Conference unifix::sailing

    
    We installed a Lasdrop this spring. I believe they've stopped using
    Delrin in favor of a different plastic. We had absolutely no leaks
    even when first installed...
    
    I second Alan's recommendation.
    

    I installed 2 LasDrop seals on my boat this Spring.  One on the
    prop shaft and one on the rudder post.  I have a canted rudder that
    continually leaked water into the cockpit when motoring, regardless
    of how tight I cranked the stuffing box.  Using the Lasdrop seal
    has stopped ALL leaks, Period!  
    
    The concept is not new.  They have been using similar devices to
    seal shafts on motors in large machinery that pump liquids.  The
    application as a stuffing box is just another marketing of an old
    product.  But, boy is it a God-send from the old stuffing box.
    
    P.S. - The reduced drag on the prop shaft is said to conserve fuel
    and this is very important when you're offshore.
    
    Happy Sailing!
    
    

    I know all you folks are sailboat types, but I'd like to know if
    one of these LasDrops (or some variation thereof) would be suitable
    for my inboard ski boat (I can hear the boos and hisses from here).
    Where might I find such a device?  Thanks for any help.
    
    Happy Boating...  :-)
    
    					...Roger...
    

re .3:

If you will write on the blackboard 100 times

  *** I will NEVER, EVER leave a wake when passing a sailboat ***

then read on.



The Lasdrop is manufactured by the Lemania Company, PO Box 22491, 1777 
South East 15th Street, Fort Lauderdale, FL 33335, 305-523-1824. Local 
distributor is H&H Propeller Shop, One Essex Street Extension, Salem, MA 
01970, 617-744-3806. Special models are needed for speeds in excess of 
30 to 40 knots. Contact Lemania for information.

Alan

    RE .4:
    
    OK, I'll be a good boy!  But I figure that if I come whizzing by
    at about 40 there should be almost no wake anyway, right?  The problem
    is that I can't guarantee that the slalom skier I'm towing won't
    decide to get cute and hang a tidal wave over your boat with a major
    cut across the wake!!!   Mind you, I don't condone this action,
    at least with sailboats.  But canoes are a different story!  :-)
    
    Thanks for the info, Alan.  I'll definitely give Lemania a call.
    Could be "Adios" to a long-standing problem.
    
    					...Roger...

    P.S.  I knew you sailboats people weren't all fluttering in the
	    breeze! I know, bad joke!  :-)  :-)
    				.
    				.
    				.
    	 98  I will NEVER, EVER leave a wake when passing a sailboat
    	 99  I will NEVER, EVER leave a wake when passing a sailboat
    	100  I will NEVER, EVER leave a wake when passing a sailboat

       Whew!  Done.  OK?

    1 down 10e9 to go.
    
    nice work

    with half of my engine removed, I have a nice look at the stuffing box,
    leaking, leaking.....
    
    Alan, your LasDrop, still working fine ?
    
    Can you remember how much wear on the shaft was allowed, when you 
    installed it ? 
    
    Thanks, Peter

    I had a "PSS Shaft SEAL" on my previous boat and cannot understand how
    the old-style is still surviving.  The PSS/Lasdrop are much much
    better.

I have a Deep Sea Seal fitted on my new boat - which hasn't been launched yet,
so I can't vouch for its effectiveness from first-hand experience :-). However,
these things have been generally used for some time in the UK, and probably
elsewhere (maybe under a different name?). There is generally an advertisement
for them in the UK sailing magazines.

They are much as Alan has described for the Lasdrop, except that the moving half
of the seal is also in rubber bellows clamped to the shaft, so that shaft wear
is not a problem, unless it also includes deep longitudinal ruts in the shaft!
The spring in the rubber bellows provides the force holding the moving half of
the seal against the fixed half. Ideally, it is supposed to be water lubricated,
and as I understand it most builders assume that water flowing in through the
cutless bearing at the outboard end of the shaft will provide this. However, my
boatbuilder was apparently a belt-and-braces man, and has coupled up the water
inlet on the seal (normally left blanked off) to a T-piece on the engine coolant
feed so that water is fed into the seal under some slight pressure.

