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AdamY · 28-06-2006, 11:03

Okay so my boatyard debacle continues and I need a new shaft. While installing the packing into the nut my mechanic said he wasnt a big fan. I t old him I would like to use it anyway. I know people can be prejudiced about these kinds of things. He told me a boat he recently worked on had something like it and could never get it to stop leaking.

Today he reiterated his concern. And pointed out that the package said the packing is only warrantied for 1 year. He said he has never seen a warranty on packing and has seen flax packing that worked for 15 years on a boat before.

then he pulled some packing he had lying around in the shop and it looked identical to the GFO packing I have. didnt look damaged looked just fine. He said the trawler they were working on across the yard had installed that packing just 4 months prior and could never get it to stop leaking.

I know this guy and ha ve worked with him extensively and believe he is just trying to sell me on what he believes in best. So, I was hoping folks could help me reasses my decision to stick with the GFO packing. If anybody is wondering what it is you can buy it here...

http://www.gore.com/en_xx/products/sealants/packing/gfo_packing_fiber.html

Thanks in advance

Richhh · 28-06-2006, 11:19

Your 'mechanic' probably doesnt know how to stuff a box!!!!
The testimony of almost the entire chemical process industry that has almost entirely changed or is rapidly changing to GFO from flax and other packings ought to be enough.

There are some tricks however that can enhance the sealing of ANY 'problem' stuffing box. When cutting the GFO, etc. into individual rings, instead of cutting 'across' the packing to make a 'butt cut'. cut across the packing with a 45 degree angle. Doling this 'bevel cut' be sure that the finished length of ring is sufficient (or even a teeny bit longer) so that the 'ends' are totally in contact when installed around the shaft. This will cause the 'ends' of the ring to compress together and stop any butt-cut leakage.

Of course if the shaft is rough, galled, etc., nothing will stop the leakage. Its always good practice to pull the shaft, inspect it and 'dress' it back to proper surface smoothness before reinstalling - most 'yard mechanics' wont do this.
;-)

AdamY · 27-07-2006, 11:21

Okay so the boat is (miraculously) back in her slip. After over 4 months in the boatyard.

I ran the new shaft in idle at the dock and got an occasional drip, just a couple drops. It seemed a bit tight but I assumed from all the anecdotal evidence I have heard that a small drip at idle would likely mean a good sized pour at full throttle and didnt loosen the nut.

We got underway and the stuff must have swelled or something because the drip was gone at full throttle. I got worried since I just got a new shaft and didnt want to damage it and so I went into the engine room and put my hand on the stuffing box from teh packing nut all the way aft to the rubber and it was cool to the touch, not even a bit warm.

I checked it after 2 hours of hard running upriver at 6kts (I couldnt believe how fast we were going upriver) 2500 engine RPM and it was still completely cool to the touch and not dripping one bit. I know I am supposed to let water pour out of it for the first while but this thing is cold and not leaking a drop. Should I still back it off and let water pour in or just be happy it seems to be working perfectly right out of the gate?

In any case, I dont think ill of the result so far

CSY Man · 27-07-2006, 11:52

I installed one of those GFO packings some 4 or 5 years ago.

To make it stopp leaking I had to tighten the nut to the point that the whole thing was running warm, almost hot.

I took it apart again and lubed the packing with some kind of expensive teflon grease I had laying around.
(Syntef, page 258 in the West catalog.)

That cured the problem for good, the shaft did not leak again, and stays cool even when powering for 20 hours straight.

I have not payed attention to the packing ever since and feel kind of guilty for not checking or changing it, but as long as it works good, I just may leave it alone.

AnchorageGuy · 27-07-2006, 17:06

been using this stuff for years and it is the next best thing to a dripless system and oh how much less expensive. Have about 5000 miles on the current packing and it needs no attention.

hellosailor · 06-08-2006, 14:39

Adam, I think packing a shaft is akin to filling a tooth. Even uses some of the same tools, the picks and such, and you're working in a place you usually can't see or access very well by yourself. (I say this after my dentist congratulated me on the temporary filling I put in going into a holiday weekend last year.<G>)

I'm sure there are different brands of dripless packing and each is a little different. But you have to consider all the parts:
1-The packing material
2-The condition of the shaft
3-The skill of the mechanic in cleaning the old stuff,
cleaning the shaft (needs polishing?)
cleaning the shaft housing
applying the new packing properly.

Unless the mechanic looks like a Keebler Elf no one is going to be happy, patient, or comfortable working back in there.

