Stuffing box question

[zeehag]

how many of us have bronze shafts these days? none of my boats has ever had one--how about you guys---

 

[Anonymous 121765]

A73,

I did not see this mentioned before but, there are cases where the shaft tube may have an airlock. This could happen when splashing the boat after yard work and/or launching trailerable boats.

I have the PSS shaft seal, and when splasing the boat need to "burp" the air out.
This is just a suggestion as an airlock can cause a heat buildup.

CR

 

[Ralph Johnstone]

The shaft can get 'necked'ie where the packing is agroove will form.adjustment causes the packing to compres in the groove, when in gear the prop thrust moves the shaft forward and friction=heat occurs, this will also harden the packing. if the shaft has awear groove then the gland will never work.Unsrew the nut and pull it fwd to expose the shaft where the packing runs. You got a groove right? A pro(cest moi) can fix it by minimally installing a one piece rubber seal- swedish starts with v- the seal part will be on unworn part of shaft.the pro may need to go as far as replacing shaft, ,coupling skeg bearing flex coupling bolts re allighnment etc.its a boat job right? Some early catalinas were fitted with bronze shafts-softer than stainless.If there is an experienced marine mech who has done lots of shaftline work in your area why not consult him for an appraisal? the whole system needs to be assessed as to easiest best result.Cheers

harden the packing

I think Sonofason may have come the closest to putting his finger on the problem when he identified the possibility of shaft damage. If that's the case, the best material and installation practice won't count one whit. New undersized packing, new oversized packing, new oversized packing which has been hammered back to the correct size, shouldn't cause this many problems.

Again, as I mentioned in post #36, removing the nut is quite simple and temporarily sealing it (using string) is just as easy. Then you can assess the condition of the shaft, packing, etc. And, more importantly, you can report back to us just what is going on in there. I don't know about the rest of you, but this one is giving me sleepless nights wondering WHY.

 

[SEMIJim]

how many of us have bronze shafts these days? none of my boats has ever had one--how about you guys---

Abracadabra had one until this spring.

Had either GTU or GFO packing in the packing gland, too. Didn't seem to cause a problem. Freshwater boat.

Jim

 

[Ajay73]

I put the boat in the travel lift and changed to the 3/16" packing. Tried to get the 1/4" packing out with various picks and I think because it was oversized it just wouldn't come out. Was just packed in too tight. I also have very little room between the threaded end of the bronze tube and the nut with it backed up against the coupling so it very difficult to get good leverage on a pick. So pulled the shaft out of its coupler and pulled the packing nut off. I used the GTU packing. Put in 3 rings, staggard joints. Put it all back together(was really pretty quick overall)and went for a 45 minute run out our channel and back. The infrared thermometer read 98 F, basically luke warm, on the packing nut. And I could tell when turning the shaft with the coupler that it turned easier than it did with the 1/4" packing. So, problem solved and I'm a happy camper.

 

[SEMIJim]

Good to hear, Ajay!

Jim

 

[Anonymous 121765]

Ajay,

Way to nail it pal.

If I remember it, I thought you mentioned you were not getting a drip. That's why I mentioned a possible airlock.

However, the gremlins that were causing this, I think you killed them all..

CR

 

[Stu Jackson]

Good news. Funny how sometimes we can actually help.