2, 3, 4 layers of packing in stuffing box?

[FishFinder]

Recently discovered my rudder stuffing box had 4 layers (or rings) of packing, while my propeller shaft box had only 2. Both were leaking more than they should have been, I'm replacing the packing now. Wondering if I should stick with the # of layers that were in there (4 & 2) or try to get them both to work with what seems to be the standard 3 layers?

[scottyt]

for the shaft its simple as many will fit and allow a few turns of the nut. then adjust to the desired drip rate.

for the rudder i dont know

[sailingdog]

Basically, put what will fit in them.

[DrB]

I don't 3 is the norm either. My SB holds 4, I maybe able to get 5 in of the newer GTU Packing as it doesn't swell as much as the older flax packing, but when I removed the old flax, I pulled out four so I replaced with 4. SD is right, put as many "rings" as will fit. Try this technique:

Remove all the old stuff first, and then pack the first two rings of the new stuff in and snug firmly down, Loosen packing nut and put a third ring in and tighten again pretty snug. Continue adding rings and tightening until you can't get the packing nut to get a full turn on the SB threads before tightening. Once you get the max material in, tighten until the drip rate is at the level that you want while the shaft is stationary and spinning.

The general rule of thumb for the SB is while the shaft is not spinning, you should not see any drips for at least a few minutes, preferably none at all, and while the shaft is spinning a 2 to 5 drips/minute. The main thing to remember is that the drip rate is not the sole measurement, adjust the packing nut so that while the shaft is spinning, the drip rate is results in no heat build-up in the shaft.

For the Rudder post, you should adjust just snug enough so that there is no evidence of drips even even when turn the shaft. Do not over tighten or you can bind the shaft.

DrB

[mrforest]

Like the previous person wrote...put whatever fits in and good luck

[FishFinder]

Originally Posted by DrB

I maybe able to get 5 in of the newer GTU Packing as it doesn't swell as much as the older flax packing
DrB

So the packing swells eh ... I'm asking because I got the new fancy GTU packing here in 2 sizes, 1/4" and 5/16". The old packing appears to be in-between these sizes. So I should go for the smaller-appearing 1/4" I suppose and it will swell to fit?

[floatsome]

First time repacking new-to-use boat. The boat is out of the water and the shaft is disconnected from the transmission, so I can experiment on the workbench.

My problem is that I don't know what size packing to use. The old packing consisted of 4 rings (hard and densely packed, thicker vertically perpendicular to the shaft axis than along the shaft axis). Measurements tell me that 1/4" should fit, but 1/4" teflon impregnated packing is a bit hard to fit in. I can get it in, but can only fit 3 rings, and then have about 3-4 threads on the packing box when I screw it down not too firmly. Shaft is 7/8".

1. Will that packing swell, or compress more over time?
2. Should I drop down to 3/16" packing, if I can get it?

[tommays]

While you can deform any packing to fit if you squish it enough it does not really swell

I have seen plenty of people bang it flat with a hammer to get a "GOOD" fit when they had to small of a size

So it should be pretty snug fitting it but not require a BFH

[sailingdog]

Why would they have to bang it with a hammer if it was too small a size???

Originally Posted by tommays

While you can deform any packing to fit if you squish it enough it does not really swell

I have seen plenty of people bang it flat with a hammer to get a "GOOD" fit when they had to small of a size

So it should be pretty snug fitting it but not require a BFH

[Gary M]

3 rings of 1/4" should be fine. Believe it or not my packing gland only has room for 1 ring of 1/4". I did cut one ring lenghtwise and so I have 1 and 1/2 rings in there but it works fine so 3 rings should be plenty.

Gary