Dripless vs Stuffingbox

Don S/V ILLusion · Jan 23, 2016

It appears from your picture there is plenty of room to adjust a traditional stuffing box.

Stu Jackson · Jan 23, 2016

druid said:
and it seems the hardest part is getting the old stuffing out

Nope, not, nada...

I hear this all the time. People simply use the wrong tool. I did lots of research on this before I tackled it the first time, back maybe in 1999 or 2000 after we bought our boat in 1998. I then wrote it all up (http://www.c34.org/wiki/index.php?title=Stuffing_box_packing) and have been updating it with links to Maine Sail and the newer stuffing material like Ultra X. You might have seen that in your travels.

A drywall screw is all you need. Those pigtail corkscrew things simply are too big to use on 1" shafts with boxes. There is NOT enough clearance.

That article discusses the pros & cons of the PSS, too.

Your boat, your choice.

Deleted member 117556 · Jan 23, 2016

I went with the new packing material from west marine and it works great and is dripless.
bob

JamesG161 · Jan 23, 2016

druid said:
I need to replace the stuffingbox on my Ontario 32 (long story!). Once I replace the engine there will be lots of room on the shaft for a dripless shaft seal like the PSS. But two problems:
1. I'm not sure the larger diameter of the shaft seal will fit (see pic). There is a beam under the stuffingbox that I think USED to actually hold it (hence the need for the flex coupling!). It's now floating, but there is maybe 1/4" clearance under the existing stuffingbox.
2. The stuffingbox is cheaper, and with the new teflon "stuffing" they're pretty much dripless as well.

The PSS is not a flexible shaft coupling.
It is just a spring compression type rotary seal. The Bellows are the "compression spring".

The thing that wears is a replaceable Carbon composite versus your shaft with a packing friction.

PSS is "Dripless" as long as the Bellows and its clamps are in good condition.

Since my PSS carbon has less than 200 hours, I am not sure of the life of the carbon.

Shaft/Engine alignment should be done by new Cutlass bearing and engine mount shims normally, I may be wrong when you are putting in a new engine.
Jim...

Stu Jackson · Jan 23, 2016

druid said:
AND I can do it out of the boat

I understand. But wouldn't you eventually end up doing it in the boat? Same answer.

Siamese · Jan 23, 2016

I've had both. My Catalina 309 had the dripless, and my current Catalina 28 has a stuffing box. When I got the 28 a couple years ago, it seemed like everything on the boat leaked, including the stuffing box. I cleared up the various window leaks and so on, and then turned to the stuffing box.

I was a little apprehensive about it because I'd never repacked one before. I read all of MainSail's advice (which has always served me well), and got started. I'll admit that even after reading all MS's advice I was still unsure which stuffing material to buy. It seems there is some real garbage available (that makes claims to be the greatest ever dripless, etc.), and some other modern stuff that may or may not be compatible with the material of your prop shaft.

I finally decided to just get regular old waxed flax packing material made by Buck Algonquin. Yeah, it'll drip a little but I don't care. I keep a clean bilge, but not a dusty dry bilge.

If I'd decided to go dripless, I'd be into disconnecting the coupling at the engine to do the installation. I read MS's info on that and decided I didn't want to deal with it.

A stuffing box with traditional flax is bound to work, and be easy to maintain with no hidden pitfalls. KISS. I always have the option of changing to dripless, but that would be a very low priority on my to-do list. Dealing with a stuffing box isn't hard, and it's a nice thing to have in your skillset. Degree of difficulty is somewhere around a 3 on a scale of 10.

I will say that it was interesting when I had my boat launched the first time after re-stuffing the box. On the cradle, I had no idea of how much to tighten it, and definitely didn't want to over tighten it. I made sure to have my stuffing box adjusting wrenches right next to the box when the boat went in. The yard put the boat in the water, I hopped on and when below, and water was flowing in a a fairly good rate. HOLY SHxx! I calmly told the yard guys that my new stuffing needed a little adjusting before the removing the slings (note to self...don't panic!). I went below and started tightening it down...more....more....more....good! I fine tuned it a little when I got to my slip and on my first couple excursions with the boat. No sweat.

P.S.
In the process, I learned (from MS) how a stuffing box allows water to lubricate and cool. Think of that little bit of dripping as your cooling system. While under power, I'll occasionally go below and lay my hand on the stuffing box to check it's temperature. So far, it has always been cool or tepid to the touch. All is well.

Roland5048 · Jan 23, 2016

I've had both. The PSS is virtually maintenance free for seven to ten years. The Teflon flax is easy to install if you have good access. Use three rings of flax, off-setting where the rings meet. Also, cut the rings on an angle. Crank it down until you have about a drip every twenty seconds while the shaft is rotating. There should be no drip while in idle. I got my dentist to give me some of his used picks to get the old flax out. If everything is OK, the stuffing box should not be hot while running. If hot, loosen the nut a bit. Hope this helps.

