Changing stuffing in rudder and shaft boxes - The Hull Truth

Classic Trade · 02-10-2003, 01:16 PM

How often do you change the stuffing around your rudder and staft logs and what brand of stuffing do you use?

Arthur

LI Sound Grunt · 02-10-2003, 01:33 PM

Good question.

My Carver is 13 years old and have never done it - doesn't leak. This will be interesting to see other's experiences.... Also, is this a normal preventive maintenance item or do I wait until it starts leaking more than a few drops?

scratcher · 02-10-2003, 02:09 PM

I'm not sure what the longevity of the stuffing is...it is probably tied into how many hours you use the boat, what rpms you run at etc. My experience is that you should get at least two years and maybe 3 or 4 years out of it. The best stuff seems to be the teflon impregnated used in conjunction with the teflon grease (syntef). There is also, I believe, a material made with gore-tex that I have not used, but have read good things about. A number of shamrock owners who have used the teflon impregnated packing material report no drips at all and only a slight warming of the stuffing box. My own experience is a very slow drip, and a barely warm stuffing box. When you replace yours avoid the common mistake of socking the stuffing box down too hard immediately after repacking it.

sokolj · 02-10-2003, 04:37 PM

I believe that frequency can be a function of shaft alignment, too.

hogfish · 02-10-2003, 05:10 PM

The only time you replace the packing is when you can't take up anymore slack and it continues to drip. Once it gets to that point you pull it down and replace all with new...making sure you stagger the seams.

The correct way to tighten a standard stuffing box is to have a small amount of water weeping while the shaft is turning...one drip at a time is all you need to know it is getting lubed. If you tighten until there is no weep you are likely running the packing dry and increasing the chance of scoring the shaft. Once the shaft is scored you will get very short life of the packing and have a continual pain in the axx.

I've used both natural and synthetic. The natural will swell and stop leaking when the shaft stops. It will also wear faster and score the shaft easier if you overtighten.

The synthetic has always been harder for me to adjust without over tightening but works fine. It will not score the shaft as easy.

No matter what you use this is not a passive part and it needs to be checked on a routine basis to make sure leaks are not happening beyond normal.

modunlavy · 02-10-2003, 05:13 PM

Do you keep the boat in the water?

I didn't have a real problem with keeping mine adjusted until I started keeping my boat on a lift.....The packing is really designed to stay wet.

I just bought the dripless shaft seal system from PSS. Haven't used it yet, but not supposed to have to readjust for taking in and out of the water....

just something to consider since I don't know how you store your boat...

MD

Classic Trade · 02-11-2003, 08:00 AM

My boat is stored in the water. I have always had I/Os and am new to the inboard game. I just stepped up to a Bertram 28 and am a little paranoid about how to maintain stuffing around the rudders and shafts.

Arthur

trouty · 02-11-2003, 08:58 AM

Supposedly once it's over a drip a minute you should tighten or if necessary repack.

The new dripless seals SHOULD remove the need to constantly tighten the stuffing box.

As a "generalisation" - taking inboards in and out the water on lifts etc MAY be expected to speed up the problems with stuffing boxes.

Basically once the shafts are dialled in while the boats in the water - the effect of removing the boat from water CAN mean the water pressure supporting the hull and pressing in equally from all sides, should keep the engine beds in the exact same spot, but once you haul her out - all that weight bears down with gravity, and isn't counteracted by bouyancy pressure on the outside of the hull, prtessing inward, so the engine beds within the hull structure, MAY move ever so slightly - meaning the shafts NOT now truly aligned and hence stuffing box packing takes pressure from one direction more than another.

Put her BACK in the water, and it moves yet again (hopefully back to the origial position the shaft aligner dialled in) but the stuffing remains possibly compacted more one side of the shaft than the other and an increase in drip rate can thus be expected.

Course you have to weigh this minor inconvenience up against the disbenefits of keeping her in a slip.

Hope this helps.

Cheers!