If it is all done right--clean and by the book--the bottom line is that the old packing materials don't and can't lubricate like the new ones do. The old packing materials will swell up and wear and abrade and decay more than the new ones will. Yeah, the may be cheaper and maybe they forgive someone's working habits in a way they've gotten used to...but sooner or later, better materials get invented and applied.

These is them!

Warranty? Who knows, if you made the stuff would you really warranty it any longer, not knowing how much it was used, or who installed it? It's like dental floss (Gore makes that too, literally). Either it works or it doesn't, and if you know how to use it and they didn't make it wrong somehow...it's going to work.

ASPSEAL · 20-04-2009, 16:27

As both a boater and someone that has been in the seal and packing business for 20 + years, I feel uniquely qualified to comment on this.

GFO, developed by W.L. Gore is an exceptional product. It is made of a blend of PTFE (Generic for Teflon) and Graphite. Both products are naturally lubricious the frictional characteristics are at a minimum against. The advantage of having graphite added to the PTFE is the heat is conducted away from the shaft instead of insulated to it as pure PTFE packings do. It also reduces "cold flow" so the packing does not move, opening leak paths.

Sometimes it is difficult to convert old dogs and to show them new tricks, but GFO is worth the effort. The industry standard for so many years was flax, but flax is a plant, and as a result it will rot. We have sold this packing to industrial chemical, power, and waste water (read sewage) plants all over the country. Because it is long lasting and abrasive resistant, it will by far outlast any plant fiber packing (inlcuding hemp, and ramie).

Dave

gonesail · 20-04-2009, 18:39

i removed some rotten flax packing from my boat and it was nasty stuff .. the smell was bad and it was falling apart not to mention leaking. i stuffed it with GFO and have been happy for a year.

Hiracer · 22-04-2009, 16:05

Quote:

Originally Posted by CSY Man

To make it stopp leaking I had to tighten the nut to the point that the whole thing was running warm, almost hot.

Mine is not running hot, but it does leak more than I like.

If I keep tightening and it don't get hot, am I OK?

Or is heat not really the test?

Unit was repacked with the GORE stuff about 2.5 years ago by a yard. I've been tightening a little bit here and there on an as-needed basis.

CSY Man · 22-04-2009, 17:26

Quote:

Mine is not running hot, but it does leak more than I like.

If I keep tightening and it don't get hot, am I OK?

Or is heat not really the test?

Heat is the test..

If ya have no leaks and a cool running shaft, ya are golden..
No heat means no friction.

Do tighten with very small increments, better to have a drop of water-leak than to burn yer hand...Ideally, neither, which is what I have on my boat.

Almost sounds too good to be true.

Some old-timers says the GFI is wearing away on the shaft..We shall see when I pull it in 20 years..

Beausoleil · 23-04-2009, 14:18

Quote:

Originally Posted by CSY Man

Do tighten with very small increments, better to have a drop of water-leak than to burn yer hand...

Which is why I got one of those $30 laser temperature guns from Harbor Freight! Now I can just point and shoot!

Now if I can just find a marine use for all those stupid catalogs they now send me...

ASPSEAL · 23-04-2009, 14:44

Once you have your packing down to a slow leak ie: 10 drops per minute... you should slowly tighten more. Preferably one flat of the nut position, so from 12:00 to 2:00 for example. Major adjustments will cause wear in your shaft.

You must remember GFO is 60% PTFE which means it can still cat like PTFE packing. I have seen PTFE packing cut into shafts. The reason why is that although PTFE is a soft material when it heats up due to friction it expands at a greater rate than metal. As a result it will actually cut the metal. The graphite that has been added to GFO greatly reduces this problem but overtightening can still induce the reaction.

I hope this helps.

Dave

Quote:

Originally Posted by Hiracer

Mine is not running hot, but it does leak more than I like.

If I keep tightening and it don't get hot, am I OK?

Or is heat not really the test?

Unit was repacked with the GORE stuff about 2.5 years ago by a yard. I've been tightening a little bit here and there on an as-needed basis.

Hiracer · 23-04-2009, 14:54

Thanks guys. I like the laser gun idea. Will hit Harber Freight on the way home tonight.

CSY Man · 23-04-2009, 15:22

Quote:

Which is why I got one of those $30 laser temperature guns from Harbor Freight! Now I can just point and shoot!

Good idea: That temp gun is also useful for finding leaks around the fridge and freezer boxes as well as other uses on the boat.

Thanks for the reminder, I need to get myself one..Been borrowing the neighbors gun over the years, but he just moved to the UK and kept his gun..Bastard..