stuffing box packing

[Kathy L]

Past posts mentioned "GFO" packing. It's time to do my rudders and shafts, where can I find GFO. Thanks,John.

 

[Nonchalant1]

John,

I got mine here.

http://www.e-marine-inc.com/products/gfopacking/packing.html

Doug Shuman

 

[Kathy L]

Thanks Doug.

 

[67hat34c]

what kind of results have others had with this product, I am interested

 

[Genesis]

I love the stuff... have it in all my boxes. Haven't had to change it yet - including in my mains shafts, going on 4 years now.

 

[Nonchalant1]

I think it's excellent. However, you have to be very careful not to overtighten it the first time you put it in. It has to be dripping at the dock before you "run it in" and then tignten it up in small increments after running it a second time and even a thrid time if necessary. If you overtighten it once and overheat it, there's no "undo" button to click.

Doug Shuman

 

[MikeP]

Be VERY CAREFUL to follow Doug's advice, above. I failed to follow the instructions and tightened it too much on initial installation. I therefore got the opportunity to buy the product again and do it over!

 

[Kathy L]

Ordered the packing today, also looked at the instructions on e-marine site, thanks Doug. There wasn't any mention of how many "rings" to use. The old packing had five, that only left 3-4 threads engaged on the nut. I'm not sure how much I would have gained if I had tried to tighten the nut. Any suggestions. Thanks, John

 

[Genesis]

4 is standard if you can get 'em in there. Stagger the cut point 90 degrees (120 if you use 3 rings)

 

[Kathy L]

Thanks, 4 rings makes me feel better with the thread engagement.

 

[Nonchalant1]

I also use 4 rings even though 5 will fit. Here are some additional tips:

Cut it in advance so it'll fit. Use an open area of the shaft or something else that's exactly the shaft diameter. Stretch the GFO length out some before cutting it so it won't be too big due to handling. If a ring seems to fit too short, take it out and stretch it.

Cut it at a 45 degree angle so the cuts overlap each other. I put them in so that if you could look along the shaft you'd see the 45 degree angle as you looked into the packing gland nut.

Buy the flex packing removal tool (like a flexible corkscrew) It'll save you lots of hassle.

Make sure you get all the old layers out. You should be able to scrape the tool on metal-to-metal at the deep end of the gland if it's empty.

 

[Full Moon]

Is GFO the same as teflon stuffing (the white stuff)?

 

[Genesis]

No. GFO is a black packing that looks pretty conventional, other than being completely smooth and tightly-woven.

 

[Maynard Rupp]

Our '86 36C Hatteras has different kind of stuffing boxes. These have a flange with two studs, one on each side. There is a flanged brass cup shaped thing that is inserted in the center and around the shaft. Adjustment is done by tighting or loosening the nylock nuts on the studs on each side. I have the same system on my racing 35' Oyster sailboat, but have never seen this anywhere else. The Hat manual shows the thing clearly and tells you to re-pack with 3 concentric rings with the gaps 120 degrees apart. I have never needed to re-pack any of these things. They look goofy but seem to work well. Our Hat also has a small, soft plastic tube from the sea water pump to a fitting behind the packing area on the housings. This is needed because the props are in a tunnel which creates a low preassure area behind the stuffing boxes. Water won't come in and lube and cool the packing. The little tube supplies sea water right at the packing. Kinda neat eh?

 

[Nonchalant1]

Maynard,

That's the one all of our Hatts have that stuffing box, except without the little tube. The rudder shafts have the more standard threaded gland nut type.

Doug

 

[Genesis]

I have the studded ones on ALL my penetrations - rudders and shafts.

I love 'em. If you put jacknuts on the studs before you install the collar you can jack off the collar for changing the packing! That makes the removal job trivial - and is a 50 cent (literally) change.

This was my first experience with this kind of stuffing box and I love 'em. God, why doesn't EVERYONE use those?!

 

[dwaynec]

I think it was Doug (Nonchalant1) who first mentioned the collar dragging on the shaft. I had the same problem on our boat this year, and was also able to correct it by rotating the hose 180 degrees. That is the only downside I have seen to this type of packing gland arrangement. However, it is pretty easy, at least on our boat, to see the collar and it is pretty evident when it is no longer centered around the shaft.