how tight is your stern gland?

[GreyLady]

 

The older I get the looser it seems to be. I never remember involuntary farting when I was younger...

 

I think thats true y'know my dad trumps all the time now he is 65, every 5 minutes he trumps or has to leave the room quickly due to the unexpected aftermath.

[swift1894]

 

Just out of interest can anyone confirm or deny that black packing ( graphite ) is for steam joints and white packing is for water joints and are they interchangeable. Thanks

Darren

I've never understood why graphite ( which is the highest noble metal on the galvanic scale) is used in stern gland packing.

Technically it means all other metals in contact with it will become anodes and corrode.

Maybe the fact that it's mixed with grease means there's no reaction????

 

https://en.m.wikipedia.org/wiki/Galvanic_series

[MtB]

 

I think thats true y'know my dad trumps all the time now he is 65, every 5 minutes he trumps or has to leave the room quickly due to the unexpected aftermath.

 

 

|I think the term for that is 'following through' lol!

[GreyLady]

 

 

|I think the term for that is 'following through' lol!

 

Thanks for clarifying whot i meant lol MtB

[MtB]

 

Thanks for clarifying whot i meant lol MtB

 

 

Lol you have much to learn, Grasshopper.

 

 

(No-one here seems to 'get' that reference!)

[Barry]

 

 

Lol you have much to learn, Grasshopper.

 

 

(No-one here seems to 'get' that reference!)

 

It was on my mind but I chose not to speak it

[MtB]

You must be older than you look...

 

(Not sure if that was a kompliment!)

[dogless]

"When you can take these stones from my hand it will be time for you to leave"

 

Rog

PS I'm not referring to Saturday afternoon wrestling !

[DHutch]

Just out of interest can anyone confirm or deny that black packing ( graphite ) is for steam joints and white packing is for water joints and are they interchangeable. Thanks

 

Darren

Personally I would use graphite impregnated for everything over and above the ptfe impregnated.

 

- Certainly everything on the steam engine is graphite, and as far as I know the stern tube is as well.

- Our shaft speed is so low that in 24 year we have never repacked it, although I one turn four years ago.

 

As for tightness, I don't subscribe to the 'it should leak' camp, the steam glands on our valves/rods dont leak with 200psi behind them after all. I just hold the spanner near the nut end and maybe add twice the force that the spanners own weight supplies, 2-3 flats each side, maybe once a year? Turn on greaser every other day, again due to the slow shaft speed.

 

 

 

Daniel

[ditchcrawler]

Personally I would use graphite impregnated for everything over and above the ptfe impregnated.

 

- Certainly everything on the steam engine is graphite, and as far as I know the stern tube is as well.

- Our shaft speed is so low that in 24 year we have never repacked it, although I one turn four years ago.

 

As for tightness, I don't subscribe to the 'it should leak' camp, the steam glands on our valves/rods dont leak with 200psi behind them after all. I just hold the spanner near the nut end and maybe add twice the force that the spanners own weight supplies, 2-3 flats each side, maybe once a year? Turn on greaser every other day, again due to the slow shaft speed.

 

 

 

Daniel

I think it has al lot to do with alignment, vibration and side forces. My shaft is connected to a hydraulic motor via a doughnut flexible drive, the shaft is supported by a fixed thrust bearing, The packing has been tightened once in 13 years and doesn't drip, for most of that time the nuts were finger tight at the most, the only time it drips is if the prop is fouled so out of balance badly

[Cavalier Jon]

It took me a while to work out why my boat come equipped with a massive spanner and a rubber mallet, until I worked out that my stern tube opening is not like that of other boats. I don't get the two-bolt luxury that makes for straightforward stern tube adjustment.

 

So it's taken me about nine months aboard but i think I've finally got the hang of not sinking - rubber mallet, huge spanner, righty-tighty!

[Barry]

"When you can take these stones from my hand it will be time for you to leave"

 

Rog

PS I'm not referring to Saturday afternoon wrestling !

