[C320-list] Leak in bilge

[Bruce Heyman]

Allan,
I love that quote and your law.  I've found throught out my life that I've  
done most jobs twice, probably good thing I didn't choose to become a  
surgeon.  I've also found that when I've really screwed something up all I  
have to do is point out that Sailor Murphy is a permenant member of our  
crew.
Best,
Bruce
Somerset 671 SoCal

Bruce Heyman
(949) 289-8400
BruceHeyman at cox.net

-----Original message-----
From: "Allan S. Field" <allan.field at verizon.net>
To: C320-List at Catalina320.com
Sent: Sun, Jan 23, 2011 13:42:46 GMT+00:00
Subject: Re: [C320-list] Leak in bilge

Bruce - To paraphrase Winston Churchill, I can always be counted on to do
the right thing but only after I have tried everything else.  I call it
"Field's Law of Doing Stuff": If I have a 50/50 chance of doing something
right or wrong the first time, 90% of the time I will do it wrong the first
time!

As for the torque wrench, I could not get the bolts to stop weeping with the
boat in the water.  Of course it stopped with the boat out of the water
(grin!) but seriously, my memory is that I could not get the torque wrench
to "snap" which was telling me that I had not gotten the bolts to the right
torque.  At the end of the day, thank goodness this only has to be done once
and is not another opportunity for me to screw (pun intended) it up again! -
Allan

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Bruce Heyman
Sent: Saturday, January 22, 2011 8:40 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Leak in bilge

Alan,

Yikes.  I definitely would not loosen all of the keel bolts while the boat
is in the water; it will weep as you say.  

While I have deep respect for Gerry Douglas and he is an excellent naval
architect/engineer I don't understand the reason to be loosening all of the
nuts at once.  

The reason you loosen them before you tighten them is you want to make sure
they are able to move freely. Typically when you go to loosen them it may
actually take more than 235 foot pounds to loosen them because they are
stuck (just hope they are not galled).  Some people think that after you
clean them up you should oil them.  If you do oil them conventional wisdom
is that you should reduce the torque setting by 20% to compensate for the
reduced friction.

Weather you do this job on the hard in the water I would recommend against
loosening them all at the same time.  I've had to redo a couple of keel hull
joints.  They are typically bed with either 5200, epoxy or an epoxy paste.
The purpose of the bedding is to keep the keel bolts 100% dry as they are
SS.  SS degrades very rapidly if it is held in trapped water that can't get
oxygen.  If you only loosen one nut at a time you are less likely to disturb
the keel's epoxy/5200 "gasket".

As to why you couldn't get to 235 foot lbs when in the water vs. on the hard
I don't understand what was going on.  235 ft lbs is 235 ft lbs regardless
of where you are...the torque wrench just knows you got to push on it really
really hard, it doesn't know if the boat is in the water or on the hard.
You either have to push 235 lbs on a 1 foot wrench or 117.5 lbs on a 2 foot
wrench or find a pipe that makes the wrench 4 feet long and then you ONLY
have to push 59 lbs.  Be glad that Gerry didn't specify 1.5" keel bolts!

Glad you bilge is now dry!

Best,
Bruce
Somerset #671 SoCal



-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Allan S. Field
Sent: Friday, January 21, 2011 3:59 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Leak in bilge

Bruce - If you aren't a mechanical engineer, your prose below would fool me!
But I do think that one point is missing.  I remember Gerry telling us to
loosen all the bolts at one time then torque them down one at a time.  While
I don't begin to understand the physics of what you describe below (or
whatever science you are going by!), if I heard Gerry right, I have a hard
time seeing how one could get the keel bolts tightened to the proper load.
But if I heard Gerry wrong, then I accept what you say below at face value
only 'cause I don't understand hardly a word of it!

