I am unfamiliar with Gortex packing...
The Goretex packing we were discussing earlier this year is sold by W. L.
Gore and is called "GFO". It is a graphite impregnated woven teflon
material. It looks and handles like black flax packing. It is self
lubricating and 'virtually' drip free. I have been using it for 2.5 years
with great results. It is Mil-spec approved per "Mil-P-24790".
There was concern from several folks about galvanic corrosion between the
graphite in the GFO and the surounding metals (CRES shafts and bronze
packing nuts). To date I have not had any problems, nor has anyone sent me
any first hand observations of problems. I put the word out thru some
surveyor friends, and their SAMS Email net also didn't yield any first hand
galvanic corrosion observations.
I also exchanged Email with Nigel Calder w.r.t. the concerns attributed to
him from his book. He said:
I used graphite packing tape for years with no problems. However, it is
not recommended for marine use because of the possibility of a galvanic
couple. This does not occur with the PSS shaft seal because the graphite
component is physically isolated from the shaft and has no direct
electrical connection (you would need a wire, or something similar, from
the graphite to the shaft to complete the circuit). In the case of the
packing, in theory the direct physical contact provides the circuit,
although as I said in my experieince (including salt water pumps on oil
production platforms) I have not seen problems.
> I am unfamiliar with Gortex packing...
The Goretex packing we were discussing earlier this year is sold by W. L.
Gore and is called "GFO". It is a graphite impregnated woven teflon
material. It looks and handles like black flax packing. It is self
lubricating and 'virtually' drip free. I have been using it for 2.5 years
with great results. It is Mil-spec approved per "Mil-P-24790".
There was concern from several folks about galvanic corrosion between the
graphite in the GFO and the surounding metals (CRES shafts and bronze
packing nuts). To date I have not had any problems, nor has anyone sent me
any first hand observations of problems. I put the word out thru some
surveyor friends, and their SAMS Email net also didn't yield any first hand
galvanic corrosion observations.
I also exchanged Email with Nigel Calder w.r.t. the concerns attributed to
him from his book. He said:
>I used graphite packing tape for years with no problems. However, it is
>not recommended for marine use because of the possibility of a galvanic
>couple. This does not occur with the PSS shaft seal because the graphite
>component is physically isolated from the shaft and has no direct
>electrical connection (you would need a wire, or something similar, from
>the graphite to the shaft to complete the circuit). In the case of the
>packing, in theory the direct physical contact provides the circuit,
>although as I said in my experieince (including salt water pumps on oil
>production platforms) I have not seen problems.
I think this is great stuff (and I don't sell it...)! You can find out
more about it at: http://www.wlgore.com/corp/sealants/packings.html#marine
or
http://www.thomasregister.com/olc/goretetraetch/compress.htm
The Gore Marine folks are:
John Bilas: jbilas@wlgore.com
George Cantler: gcantler@wlgore.com
Order number: 800/455-2854
Good luck,
Louis B. Brydon (WA6OCZ) O-
brydon@ssd.loral.com
SEASTAR - Redwood City, California, USA