 

The walk along the rice paper

[Emerald Fox]

 

I think thats true y'know my dad trumps all the time now he is 65, every 5 minutes he trumps or has to leave the room quickly due to the unexpected aftermath.

 

 

Thank you for that information, I'm sure your Dad is proud of you...

I've never understood why graphite ( which is the highest noble metal on the galvanic scale) is used in stern gland packing.

 

 

 

I thought graphite was a non-metal? A polymorph of the element carbon.

Graphite is a polymorph of the element carbon. diamond is another polymorph. The two share the same chemistry, carbon, but have very different structures and very different properties.

 

Diamond is the hardest mineral known to man, Graphite is one of the softest.

Diamond is an excellent electrical insulator, Graphite is a good conductor of electricity.

Diamond is the ultimate abrasive, Graphite is a very good lubricant.

Diamond is usually transparent, Graphite is opaque.

Diamond crystallizes in the Isometric system and graphite crystallizes in the hexagonal system.

Somewhat of a surprise is that at surface temperatures and pressures, Graphite is the stable form of carbon. In fact, all diamonds at or near the surface of the Earth are currently undergoing a transformation into Graphite. This reaction, fortunately, is extremely slow.

All of the differences between graphite and diamond are the result of the difference in their respective structures. Graphite has a sheet like structure where the atoms all lie in a plane and are only weakly bonded to the graphite sheets above and below. Diamond has a framework structure where the carbon atoms are bonded to other carbon atoms in three dimensions as opposed to two in graphite. The carbon-carbon bonds in both minerals are actually quite strong, but it is the application of those bonds that make the difference.

 

It may seem strange that one of the softest minerals (and a very slippery lubricant) is the high-strength component in composites used to build automobiles, aircraft, and of course golf club shafts. It is the weakly bonded sheets that slide by each other to yield the slipperiness or softness. Yet when those sheets are rolled up into fibers, and those fibers twisted into threads, the true strength of the bonds becomes apparent. The threads are molded into shape, and held in place by a binder (such as an epoxy resin). The resulting composites have some of the highest strength-to-weight ratios of any materials (excluding, of course, diamond crystals and carbon nanotubes).

 

Graphite can only be confused with the mineral molybdenite which is metallic bluish silver in color. However, molybdenite is much denser and has a silver blue streak.

 

Most graphite is produced through the metamorphism of organic material in rocks. Even coal is occasionally metamorphosed into graphite. Some graphite is found in igneous rocks and also as nodules inside of iron meteorites.

 

 

PHYSICAL CHARACTERISTICS:

Color is black silver.

Luster is metallic to dull.

Transparency crystals are opaque

Crystal System is hexagonal; 6/m 2/m 2/m

Crystal Habits include massive lamellar veins and earthy masses. also as scaly granules in metamorphic rocks.

Hardness is 1 - 2

Specific Gravity is 2.2 (well below average)

Cleavage is perfect in one direction.

Fracture is flaky.

Streak is black gray to brownish gray.

Associated Minerals include quartz, calcite, micas, iron meteorites and tourmalines.

Other Characteristics: thin flakes are flexible but inelastic, mineral can leave black marks on hands and paper, weakly conducts electricity.

Notable Occurrences include New York and Texas, USA; Russia; Mexico; Greenland and India.

Best Field Indicator is softness, luster, density and streak.

Edited September 10, 2015 by Emerald Fox

[swift1894]

 

I thought graphite was a non-metal? A polymorph of the element carbon.

.

Yes you're right.

It's just that it's at the top of the galvanic scale so any metal that comes into contact with it will act as an anode, but looks like the grease in the stern gland prevents this.

[Emerald Fox]

Quickie before I have to return to work - anodes. Ours are from 2006 I think. Any ideas how we can check do they need to be replaced when we do the blacking next Summer? The water tank is empty at the moment so the nose of the boat has risen from the depths, but the anodes are still below the surface.

I mean, it would be wise to have new anodes waiting to be welded on, wouldn't it?

Is there a simple way to lift the nose out of the water a bit to see what they look like?

How does one know which type and size to get?

