RePack or Dripless Shaft Seals?

GFO and Teflon are not the same. GFO is ePTFE, Teflon is PTFE.

The e (expansion) makes a big difference in the yarn.

Greetings,
Mr. ASD. I too have heard not so nice reports about the "teflon stuff" but I don't think that's what GFO is. In any case, leave in what you have done and get out on the water.
Ah, Mr. NS beat me by 12 minutes...

Alaskan Sea-Duction said:

Well I'm not finished yet. Tomorrow when I get back in the water, I will tie up to the dock, run the engines at idle in gear for about 20 minutes to make adjustments.


The reason I went with regular flax. I got into a in depth conversation with a guy at Englund Marine here in Astoria. They had both the Teflon flax and the regular. He is 74 and he told me that for many many years he has used the regular flax. He has used the Teflon stuff and he had issues with it. He has always had good performance with regular flax and uses it exclusively in his fishing boats. These boats are ran farther and harder than my trawler will ever see. He convinced me.


I went back in to Englund this morning as I was set the take every thing out and use the GTU (GTC?) stuff. He told me I would be fine and was willing to come down to the yard and look at my installation. I showed him my pictures and told me I did a good job. He also told me that after our conversation two boat owners came in and wanted the regular flax and was cussing the Teflon stuff, why I am not sure.


I want to thank all of you as I do fill more comfortable with it now and really do appreciate all TF advice that was given. Thank you.......

Click to expand...

Let me try this again.

Gore GFO is what you want to use. Not G-- anything else.

And GFO is not the same as the old white Teflon crap packing.

https://www.emarineinc.com/categories/GFO-Marine-Shaft-Packing

I put Duramax in my sporty. 2 1/2 inch shafts. No leaks after getting them adjusted right. Ever. Not while running or sitting. Temps are whatever the water temp is. YMMV

"I put Duramax in my sporty. 2 1/2 inch shafts. No leaks after getting them adjusted right. Ever. Not while running or sitting. Temps are whatever the water temp is. YMMV"

This is the reality that makes everything else a poor choice.

When buying GFO , remember to do the rudder stocks .

kulas44 said:

I put Duramax in my sporty. 2 1/2 inch shafts. No leaks after getting them adjusted right. Ever. Not while running or sitting. Temps are whatever the water temp is. YMMV

Click to expand...

Duramax

Well to close this out. We were put in the water yesterday. Ran the boat at idle for 30 minutes. Made a few adjustments. Ran home which was 4 1/2 hr run. Would check out the seals periodically. Made a few adjustments to where it would drip a little. Flange was cool to the touch. Done with this project.....


Thank you for everyone's help and advice.

GFO contains graphite, which can cause problems, but much more likely on a bronze or low grade SS shaft.
Another good case for fresh water flushing here, any type of packing or dripless system holds saltwater captive against dissimilar metals, possibly for extended periods.
So exercise regularly, and flush after every use!

kapnd said:

GFO contains graphite, which can cause problems, but much more likely on a bronze or low grade SS shaft.

Click to expand...

Cite please.

I'm no scientist, but I see the problem with graphite is that it is very high on the scale of noble metals, so the less noble metal interacting with it will become the anode.

kapnd said:

I'm no scientist, but I see the problem with graphite is that it is very high on the scale of noble metals, so the less noble metal interacting with it will become the anode.

Click to expand...

OK so you can cite no actual factual evidence of this ever being an issue with GFO packing then I take it?

Zackly.

Geez, Bill, did you buy stock in GFO?

Capt.Bill11 said:

Cite please.

Click to expand...

Look at the Safety Data Sheet.

http://www.gore.com/MungoBlobs/573/340/safety-information-gore-gfo-fiber,0.pdf


GORE® GFO® packing is comprised of polytetrafluoroethylene (PTFE), silicone oil, and graphite.

Or read what Rod at Compass Marine has to say about graphite-impregnated packing on certain shaft metals: Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine How To at pbase.com

- - -

GFO, GTU & Ultra-X Warning

*WARNING: While I do like the graphite impregnated packings such as Duramax Ultra-X, Gore GFO or Western Pacific Tradings GTU they can be dangerous to underwater metals. I have used it on my own boat but inspected the Aqualoy 22 prop shaft yearly.

Graphite is one of the most noble metals on the galvanic scale and is basically at the top. As such anything in the drive train becomes anodic to the packing. Older "bronze" shafts, really more like a brass because they had high zinc content, can be damaged by these new high tech packings.

The damage shown in this photo happened in one season with intact prop shaft zincs. The shaft was in fine condition when packed and a year later this is what it looked like.

The packing used was Gore GFO a graphite impregnated packing. If you have a bronze shaft use extreme caution with graphite impregnated packing materials.

I don't tend to see these issues with Aqualoy 22 shafting but I have seen it with bronze and lower grades of stainless. Please use these packings CAREFULLY. If you choose them please do check on the shaft periodically.