Apparently, when fitted from new, the price is very similar to that of a
conventional packed gland with screw-down greaser, with the advantage of not
needing any attention in use.

- Brian

re .7:

Peter,

Yes, our Lasdrop (one of the original design ones) is still working just 
fine after about 800 hours of use. The only attention I've given it has 
been to replace the rubber bellows once. There seems to be virtually no 
leakage. At least I haven't noticed any.

The sealing is between a delrin (or similar plastic) ring clamped into 
the bellows and a stainless steel ring clamped to the propeller shaft. 
There is an O-ring sealing the stainless steel ring on the shaft. As 
long as the wear on the shaft isn't enough to cause the O-ring to leak 
(this would be a lot of wear), there is no problem with previous shaft
wear. 

Based on our experience, I'd recommend a Lasdrop, PSS, or the similar
seal from yet another competitor. I've really not minded not repacking a
traditional stuffing box every year or so. I don't see the need for the
water injection used in the latest designs, at least on my slow speed
(~1000 rpm) shaft. It is just one more water hose that could (will
someday) fail. 

Alan

    thanks for the answers.
    	
    I will give it a try.
    
    Peter

I don't have a Lasdrop stuffing box but all of my stuffing box 
problems disappeared when I changed the bronze propeller shaft to 
stainless steel. In the past, I always had problems with the 
stuffing box leaking especially at the beginning of the season. I 
attributed it to verdigris building up on the shaft that caused 
the packing material to leak. With the new SS shaft, I never have 
to adjust the box.

Joe 

re .12:

Well, our traditional stuffing box always leaked more than our Lasdrop, 
even with a stainless steel shaft.

    For What It's Worth
    
    I have not had to adjust our convential stuffing box on Viking Rose for
    the three seasons that we have had her in the water (stainless shaft
    with bronze prop).  When under power the shaft produces one drip every
    nine seconds, which is exactly the rate that it should be.  There is no
    leakage when the prop is not turning.
    
    Friends of ours in Seattle had serious problems with their shaft seal
    system (I don't recall which one).  It seems that either system works
    well under some circumstances and has problems under others.  Any ideas
    why this is the case?  
    
    By the way, although it is very easy to adjust the stuffing box on a
    Westsail 42, I have not touched it since we purchased the boat.
    
    Cheers,
    
        Howard

    I have a Lasrop on my C+C29-2 with a Yanmar 2GM diesel.  The length of
    the shaft between the engine and the exit tube (shaft log?) on the boat
    is short.  Maybe a foot and a half.  The Yanmar is a real shaker,
    especially at lower rpm.  I installed a Lasdrop about five years ago,
    in order to avoid stuffing problems problems and to avoid periodic 
    adjusting of the stuffing box, since access to it stinks.  I have never
    gotten the Lasdrop to give me anything close to a dry seal.  As the
    engine shakes and rattles and rolls in its soft motor mounts, the
    Lasdrop gives some pretty impressive imitations of Old Faithful.
    
    A friend of mine has a brand new Yanmar 2GM in his Westerly GK29, also
    on a short shaft.  He's had some pretty impressive squirts, too, with
    the Lasdrop.
    
    Neither one of us has removed the Lasdrop, however.
    
    djc  

I am not sure just how close the Lasdrop design is to the Deep Sea Seal sold in
the UK, but there was a warning letter published last week in one of the UK
sailing magazines re the DSS.

The problem is that the two halves of the seal can stick together so strongly if
left motionless for a long period (like a winter ashore?) that the next time the
prop shaft turns it rips the neoprene boot rather than the two halves of the
seal sliding against each other. This can be embarrassing...

According to the letter, the manufacturer recommends that the seal is parted
briefly by hand to ensure that the halves are not stuck, but I do not remember
seeing anything of the kind in the instructions that came with mine.

Isn't technology wonderful?

- Brian