off hand no, but it might be on the paperwork which is back in Cyprus. I won't be back there till the end of September. At least 316 I would suspect.
Regards
Ian
On 28/07/2010 11:09, Richard03801 wrote:
Ian thanks for the reply. Do you know what grade of stainless you used?
Regards Richard Piller
On Jul 27, 2010, at 11:39, Ian Shepherd <sv_freespirit@... <mailto:sv_freespirit%40yahoo.co.uk>> wrote:
Hi Richard,
I am not sure if I mentioned that the stainless prop shaft bush has
been
in use for over three years with no signs of any adverse effect.
Regards
Ian SM 414 Crusader
On 02/07/2010 14:13, Richard03801 wrote:
Thanks for the info. One question how much clearance did you plan between the shaft and bushings? Metal to metal ss to ss normally does not work well. If they touch they will Gaul as the bronze is used
as a
bearing surface. It may be that the bearing pack is stiff enough to hold the shaft from moving/touching. I guess time will tell. Regards Sent by Richard Piller
I read recently that owners modifications can be detrimental to the original concept. Maybe so, but here are three modifications
that have
definitely improved my boat.
Three and a half years ago I replaced the bronze main engine
prop shaft
bush with one made of high grade stainless steel. I recently
hauled for
the first time since fitting it and there was absolutely no wear whatsoever on the bush. Just a very slight polishing of the surface where the lip seals mate to the bush. There was no noticeable
wear to
the seals either after 600 hours of motoring, but I changed them
anyway.
This contrasts markedly to the normal wear experienced on the
standard
bush. I believe that the maintenance interval is now much longer
with
the stainless bush, and there is a worthwhile long term cost
saving too.
I replaced the 70M of chain supplied by Amel with 90M. There was a noticeable improvement in the boats motion particularly in short
seas.
The boat pitches less, hardly ever slams any more and because of
this
maintains a higher average speed. I also have 10M of chain and
100M of
rope for my second anchor stored in the forward locker together
with my
two Fortress anchors, so in reality, I have the equivalent of
100M of
10mm chain in bow. The extra weight forward certainly seems to
be for
the better.
I decided to try and improve the lubrication of the bow
thruster, which
seems to have more sea water inside it than oil most of the
time. The
arrangement of a single lip seal over a rough fibre shaft is hardly conducive to keeping the sea water out. I removed the shaft and
had it
machined down to accept a thin stainless sleeve for the lip seal
to run
on. I then replaced the three open ball race bearings, which
were all
rusty, with sealed bearings running in their own grease. Of
course this
prevents you pouring the oil in via the top of the tube, so I
decided to
not use oil to lubricate the bevel gears, but instead use water repellent grease.
This was packed into the gearbox housing before the back plate was refitted, leaving a small gap to allow for expansion, and grease was also placed between the outside of the outer bearing and the lip
seal.
This was done about four months ago, and the bow thruster has never sounded sweeter. Gone is the awful sound of bearings running is
a sea
water emulsion, and there does not seem to be any loss in power
either.
Time will tell, and I shall remove the bow thruster this winter
to see
if the modifications have had any adverse effects on the gears,
but it
is my guess that the life of the seal, bearings and bevel gears
will be
considerably increased.
As they say, cruising is fixing things on water. Anything that
reduces
wear and subsequent failure must be for the better.
Ian Shepherd SM 414 Crusader
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]
