Packing gland

[higgs]

I put 200 hours on my engine this year and after the cruise, pulled the boat into its slip. After a week the packing gland suddenly started leaking pretty bad. tightening it took care of the problem for now. My plan is to replace the packing for next season, but I am wondering how many of you feel that is not neccessary, now that the new adjustment is holding fine. I guess I am hoping for a bunch of "you are OKs" so I don't have to repack it next spring. It was repacked 2 years ago - probably close to 300 hours of use since then.

 

[Stu Jackson]

Oh, c'mon -- just replace it

sooner the better. It's easy to do, in the water. Do an archiv search on your subject and you'll find all the info you need.

 

[Pete]

winter job

I will suggest that if it has stopped leaking after you tightened it you will most likely be OK. Also since winter in NY is almost here, you will pull the boat ? If so repack it over the winter or better yet replace it with a drip less shaft seal and be done with it for 10 years. If however you decide to winter in water my suggestion would be to repack it now. You should be able to get several "tightenings" from most packing. Most packing (unless overtightened and damaged) will last much longer the 300 hour but better safe then sorry and replace during lay up.

 

[Chris Burti]

Repack...

I'd be concerned a bit that your packing might be sand or heat damaged as in my experience it is not too typical for a stuffing box to suddenly start leaking badly from only normal wear. If is now working properly after running in gear for an hour or so and if you are uncomfortable with the thought of repacking it in the water, it might hold until your winter haul...just keep a close eye on it...remember we don't know why it started leaking suddenly in the first place. I would recommend that you consider using GFO packing material when you re-pack rather than waxed flax or a mechanical seal. GFO is dripless and will last indefinitely due to extremely low friction and heat build up. It doesn't shrink and will not score shafts even when laden with sand. It is used by the US Navy, the Coast Guard and many commercial fleets. It is also approved by the American Bureau of Shipping. I have had GFO for two years and I purchased enough of the stuff for three applications at an industrial supply for for just a few bucks. They use this stuff in high pressure, high speed, industrial pumps...far more demanding applications than a stuffing box on a 3600 RPM diesel sailboat. (no, I do not have any economic interest in the product or company)I am in the camp of those that do not see any need for the expense, complexity and additional maintenence rquirements of a mechanical seal. Yes, yes, I know that the manufacturer of the leading dripless seal says they have never had a catastrophic failure...but Murphy was not a pessimist...he was an engineer and Murphy's Law should be considered an engineering principle not an aphorism.You will also want to check your cutless bearing wear and engine/shaft alignment or bent shaft, as packing leaks can be a symptom of shaft problems.Good luck and fair winds,

 

[RichH]

What kind of nuts are on the adjusting studs.....

If the nuts are "Nyloks" (a nut with a nylon 'plug' to retard slippage): they can only be used/tightened "ONCE" and then should be replaced each time you tighten or remove them. If you have nyloks ... change them to 2 solid nuts per stud.

 

[captain dave]

either or

A properly packed box will allow at least one if not two tightenings; I agree with running it for an hour to see if it's Ok or just blown out.

 

[Rick I]

You probably have another 200 hours or so left

higgs,When it starts leaking badly you can turn it down a bit once or twice or maybe three times. I don't normally replace mine until I can't turn it down anymore and it still leaks badly. I always have the flax aboard and usually replace mine while the boat's in the water. It takes about 40 minutes. If you have replacement flax aboard you shouldn't have to worry. RichH, Yours must be a full keeled boat. Most stuffing boxes just have a large locking nut. No studs.

 

[Bill Roosa]

The cruise did it

I suspect the "more than normal" number of hours per trip you put on the gland during the cruise just caused it to wear normally but you noticed it more.Telling if a gland packing is finished is an art. You have to know what it felt like when you put it in and how "hand tight" it was when the leaking stopped. Then you just re-tighten to that level of "hand tight" as the packing wears. Not that easy as it is usually a season or more between adjustments. A packing is worn out when the amount of "hand tightening" shows an increase in effort. Another way of saying this is the gland nut took x amount of torque to get it to stop leaking when it was new. After break in it took x amount of torque to again get it to stop leaking. After a period of time the gland wears and you re-torque to x again to get it to stop leaking. When you see the amount of torque the gland takes to get it to stop leaking increase much beyond x the gland packing need to get replaced.

 

[Stu Jackson]

Guys, all we can do is offer some

advice, but nobody still knows what he has in there to begin with. He never mentioned what it was or is. Gore, regular flax, or the green goop. So, I think we've said about everything he can figure out, unless there's still another opinion...? I just figure you're right, tighten up a bit and wait til haul-out, but why not just fix it now? OK, rhetorical question, no answer required. All the best, Stu