"Valeria Dal Monte" wrote in message
...
I have this old hydraulic backstay tensioner (approx. 1980) but I have no
idea of what it is. Apparently it is not one of the more common brands.
Do you have any suggestion?

What is your question?

Are you trying to figure out how to put it back together?
How much it's worth?
Where to get parts?
How to use it?


If you are trying to get it repaired, my suggestion would be to look in the
phone book under "Hydraulic Equipment, Repairing". Find a shop, take all
the pieces down to them and see what they say.

Rod

Valeria Dal Monte wrote:

I have this old hydraulic backstay tensioner (approx. 1980) but I have no
idea of what it is. Apparently it is not one of the more common brands.
Do you have any suggestion?

It is a fairly simple machine with few moving parts, the job should be easy
to get your backstay tensioner working again. Finding the correct parts might
not be so simple.

The most common problem is leaking hydraulic fluid. It may need a shaft or
sleeve seal, which most likely is a rubber or soft plastic O-ring. The
control valve may be leaking, which would allow the tensioner to slowly (or
not so slowly) lose it's tension without any apparent leaks on the outside of
the cylinder.

If you get a big pan, you can take the tensioner apart without getting
hydraulic fluid all over everything. Then you can get a good idea what parts
are needed. Often, hydraulic fluid gets a little water in it which corrodes
interior parts. The valves & inside wall of the cylinder can be lapped &
polished; although it may be easier to replace the valves.

Your picture did not come through. Would you consider posting it at
www.webshots.com and posting a link to the picture here? We could give better
advice after seeing it.

Fresh Breezes- Doug King

"Valeria Dal Monte" wrote in message
...
I have this old hydraulic backstay tensioner (approx. 1980) but I have no
idea of what it is. Apparently it is not one of the more common brands.
Do you have any suggestion?

Navtec is fairly common.

http://www.navtec.net


/Marcus

--
Marcus AAkesson
Gothenburg Callsigns: SM6XFN & SB4779
Sweden
Keep the world clean - no HTML in news or mail !

On Wed, 12 Nov 2003 10:48:26 -0800, "Rod McInnis"
wrote:
If you are trying to get it repaired, my suggestion would be to look in the
phone book under "Hydraulic Equipment, Repairing". Find a shop, take all
the pieces down to them and see what they say.

================

Probably the wrong answer. Take it too a sailboat rigging specialist
and they'll probably know what it is. Any large marina that handles
sailboats will have a rigger on staff or contract with one.

Doug,
thankyou for your long reply. Following your advive I posted the picture in
the following link:
http://community.webshots.com/photo/...99953239ZGLvQd

The backstay adjusters does not maintain the tension and leaks slightly
around the rod and around the small pump cylinder. What I need is a
complete set of new seals and, probably, new stainless steel balls that act
as valves. My problem is: I don't know the exact size and kind (compound,
shape, etc.) of the seals and the size of the balls and such information
could be obtained from the original manufacturer.
Just to anticipate a possible question: finding the size of the seals is
actually possible by just measuring the pistons and the bores; what is more
complicate is a guess on the kind of seals and the size of the ball-valves.
Unfortunately the device appears to have been already "overhauled" by
personnel who substituted parts that clearly do not fit.

Regards
Daniel
SPAM

"DSK" ha scritto nel messaggio
...
Valeria Dal Monte wrote:

I have this old hydraulic backstay tensioner (approx. 1980) but I have
no
idea of what it is. Apparently it is not one of the more common brands.
Do you have any suggestion?

It is a fairly simple machine with few moving parts, the job should be
easy
to get your backstay tensioner working again. Finding the correct parts
might
not be so simple.

The most common problem is leaking hydraulic fluid. It may need a shaft or
sleeve seal, which most likely is a rubber or soft plastic O-ring. The
control valve may be leaking, which would allow the tensioner to slowly
(or
not so slowly) lose it's tension without any apparent leaks on the outside
of
the cylinder.

If you get a big pan, you can take the tensioner apart without getting
hydraulic fluid all over everything. Then you can get a good idea what
parts
are needed. Often, hydraulic fluid gets a little water in it which
corrodes
interior parts. The valves & inside wall of the cylinder can be lapped &
polished; although it may be easier to replace the valves.

Your picture did not come through. Would you consider posting it at
www.webshots.com and posting a link to the picture here? We could give
better
advice after seeing it.

Fresh Breezes- Doug King

Daniel wrote:

Doug,
thankyou for your long reply. Following your advive I posted the picture in
the following link:
http://community.webshots.com/photo/...99953239ZGLvQd

Thanks for the picture, I downloaded it so I could study it in detail.
Unfortunately I can't really give much further helpful advice.



The backstay adjusters does not maintain the tension and leaks slightly
around the rod and around the small pump cylinder. What I need is a
complete set of new seals and, probably, new stainless steel balls that act
as valves. My problem is: I don't know the exact size and kind (compound,
shape, etc.) of the seals and the size of the balls and such information
could be obtained from the original manufacturer.

But a local hydraulics shop should be able to give you a lot more detailed help.
From the picture, I couldn't tell if the problem was corrosion or mis-sized
seals.


Just to anticipate a possible question: finding the size of the seals is
actually possible by just measuring the pistons and the bores; what is more
complicate is a guess on the kind of seals and the size of the ball-valves.

If the surfaces have not been damaged, then it should be possible to get the
thing working again. The ball valves and springs are very important (you already
knew that) and a hydraulics shop should be the best bet. In fact they may be
able to grind out the valve seats to fit new ball valves.... buy a spare set
from them, if water gets into the hydraulic fluid (fairly common with these
things) then the springs go bad quickly.




Unfortunately the device appears to have been already "overhauled" by
personnel who substituted parts that clearly do not fit.

If you're lucky, the same person did not get a chance to work on your boats
electrical wiring!

Fresh Breezes- Doug King

Doug,
thank you again for your interest.
I have finally found the origin of the device through the net: the name is
Trident 300 and made by Spencer Carter, Cornwall UK. Useless to say that
the manufacturer does not make them anymore but passed the task of customer
support to a nearby company (www.staytensioner.com) where Les, a nice guy,
helped me. Now that I have new seals and a drawing and will soon fix the
thing.
How did I finally find all this? Through another very nice guy at
Nautors-Swan who knows the wherabouts of (almost) all the swans in the
world!

Well, thank you again and keep in touch
Daniel