GFO packing problem

[patagonian]

Hi,
I want to replace my flax packing with GFO packing.
I read that it must be used with no grease or lubricants.
The problem is that my stuffing box has a bushing that is lubricated by a grease pump.
From the motor to the propeller, my boat has:

flexible coupler, packing receptacle, bushing (rear part of packing receptacle) with a hole for the grease fitting , hose, stern tube, cutlass bushing.

So, GFO will be contaminated with grease.
I don't know if that forward bushing is needed, I assume that without it the shaft is only supported by the coupling and rear cutlass, maybe not enough.

But doesn't the shaft will rub with that forward bushing (or maybe the stern tube also) when motor vibrates on its soft engine mounts ? ) (It's a Yanmar 2GMF)

I do not know in detail these traditional stuffing box systems, please help me to clarify.

Thanks in advnce

[patagonian]

I found an image that's exactly what I have in my boat (taken from http://alchemy2009.blogspot.ca/2013/...d-guide.html):

[patagonian]

I'm thinking if could be possible to lubricate the front bearing with water instead of grease (via a seacock)
Any thoughs ?

[model 10]

Originally Posted by patagonian

I'm thinking if could be possible to lubricate the front bearing with water instead of grease (via a seacock)
Any thoughs ?

I don't see any "front bearing"? Is it just a slip joint and not a bearing? A Flax packing does not use grease any more than GFO does. What's wrong with the stock set-up anyway?
If there is a regular bearing that needs grease or a slip joint, it is not going to live long with salt water as a replacement for grease I would think twice about plumbing water into the boat .

[patagonian]

I wanted to say bushing instead of bearing...
The part named "body" in the picture is really a bushing.
I've been told that the grease inlet is used for the bushing AND the flax.
I'm concerned too about a water connection via a seacock, but the stern tube is filled with water anyway.
I just discovered that Vetus is using that setup and recommends a seacock or a derivative of the inlet water to the engine connected to the grease inlet.......

[model 10]

A flax packing does not use grease. It has wax in it that is supposed to melt from the friction and seal the shaft. The excess grease from the bushing probably does not go any further than the first ring of packing. It would probably be the same for GFO. If water can't get in, neither can grease.

[transmitterdan]

Originally Posted by patagonian

Hi,
I want to replace my flax packing with GFO packing.
I read that it must be used with no grease or lubricants.
The problem is that my stuffing box has a bushing that is lubricated by a grease pump.

What exactly is the problem with the grease? GFO claims to be inert so it's hard to understand what bad things the grease will do to the GFO.

[CSY Man]

I used GFO for years.
It ran hot. Pulled it off and lubed with Teflon grease.
That solved all my problems. (The Teflon grease was a small grey container from West Marine.)

Yup, the GFO people said not to add any lube or grease, I did anyway.
Would not add any petroleum lubes though.
I lucked out, and the right combo lasted 5 years with hardly a drop of salt water in the bilge.
Big difference from the old flax packing.

[patagonian]

The GFO package says in big letters "DO NOT ADD GREASE OR OTHERS LUBRICANTS - THESE CAN HINDER PERFORMANCE "

As a little drop from the stuffing box is needed I hate greased water in the bilge ...

[CSY Man]

As a little drop from the stuffing box is needed I hate greased water in the bilge ...

The point is to not get drops of salt water in the bilge. It smells and it corrodes stuff in the bilge.
GFO has lubricant built in so you can tighten the stuffing box enough to almost shut off the salt water.
I did, but got heat build up when running.
Kind of defeating the purpose.
Had too much time on my hands so I kept experimenting and found that Teflon lube would eliminate heat and leaks.
It worked for me, it may not work for you...
(Don't try this at home)

[patagonian]

Could work, but I tend to follow manufacturers advices.
Who else knows better their product ?
I wonder if water via grease inlet will act as a cooler...

[phipseml]

With a normal flax packing, you tighten the forward set screw just enough so there is no water coming in while the shaft stands still, but a few drops per minute when the shaft is rotating (i.e. when motoring or sailing with shaft rotating). It's a bit adjustment needed, but quite easy, safe, well proven and cannot go more wrong then getting tiny amounts of water in.

The idea there is that the bit of water flowing through cools and lubricates the packing while when standing still the wax in the packing seals the shaft. If you do not let the drops come, you might get air into the gland and run it hot - so seeing the drops could be considered as a feedback for that the gland is full of water and not air. I have seen the ones with the grease adding hole and guess that's for making it extra water tight by adding a water impermeable barrier and more efficient lubricant to the packing. I read people using it in the way that they get water in while motoring (drops) and add a squirt of grease when done to tighten up completely. Everybody hates water in the bilge, but the few drops per minute prevent you from not running the gland hot and melting the hose.

The GFO packing works differently in that you can keep it just tight enough for water to stay out even when motoring. That seems to be partly due to its different heat conductivity properties, but I don't know too much about it since it's not available here. Follow the instructions and then observe the system for heat as suggested in the post by CSIman.

Cheers,
Phil

[patagonian]

Very clear.
But the question is "to grease or not to grease"
Or more precisely " to grease or to water flow"
The lubrication of that front bushing is my big question thing
I've seen also the same arrangement without that front bushing :
Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine How To at pbase.com (Re-Packing A Traditional Stuffing Box)

[phipseml]

If the instructions say don't use grease, then I wouldn't use grease. In fact, I would even get a new gland without the greasing hole - how is that hole connected to the stuffing material? Will water come out of it when not filled with grease? Another thought could be to use that hole to connect a hose for airing the stuffing.

If it runs hot anyway, you might have tightened it too hard (GFO instructions are clear on this, I think), or something else is different from an ideal case. In that case silicon grease, as suggested above, might be the solution.

[patagonian]

Thank you very much for your opinions and sharing experiences.
I think I'll try with water flow at the inlet grease nipple.
Anyway the original grease system will remain installed so changing will be only a matter of unscrewing one nipple and screwing the other.
At this moment my boat is at the boatyard in the process of getting a new propeller shaft, stern tube, cutlass bering, etc, after 30 years of service.
Thanks again, I'll post the final results.