 

Also - has anyone here used Rylard's Water Tank Paint - a bitumen I'm guessing. It's black, anyway! We painted out tank recently and it's drying over 11 weeks - when we fill up with water for the first time should we leave it to stand for a few hours and drain away before filling up with fresh water again? Will residues seep out of the paint the first time it's in contact with water? Only for shower - we don't drink from the water tank (yes, yes, I know everyone else does).

[nicknorman]

Quickie before I have to return to work - anodes. Ours are from 2006 I think. Any ideas how we can check do they need to be replaced when we do the blacking next Summer? The water tank is empty at the moment so the nose of the boat has risen from the depths, but the anodes are still below the surface.

I mean, it would be wise to have new anodes waiting to be welded on, wouldn't it?

Is there a simple way to lift the nose out of the water a bit to see what they look like?

How does one know which type and size to get?

 

Also - has anyone here used Rylard's Water Tank Paint - a bitumen I'm guessing. It's black, anyway! We painted out tank recently and it's drying over 11 weeks - when we fill up with water for the first time should we leave it to stand for a few hours and drain away before filling up with fresh water again? Will residues seep out of the paint the first time it's in contact with water? Only for shower - we don't drink from the water tank (yes, yes, I know everyone else does).

Just get the boat in some reasonably clean water (eg rivers, bits of BCN) and you will be able to see them, especially if you look though a glass dish etc on the water to eliminate the surface reflections (think glass bottomed boats). A waterproof torch helps too.

[Plonk]

 

The walk along the rice paper

So.. after the rice paper was it the branding with the red hot Squirrel ?

[Barry]

Ah yes the red hot pot.

 

But was it a squirrel, a dancing tiger, or a dragon?

[tree monkey]

Ah yes the red hot pot.

 

But was it a squirrel, a dancing tiger, or a dragon?

A dragon, I loved that program as a kid

[Capt Ahab]

You shouldn't need that much. If you do (to stop drips) you are going to end up with a hell of a lot of grease coming out of the prop shaft into the boat. Messy! If it does need that much, the gland needs adjusting.

It did make a mess - thicker packing cord did the trick. Half a turn it is now.

[ditchcrawler]

 

 

Thank you for that information, I'm sure your Dad is proud of you...

 

I thought graphite was a non-metal? A polymorph of the element carbon.

Graphite is a polymorph of the element carbon. diamond is another polymorph. The two share the same chemistry, carbon, but have very different structures and very different properties.

 

 

We were told never to mark a gas turbine engine with a pencil because of the graphite and aluminium. I wonder what Nicks view is.

[Bob the welder]

Lol you have much to learn, Grasshopper.

 

 

(No-one here seems to 'get' that reference!)

how old are you.?

[Phil Ambrose]

We were told never to mark a gas turbine engine with a pencil because of the graphite and aluminium. I wonder what Nicks view is.

Aha yes, back in the late 60s early 70s there was a fire at RR Derby, when the fire was extinguished they set about squaring the place up. They thought all the engine components etc would be OK because they were made of nimonic stainless steel, good for white hot temperatures. But no, upon inspection many small fractures were discovered, these it transpired were caused by us engineers writing in the components, calculations etc, that sort of thing.

Immediately RR sent out a directive along with explanation to all engine part suppliers. The carbon of the pencil was absorbed by the metal and heat then effectively altered it.

Phil

[Jess--]

Aha yes, back in the late 60s early 70s there was a fire at RR Derby, when the fire was extinguished they set about squaring the place up. They thought all the engine components etc would be OK because they were made of nimonic stainless steel, good for white hot temperatures. But no, upon inspection many small fractures were discovered, these it transpired were caused by us engineers writing in the components, calculations etc, that sort of thing.

Immediately RR sent out a directive along with explanation to all engine part suppliers. The carbon of the pencil was absorbed by the metal and heat then effectively altered it.

Phil

similar experience when working with titanium, pencils were banned from being anywhere near it.

[Laurie Booth]

 

The walk along the rice paper

And lemember Glasshopper always expect the unexpected