Now if wisdom is nothing more than what is left over after all the mistakes
have been made, let me now give you the value of my hard-earned wisdom.  I
loosened all bolts at one time with the boat in the water (note that I slept
through most science classes in school and totally failed to think this
through before starting...).  As hard as I tried with the torque wrench, I
could not get any bolt to 235 foot pounds.  So now I have all keel bolts
weeping instead of just the one I started with.  After hauling and blocking
the boat, getting the proper torque was a piece of cake and not a weep
since! - Allan

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Bruce Heyman
Sent: Thursday, January 20, 2011 1:28 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Leak in bilge

I'm not a mechanical engineer but this problem intrigues me.  I believe it
does not really matter if you tighten the keel boats in the water or on the
hard. As my brain at this point can only remember that in some point in the
distant past I took physics I hope I'm not totally botching the concepts.
In no particular order:

1) The keel bolts do hold the weight of the keel, but more importantly they
compress the area between the keel and the bilge putting the keel trunk in
compression.  
2) The high torque requirement, 235 foot pounds, is to perform item one
above and does so by stretching the stainless steel bolt.  Hard to believe
that a 1" SS bolt stretches but it does and I believe this would be called
preload. 
3) The bolt and nut is a machine that provides significant mechanical
advantage.  Basically the threads form an incline plane making it much
easier to turn the nut compared to the lateral forces generated along the
axis of the bolt.  Thank you Archimedes (wonder if he was a boater?). 
4) The torque measurement is not only a measure of the work done in the
machine (threads) but also the friction on the nut face and the surface of
the threads.  That is why it is important to take the nut off, clean both
surfaces and make sure they are dry and free of contaminants.
5) If the breaking strength of a 1" - 8 threads per inch bolt is 60,000 lbs
the clamping or preload would be 14,992 lbs when torqued to 249 ft LBs.
6) As our keels only weigh 4400 lb's this means that one bolt when properly
adjusted would be able to hold the weight of more than three keels.
7) As we have multiple keel bolts, all torqued to 235# the preload more than
swamps out the relatively trivial weight of a single keel.  I don't remember
how many keel bolts we have but if we have 6 then the total preload is a
staggering 90,000 lbs.  This is 20 times the weight of our keels.

Maybe I'm all wet (pun intended) but I believe you are free to torque your
keels in the water.  Furthermore it is safe to remove one nut at a time and
clean it up before you reinstall it and torque it to 235 ft lbs.

Bruce
Somerset #671 SoCal

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Allan S Field
Sent: Sunday, January 16, 2011 11:04 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Leak in bilge

Bruce - you are correct in that the Association has the torque wrench and
sockets to tighten the keel bolts. However, the boat must be out of the
water with at least 70% of it's weight supported by the keel. Think about it
- if the boat is in the water and the weight of the keel with a gravity
assist is pulling the keel down, what torque wrench and what sailor have the
strength to pull that puppy up?! In fact, the bolts first get loosened
before torquing. And yes, loose bolts do weep and need to be torqued after
the first year then never again, at least according to Gerry Douglas. -
Allan

Allan S. Field
Sent from my iPad

On Jan 16, 2011, at 1:27 PM, "Bruce Heyman"<bruceheyman at cox.net> wrote:

> Can be tightened in the water.  The Association has the equipment you need
to do this job.  I thought the manual said to tighten them after the first
year and then you were done forever.
> Bruce
> Somerset 671 SoCal
> 
> Bruce Heyman
> (949) 289-8400
> BruceHeyman at cox.net
> 
> -----Original message-----
> From: Kurt Budelmann <krbmd77 at charter.net>
> To: "Catalina320.org" <C320-List at Catalina320.com>
> Sent: Sun, Jan 16, 2011 18:02:06 GMT+00:00
> Subject: [C320-list] Leak in bilge
> 
> Hey, I am having a slow leak in the bilge right by the bilge pump.  No
collections of water fore or aft of this location.  Can water leak down from
top of mast?  Can water leak from the keel bolts?  Also there is a floor
joist crossing at that location but I can find no evidence of leaks from
ports.  I don't think keel bolts were ever re- tightened and the boat has
never been out of the water since original launch.  Can the bolts be
tightened in the water or does the boat have to be on the hard?
> 
> Kurt R Budelmann
>