Marek:
Thank you for the reassurance.... I changed the packing myself (and with
mentor ship from a knowledgeable club member in the cockpit)....the
packing is not compressed very much...in fact , when wraping the
packing, when I first put on 3 wraps I couldn't get the compression nut
on, too tight......so I took one off, compressed the 2 on the shaft and
then backed everything off and then put on the third wrap and barely
compressed all 3.....and two things.....it is a rare occasion for me to
motor more than 2 hours at a time and when I have, and two, checked the
shaft and box with my hand for heat, there was none, not a hint of heat
immediately after motoring for several hours. So I am not really
worried about a scored prop shaft and my stuffing box does not leak.
Why would I want to change this?
Rob Abbott
AZURA
C&C 32 - 84
Halifax, N.S.
On 2018-02-18 3:17 PM, Marek Dziedzic via CnC-List wrote:
The only reason for water dripping is to lubricate (and cool) the
seal/shaft interface. However, the PTFE packing has low enough
friction that you don’t need to lubricate. Hence, no need for
dripping water.
Btw. the main difference between the normal shaft seal (regardless of
packing) and the dripless (e.g. PIY) is that in the former the seal is
beaten the shaft and the packing box and in the latter it is between
two faces of the seal (the shaft does not participate in this seal).
Having said this, I don’t think your PTFE packing would score the
shaft in any reasonable time. When it does you may have other reasons
to replace the shaft, anyway.
Marek
*From:*CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of
*robert via CnC-List
*Sent:* Saturday, February 17, 2018 10:04
*To:* Neil Andersen <neil.eric.ander...@gmail.com>; cnc-list@cnc-list.com
*Cc:* robert <robertabb...@eastlink.ca>
*Subject:* Stus-List PSS Shaft Seal
I used PTFE Tefelon Braided Ramie Packing .....I repacked my stuffing
box 6 years ago with it....after Spring launch I adjusted for approx.
2 drops/drips per minute....then after running the engine the drips
would stop....I loosen and got the 2 drops per minute again...after
the next use of the engine, the drips would stop....loosen one more
time, ran the engine and the drips would stop.
So I stopped loosening....ran the engine for 2 hours .....got into the
lazarette and put my hand on the stuffing box and the prop shaft
looking for heat....both were cold so I left things the way they
were. The stuffing box does not leak/ drip water although I
understand it should. I may be in for a big expense some day for a
new prop shaft but in the meantime, my bilge is dry except for what
comes down inside the mast when it rains. I can live with that, we
all do.
Rob Abbott
AZURA
C&C 32 - 84
Halifax, N.S.
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