one drop every seven seconds WITH THE PROPELLOR TURNING. It might not drip at all when out-of-gear.

Charlie Pearsall, Delirious

I replaced the flax in my stuffing box last year for the first time since I had the boat. I attempted to get the nuts adjusted to have the required 4-10 drips per minute. Sometimes it would drip, others times it didn't. I'd get it adjusted right in forward only to have the number of drips change after putting the engine in reverse. Seems like every time we motored, either my wife or kids were at the wheel while I had my head stuck in the engine compartment. Am I being anal-retentive or is "close enough" the rule of thumb here. Besides, after getting this right, I'll figure out something else to worry about on the boat. As a side, I never did get the thrill of a dry bilge. I always figured they were made to hold water so then damn-it, mines gonna have water in it. :)

John Wamboldt, ZuZu's Petals C27 #6287,Lake Michigan

We now have dust in our bilge normally. It doubles as our shower sump so it gets cleaned once in a while. It took a couple of years to get her this tight. She had three leaks no one could find when she was new. Now it's very reassuring to check the bilge and find dust. It's a very positive indicator that all's well. Otherwise, I guess I'd have to put a cycle counter on my bilge pump to have the same level of confidence. We actually put in the drip less packing to prove the other leaks were there. I did still have to trace them myself. Amazing what you can do with water-soluble markers or dry cleanser trails to back track a drip. One hard lesson was the need for a filter in-line with the bilge pump. A fiberglass chard got sucked into the pump during a particularly rousing SF Bay sail. My guess it was rough enough for the bilge water to really slosh around down there. When we docked the pump came on and never shut off. All the chard had to do was hold a little rubber pop-it valve up and the bilge pump runs but moves no water. I installed a raw water filter inline.

Phil Agur, Wing Tip C270 LE #184

Drippless Packing Gland I have never been an advocate of the billows type. Primarily, because if there is a fracture (for whatever the reason) in the billows, you have an immediate emergency. To fix a regular stuffing box leak you can use extra packing, strips of rag, or shoe laces to jam in so you can get back to port. In fact you can completely redo your gland (in the water) with regular flax packing - see C34 Tech. section in the upcoming May 2000 Mainsheet. I've used "Drippless Packing" for the past 10 seasons and think it's great. I've changed it once, but that was my fault because I just had to see how it was doing. It was doing well until I screwed with it.

Ron Hill, APACHE #788