Cape Dorys Stuffing Box Material

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

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jbsails
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Location: Cape Dory 25D
"Sumiko" Edgewater, Fl.

Cape Dorys Stuffing Box Material

Post by jbsails »

Ahoy All,

I have a question about my Cape Dory 25D Stuffing Box packing material. In my CD owners manual it says: “All CDY stuffing boxes use ¼â€
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Ray Garcia
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Post by Ray Garcia »

I have been using Graphtex Ultra (GTU) Flax Shaft Packing with W.L. Gore fibers and graphite fibers that are impregnated with Teflon PTFE. The packing is made to be thermally conductive and in my usage I have found it pretty durable.

I replace the packing every other season. Yes, some people get more usage but I am not taking any chances in that department. I see it as the only thru-hull that does not have a valve on it. Only thing that comes between the boat and disaster is $10 worth of packing and a little discomfort for an hour or two replacing it. I haul every season so I replace it just before launch.

The biggest problem with any material is friction/heat rendering the material stiff to the point where leakage develops. The instinct is for the owner to tighten down the packing nut which drives the material into the shaft. Eventually scoring develops on the shaft which could lead to an early replacement.

The other choice is a PSS (packless sealing system) which uses no packing material in the stuffing box. The unit is installed and is maintenance free. I know quite a few people out there have them installed on their CD's and swear by them. There is also a huge discussion on pro's and con's. Do a search and you should find a few nights worth of reading.

Be the way, welcome; it's a great place here isn't it?

Rg
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Carter Brey
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Re: Cape Dorys Stuffing Box Material

Post by Carter Brey »

[quote="jbsails"]Ahoy All,

I have a question about my Cape Dory 25D Stuffing Box packing material. In my CD owners manual it says: “All CDY stuffing boxes use ¼â€
jbsails
Posts: 18
Joined: Mar 22nd, '10, 09:43
Location: Cape Dory 25D
"Sumiko" Edgewater, Fl.

Stuffing box material

Post by jbsails »

Thank you Ray and Carter for the great advise. I knew I would get an answer from the Board! It is truly a great group of sailors with a lot of knowledge.
Fair Winds,
John
Paul D.
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Post by Paul D. »

I have the bronze packing gland use 1/4" PTFE flax with teflon goop. I have used the regular waxed packing but the goopy stuff feels more slippery when I change it two years later. I use three rings of the packing material. Has worked well but I do get water in the sump when motoring, perhaps I don't tighten it enough. It is hard to see the drip rate while adjusting and I would rather have it looser than too tight. I reckon it is dripping a bit more than every ten seconds. You can drive yourself nuts adjusting it perfectly.

The shaft was very slightly scored when I bought the boat nine years ago. I repacked the first time I launched and have again every two years with fine results. I may try the GFO and try tightening her up a bit more though.

Hardest part is getting the old packing out. I found a drywall screw works well to draw the packing out but will try a dental pick next spring. A big flathead screwdriver and hammer make an easy job of working the stuffing box.

Don't eat a big meal before heading down there! And it is nice to have a helper hand you down the stuff you forgot to place where you could reach it. Also, if alone it is important to make sure you prop open the locker lid.

The one I have is B165 in the Spartan catalog

http://spartanmarine.com/catalog.html
Paul
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Oswego John
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Post by Oswego John »

.....contribute to this thread. But alas, search as I might, I can't find the shaft packing gland on my Typhoon.

Years back, in my salad days, I used to rely on flax packing that was coated in graphite. It was pretty slippery stuff. Dirty, too. I haven't seen or heard of it in a long time. What with all the modern advances made in the industry, maybe they don't make it any more?

Anyone remember iflax with graphite?

And that's my 2¢
O J
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Post by Maine Sail »

Guys,

GFO, GTU and Johnson-Duramax Ultra-X are not meant to be 100% drip free. They are drips less not dripless. You should have some leakage even with the new stuff if for no other reason than to prevent crevice corrosion of the shaft due to stagnated water.

I would surmise CD's message on Teflon was specific to Teflon impregnated into natural flax. It can harden with heat and score a shaft worse than traditional flax without Teflon. Standard Teflon can become quite abrasive when subjected to heat. The Gore based products are MUCH more thermally conductive and offer about 300+/- % less friction than does traditional flax packing..

Traditional flax is even more thermally conductive than traditional flax w/Teflon and is at a minimum about 5X less thermally conductive than the Gore based packings.
-Maine Sail
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Cathy Monaghan
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Main Sail is right...

Post by Cathy Monaghan »

Guys,

Main Sail is correct. If you have the standard bronze stuffing box found on most of our Cape Dorys, they use flax packing. And no matter what it's coated with, the packing nut should not be so tight as to prevent a slight drip while the shaft is turning. It shouldn't drip while the shaft is idle, but it must drip while the shaft is turning. The water inside the stuffing box, as well as that drip, provide the cooling for the shaft as well as the box itself. While the shaft is turning, it should drip 2 to 3 drops per minute.

Here are some online resources regarding stuffing boxes.
If you want a dry bilge, replace your old stuffing box with a dripless shaft seal.

By the way, I did that on our CD32. I installed a PSS Shaft Seal. And while I was at it, I installed a DriveSaver (this required that the shaft be shortened by 1 inch). You certainly don't have to do that, but I decided to go with the PSS Shaft Seal and the DriveSaver since I had to remove the shaft to install a new cutless bearing. While I was at it I had the prop reconditioned as well. I figured that if I was going to go through the trouble of removing the shaft, I might as well do all that stuff while I had the chance.

Cathy
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Re: Main Sail is right...

Post by Maine Sail »

Cathy Monaghan wrote:
Here are some online resources regarding stuffing boxes.

Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay
All those links and you forgot the best one... :D

http://www.pbase.com/mainecruising/stuffing_box
-Maine Sail
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Russell
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Post by Russell »

I used the synthetics for years without issue. I always figured, as already mentioned, my CD manual was written well before the newer packing material came out.

When I repowered I did switch to a PSS shaft seal which I am extraeamly pleased with. Just remember, dripless systems are not maintence free and failure to do the very simple maintence can be catastrophic. Stuffing boxes on the other hand require a bit more work to maintain, but any failure is managable.

Anyway, dont hesitate to use the newer high tech packing material available, reguardless of what your 20+ year old manual tells you. You will get great results, longer lasting, less drips and likely even less shaft scoring then the traditional packing recommended.
Russell
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s/v Lady Pauline Cape Dory 36 #117 (for sale)
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Cathy Monaghan
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bronze or stainless....

Post by Cathy Monaghan »

I believe that the instructions in the Cape Dory manual are referring to the use of packing material on bronze shafts. Our boats had bronze shafts originally. Probably most of them have been replaced with stainless steel shafts.

You can use the teflon or PTFE impregnated flax packing, or even the green goo, with a stainless steel shaft. Bronze is a much softer metal, and the high heat that can be generated by packing material with PTFE and other synthetics can score or deform the shaft causing permanent damage. That said, regular flax packing that's not changed often enough, dries out, gets hard, and at that point will damage the shaft. It should be changed every year whereas the packing material with PTFE can go around 5 years before it needs repacking. I think that with proper maintenance, not over-tightening the nut, and physically checking the stuffing box every now and then while motoring to see if it's too hot (you should be able to touch it), you should be able to use the packing material impregnated with PTFE with a bronze shaft too. That's my 2 cents anyway -- could be wrong though.

Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay
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