Stuffing box service - how to

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stevd

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Has anyone come across a good stuffing box service guide on the web or anywhere for that matter. I need to do mine, but I have never done one before, and I am the sort of person that likes to get as much info on a subject before starting it. :-) or if anyone in Holyhead is willing to show hows its done, there is a beer in it for you :-D

Many thanks
 
Perfect thanks for that Greggron! Just what I was hoping for!

Im still open willing to accept offers of help in Holyhead though :-D
 
I've just done mine on a small installation. My packing was slightly oversize so I had to flatten it a bit and push it down into the gland nut with a blunt screwdriver. I won't know if it seals until i launch. One thing to be sure of is that you must clean out the old packing completely.
 
Some recent experience of mine. I repacked the stern gland on Cecilia using PTFE packing. It ran hot from the first time we started up, even with the nuts backed off so much that the yoke plate was rattling. We poured seawater over it in the hope it would settle down but it didn't happen. I then repacked using ASAP's graphited cotton, then motored well over 100 miles with no overheating whatsoever.

I suspect that PTFE is fine if everything is perfect but its poor thermal conductivity and relatively high coefficient of expansion work against it if there is some vibration and misalignment.
 
vyv_cox said:
Some recent experience of mine. I repacked the stern gland on Cecilia using PTFE packing. It ran hot from the first time we started up, even with the nuts backed off so much that the yoke plate was rattling. We poured seawater over it in the hope it would settle down but it didn't happen. I then repacked using ASAP's graphited cotton, then motored well over 100 miles with no overheating whatsoever.

I suspect that PTFE is fine if everything is perfect but its poor thermal conductivity and relatively high coefficient of expansion work against it if there is some vibration and misalignment.
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I used graphited cotton too, absolutely no problem over the last 18 months
 
Question: how often should the stuffing be replaced and if the gland is dripping at rest can it just be tightened to rectify or is that the cue for replacement?
 
greggron said:
Question: how often should the stuffing be replaced and if the gland is dripping at rest can it just be tightened to rectify or is that the cue for replacement?
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Ideally, the gland doesn't drip at all when the shaft is at rest. When rotating, it's best if there is a drip or two per minute. That proves that it's not too tight, and gives some lubrication. As for replacing, if it's dripping, and cant be stopped by tightening a little, it may be time to re-pack. This could be many years. Theoretically, the usual graphite packing doesn't need any grease, but I pump in a little when leaving the boat for a period.
 
vyv_cox said:
Some recent experience of mine. I repacked the stern gland on Cecilia using PTFE packing. It ran hot from the first time we started up, even with the nuts backed off so much that the yoke plate was rattling. We poured seawater over it in the hope it would settle down but it didn't happen. I then repacked using ASAP's graphited cotton, then motored well over 100 miles with no overheating whatsoever.
Click to expand...

Some recent experience of mine....... EXACTLY the same as Vyv!!! Even to the detail of replacing with ASAP's finest!!!
 
I took Vyvs advise and used graphite impregnated. I'll tell you how well it works when I'm back in the water. I've got a greaser too which I've refilled but not sure if I'll use it. Graphite is a dry lubricant ain't it?
 
captainboo said:
Exactly the same here and also replaced with ASAP'S graphite version a month ago! Couldn't get the ptfe version to run cool at all.
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I used the ptfe stuff it did take a bit of adjusting at first, to hot or too many drips but after 3 seasons I hardly touch it now. After the advise I think I'll try the graphite stuff next time.
 
Thanks for all the replies. My stuffing box has a grease feed going to it. If I use this graphite packing material, I dont need to worry about the greaser?
 
stevd said:
Thanks for all the replies. My stuffing box has a grease feed going to it. If I use this graphite packing material, I dont need to worry about the greaser?
Click to expand...

As I said earlier, grease is not essential, in fact you can push too much grease into it, but I generally give the greaser half a turn or so when leaving the boat. That way, even if it was inclined to drip occasionally, then it won't.
 
quick tip from a marine engineer friend about stuffing box and what is hot and what is not.......if you can keep your hand on it, it's not hot. unless some of the experts know better...........but I've repacked stuffing boxes a couple of times and never had a problem
 
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