Terry Cox · Jan 23, 2016

Agree with Druid. When we took possession of our current boat in 2002, I repacked the stuffing box with the teflon impregnated stuff. Then decided to repack again in 2010 with the newer stuff. Runs cool, virtually dry most of time, with an occasional drip. Hard to remove the old stuff and get the new in due to the location. Love most of things about the P42, but the stuffing box access is not one of them.

zeehag · Jan 24, 2016

i have had and used the dripless stuffing--- gore tex. good stuff.
friend had pss. ther ewas a rumpor a boat lik emine sank mid pacific. oops th e sinking was allegedly due to pss fail. ol here is what really happened-- the hose clamps rusted apart and oop shappened. he was able to save boat, but onl;y due to the fact these are built so that all is readuily accessible.
how easily accessible is your stuffing box while under way?? if not easily accessible, go old fashioned box with new fashioned gore tex stuffing. that was best option in my ericson and i never had any problems with it--always a dry bilge.
this boat uses a flanged unit with wtf i can find to stuff into it. i use teflon packing in it, and i need to replace that stuffing every time i sail. different kinda boat--different stuff. each is different.

Ralph Johnstone · Jan 24, 2016

druid said:
Yeah, it's really looking like the stuffing box is the way to go. Notwithstanding that it's cheaper, it IS simpler and a more proven system. I do have to research the miriad of packings available...

I would never try to bias you one way or the other re stuffing gland vs. mechanical seal

but I'm coming up on my fifth year of using the same packing and I run it BONE DRY. No leaks allowed.

http://forums.sailboatowners.com/in...to-leak.136282/&highlight=really need to leak

I have only tightened the packing a few times since last installed and it seems that checking the shaft alignment is the only thing that causes any leakage. I could probably get away with six years but I'm easily bored and will probably replace it this year for something to do. I believe that at six years you would start to consider replacing the rubber boot on a mechanical seal. This is somewhat more difficult than a repacking a stuffing box

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As far as packing goes, I'm presently using teflon impregnated flax. I'm sure I could get even better performance if I used goretex or one of the newer, more exotic material but many seem to contain graphite (jet black appearance) which worries me as I don't know what my shaft is made of. Shaft still has a mirror polish under the packing so at least it's not susceptible to crevice corrosion over the unused winters. I don't want to push my luck with graphite packing.

If for some reason you do decide to go with a packing gland, I would be interested to see how a REAL gland performs for you as compared to the spud type most of us are stuck with. This real gland is from Buck Algonquin:

The only problem here is that I haven't been able to find one less than 1-1/4" in shaft size. This is a proper, industrial type of gland as you don't have the inside of the threaded nut (of a spud type gland) tearing at the packing when tightened, and the gland follower of a real gland is tapered to force the packing against the shaft. More expensive I'm sure, but so much better than the spud type which is nothing more than cheap junk. I don't know how mine holds as well as it does.

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Please keep us updated as to how the engine installation goes.

zeehag · Jan 24, 2016

buck algonquin to me, when i sent pix and requested assist with finding a new unit for my boat:
i have never seen anything like that before. we have nothing that will replace that."
as i was looking , in their catalogue, at the item i needed. thankyou, i will buy mexican, at this point, anyone except buck algonquin. yes there are other companies making these items.
btw the flanged unit i needed was 71 usdollars in 2011. from the catalogue. buck algonquin's.

Stu Jackson · Jan 24, 2016

druid said:
I do have to research the miriad of packings available...

Why?

It's all in the link I provided earlier, see reply #4. I've kept it updated and there is nothing new. If do find something not included, please let me know, but I sincerely doubt it.

Maine Sail · Jan 24, 2016

druid said:
Good thoughts and writeup, Ralph. Interesting point about the "real" gland being tapered.

This is the first I have heard of the "real" (gland style) vs. apparently unreal (nut-style) packing glands. There are cheap packing glands, and quality packing glands, but both types can work perfectly well. I see two-bolt glands on sailboats with larger shafts, just as I see the apparently non-real nut-style on commercial boats with large shafts. A lot of what gets installed is based on access..

This is an apparent unreal Buck Algonquin nut-style box and it's tapered....

Ralph Johnstone · Jan 24, 2016

Please pardon my English (or lack thereof) as I was none too clear first time around. I referred to the "gland follower" as being tapered when the correct word was "bevelled" referring to the bottom edge of the gland follower. This is found on the inside edge of industrial pumps with stuffing boxes. It puts more axial force on the outer circumference of the packing ring which in turn acts to push the packing towards the surface of the rotating shaft and seals it. At least that's the theory and it seems to work for large pumps. I have sketched over a drawing of a gland to show in detail the beveled follower.

It still remains that the spud type of packing gland (Buck Algonquin's term) should only be used as last resort where a follower type packing gland won't fit. Cheap design. Unfortunately, the real heartbreaker here is that no one seems to supply a gland follower type of stuffing box with less than 1-1/4"dia. Pity

. You can see that the packing material slides smoothly into the interior of the gland body as it has no rough edges. One of the important factors in running a dry gland is that the packing material must be a tight fit right from the installation and no excessive tightening.

Looking at the spud type gland, I fight to use 1/4" packing in my gland where 3/16" packing would be an easier fit but would take a lot of tightening to stop the initial leakage. Once the packing is that tight, the gland is going to run hot.

The spud type gland tend to chews up the outer face of the packing material as it's being installed. This may result in poor seating of the material. If everything is really greased up, I've had some luck in screwing the packing into the gland nut (using two dental picks) because the 1/4" material is so tight.

Dripless vs Stuffingbox

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Deleted member 117556

SBO Weather and Forecasting Forum Jim & John

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