Replacing Stuffing Box Packing In Water

[Charlie]

Originally Posted by Chief Engineer

I have done Tugboat packing in the water.....we are talking 12" shafts.

The amount of water that comes in is minimall as long as you have a decent bilge pump.

You've got me Cheif. How does the type of bilge pump affect how much water comes in?

[Sam Plan B]

I own a Columbia 41 and changed the packing in the water. I was worried about a gush of water but that didn't happen. Like the people say, it's just a steady trickle. I found the hardest part was crawling over the engine and hunkering myself into a space that was way too damn small. And so I worked real fast. It took less than 5 minutes to complete the task and then 20 minutes to get out of there.

[Chief Engineer]

Originally Posted by Charlie

You've got me Cheif. How does the type of bilge pump affect how much water comes in?

It doesn't......the amount of water that comes in will be pumped out as long as you have a decent bilge pump

First you want to take the packing nut off.

Then you cut one ring of packing making sure it is the right size..
i.e. packing should not extend above threads of stuffing box.
Then cut the remainder of rings you will need.

After extracting the old packing...I usually flatten the packing a little bit to make it easier to install in the packing nut.

After each ring, I tighten the packing nut.

If it is GFO I tighten the packing nut BY HAND,,,no wrenches...until leak stops.......Run vessel in gear.......retighten packing nut untill leak stops.
DO NOT OVER TIGHTEN

[Mark Zarley]

Measure ID of packing gland, subtract diameter of shaft, divide by 2. This is the size of packing needed. Like chief says flatten before installing, I put mine on a board and pound it with a hammer till it is thin enough to slip right in.

[psneeld]

repack in the water is no problem...for a tool...sometimes
I have used long drywall screws after breaking 2 or 3 regular packing pullers...drive them in with a screwdriver and work them back out with vice grips,

[sdowney717]

If it is GFO I tighten the packing nut BY HAND

that s great packing, it is soft silky feeling and I tighten by hand also.
It runs cool and is dripless. I still stagger the rings.

The old flax packing was hard, drippy, wore shafts, ran hot unless you let water come through.

People came up with other packing expensive box designs to try to run drip less, but with GFO, all of those are obsoleted.
I recall seeing carbon rings, rubber bellows, having to inject water with tubing, burping the air out of the gland.

GFO® fiber dripless packing is a braided propeller and rudder shaft packing that you can install and forget about. After 15 years of successfully handling demanding industrial pump applications, it's now proving itself in the marine field, too. It's already being used by the US Navy and Coast Guard and many commercial work and fishing fleets. And, it's approved by the American Bureau of Shipping.

[psneeld]

Originally Posted by sdowney717

that s great packing, it is soft silky feeling and I tighten by hand also.
It runs cool and is dripless. I still stagger the rings.

The old flax packing was hard, drippy, wore shafts, ran hot unless you let water come through.

People came up with other packing expensive box designs to try to run drip less, but with GFO, all of those are obsoleted.
I recall seeing carbon rings, rubber bellows, having to inject water with tubing, burping the air out of the gland.

never really had any of those problems...especially on slower turning shafts...takes a couple outings to get it right...but then it would stay that way for years (hundreds of hours).

[fsuhansell]

Thanks so much for all the advice. I did the job last night and was able to repack the glad and stop the leak. I put on a wetsuit and jumped overboard with some butyl tape and sealed up the shaft from the outside before I started. That stuff works amazingly, not one drip with the packing glad fully off. I had bought 1/4 5/16 and 3/8 flax packing because I wasn't sure the size I would need. After removing the old flax (3 rings) with a bend pick I could see it was 5/16 so I cut 3 new rings and began jamming them in the packing nut. The main lesson learned here was make sure you pack each one in as far as possible or they won't all fit. I was only able to get two new rings back in. I went back in the water and took off the butyl tape and tightened up the nut until there was about 1 drip per 10 sec. Tonight ill run the engine and spin the shaft to a bit and see if I can get it tightened down just right.

All in all the entire job was pretty straight forward, the butyl tape was a huge help not having to rush or worry about water coming into the boat. While I was underwater I discovered my shaft zink is loose, so it looks like ill be back down there with some allen wrenches after work today.

[sdowney717]

never really had any of those problems...especially on slower turning shafts...takes a couple outings to get it right...but then it would stay that way for years (hundreds of hours).

mine was always dripping a goodly stream, tighten to slow it down it would not last, go for a run and it was leaking a lot again. I like now that it is drip less.

I have read that flax packing can wear shafts and mine did have wear.

[hellosailor]

I'd expect a self-vulcanizing tape (i.e. silicone tape, rescue tape) could be wrapped around the shaft from the outside to create a waterproof seal that would easily peel off afterwards.

But instead of clay, try a toilet bowl ring. About $4, beeswax, so if there is any that you don't get off it is just a lubricant, rather than an abrasive.

Either way should work.

I'd also suggest a teflon packing material (the GoreTex folks make one) and having a helper around, just in case someone has to make a phone call or fetch a pump. Or reseal the shaft outside while you're inside.