It should be noted that ABYC P-6 specifically says this:

ABYC Standards:
"6.7.4 Graphite impregnated packing material shall not be used because of the possibility of galvanic incompatibility with the shaft material."

That being said there are thousands of happy boaters who have had decent results with these packings. However, they should not be treated as a "set it and forget it" packing. If using these graphite impregnated products I would suggest checking the shaft at least yearly.

I knew I had read it somewhere....actually several times.


Then again I didn't read it a 100 times so like many things in boating...WTF?


Trying to nail it down and all the required info like what are my boat's components made of so picking new stuff is always a challenge.

kapnd said:

Geez, Bill, did you buy stock in GFO?

Click to expand...

No. But I know it works and have never seen it damage a shaft. So just because someone says it can cause damage doesn't mean I'm just going to take there word for. Unless they've seen it themselves or can point to factual evidence that it does.

And now someone has cited some evidence.

I'm more than happy to learn something new. I'm just not inclined to give much weight to hear say on its own.

Nothing new about the wrong graphite in some industrial pump packing applications causing issues. These issues tend to arise when inadequate flushing occurs. Just the conditions so many on TF seem to praise. That said, my comparing a low use boat shaft to a 24/7 industrial pump is silly. ASD did the right thing. He talked to a pro and ignored us.

A year ago I willingly replaced my flawless decade old PSS units with new, ignoring advice from many on TF. I know, I know just as ASD I

And to be clear, just because I posted that, doesn't mean I'm anti-GFO. In fact, I just installed it on my main shafts and will have it put on my rudder shafts once the snow melts. To me, it's worth any minor risk that the shafts might be inferior stainless and I just intend to monitor them.

After reading Steve D'Antonio's excellent description of how ABYC standards are promulgated (post 61 here: http://www.trawlerforum.com/forums/s4/6vdc-golf-cart-battery-question-17616-4.html#post407596) it's easier to put them in their proper perspective.

sunchaser said:

ASD did the right thing. He talked to a pro and ignored us.

Click to expand...

LOL! Thanks but I did not ignore TF. I used the information you all gave me so I could properly repack the shafts. I did choose regular flax, but I did need you advice....

Granddad (very wise man) used to tell me accept all the advice you can get from those with knowledge and experience. Use what you can, trash the rest........

As a quick follow-up on this subject. After running 3300 miles up and down the Inside passage this past summer, the old style packing performed very well. Only had to adjust once. The port side is starting to leak and it has the G-packing in it too I would suspect. I'll be pulling the boat in March and will re-pack it with the old style packing.

Alaskan Sea-Duction said:

As a quick follow-up on this subject. After running 3300 miles up and down the Inside passage this past summer, the old style packing performed very well. Only had to adjust once. The port side is starting to leak and it has the G-packing in it too I would suspect. I'll be pulling the boat in March and will re-pack it with the old style packing.

Click to expand...

Why?

Just repack it with GFO and forget it for a few years or more.

Capt.Bill11 said:

Why?

Just repack it with GFO and forget it for a few years or more.

Click to expand...

Well I should have done both sides last year and didn't. Goes on the to-do list

repack

I have terrible access to my rudder posts and after fighting them for years installed PSS dripless seals. I'm completely happy with them, and with the same seals on my drive shafts. The failure mode on dripless seals is usually heat which isn't an issue for rudders.

Dripless is great. But install them when you are already going to pull and check your shaft(s) anyway. Makes you feel better about the cost. Make sure you install engine water feed to cool/lube them. Make sure proper fittings are used. Understand how they work and in the case of PSS, the correct way to clean the surface annually to keep the drips at bay.

"The failure mode on dripless seals is usually heat which isn't an issue for rudders."


- or fatigue
- or contamination
- or a strike on the propeller or rudder

There is a lot of good advice on how to repack the packing gland. The only additional suggestion I have is that I take the plastic bag that cleaners use to return your shirts in, and as I draw back the packing nut I immediately wrap the shaft log with the plastic bag and then take some light twine to tie it up and the water inflow generally stops or goes to a mere trickle. Then you can take out the old flax or just add new or whatever you have decided to do for your "repack" without getting anxious about the inflow of water. You will have a lot less stress, particularly if its your first time changing the packing while in the water. Beside the cleaner's plastic bag that I use, probably kitchen plastic wrap would work as well. After the packing nut is ready just take off the plastic and re-thread your nut back on the shaft and you are finished.

Paul

Repack. Modern synthetic materials last indefinitely.

Alaskan Sea-Duction said:

OK I am now convinced to repack. Should I seek out a yard to pull me out and repack it or have someone come to the boat and repack while in the water?

Click to expand...

It depends on the cost. I suspect it would be less expensive to have a pro do it in the water than to have the boat hauled, but you should get prices for each and then decide.