Screw drilled through hull bottomby Rudder. Post


KTMsailor
 

Nick,
Your advice is appreciated and I'll explore going that direction.  Your suggestion is way better than what I thought might be necessary.
I might add some JB weld around the area to seal it as well.

Thanks
Mark

_________________________________
Mark Wilkinson
Paddock Swimming Pool Company
15120-C Southlawn Lane
Rockville, Maryland 20850
ph. 301-424-0790, ext 250
fx.  301-424-0556
Cell: 301-580-2790
mwilkinson@...




From:        "nick walker" <hockeythumper@...>
To:        "C400@Catalina400-445.groups.io" <C400@Catalina400-445.groups.io>
Date:        12/28/2021 10:21 PM
Subject:        Re: [EXTERNAL] Re: [C400] Screw drilled through hull bottomby Rudder. Post
Sent by:        C400@Catalina400-445.groups.io



Hi mark,

The set screws are retaining bolts for the bottom rudder bearing. The bearings were originally fixed with countersunk screw from below the boat but the bearing came loose in some cases and this was subsequently changed to the method on your boat.

Ours were the original method and came loose but our owners manual had engineering drawings for the revised method and I have made the modification. I would suggest withdrawing the screws, clean up the threads and inject suitable flexibile, below water sealant in the holes and onto the bolts and reinstall. Make sure you snug them up sufficient but don't overtighten. Hope this helps.

 Regards,

Nick. Divided Sky #232



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From: C400@Catalina400-445.groups.io <C400@Catalina400-445.groups.io> on behalf of KTMsailor <mwilkinson@...>
Sent:
Wednesday, December 29, 2021 5:42:40 AM
To:
C400@Catalina400-445.groups.io <C400@Catalina400-445.groups.io>
Subject:
Re: [EXTERNAL] Re: [C400] Screw drilled through hull bottomby Rudder. Post

 
My analysis that the PO drove screws thru the bottom of the hull to hold the battery box down was erroneous.  The boat is currently on a hard so todayI went into the Port lazaret at the stern to  remove the battery remove the battery box. The rusty screw identified earlier did not pass through the 2 x 2
The 2 x 2 was actually bedded with some sort of sealant and the screw did not penetrate the hull.  But I did find a source of the leak(s).  At the very base of the rudder post on either side I found what looks like a hole drilled in the rudder post at the very base just above the inside surface of the hull (one on the starboard side and one on the port side) what appeared to be some type of Apoxsee or putty with a nonferrous screw going to the center of it. Both “plugs” Showed extensive discoloration where they had been leaking.  My best guess is that either Catalina or the previous owner elected to drive the screws in to hold thy rudder bushing in place while the rudder was being worked on but this is just a wild guess.  

Now  I need to determine how to fix this mess.  Do I remove the screw drill out the epoxy and re-epoxy it?  Are the screws holding the bushing in place and keeping it from dropping down to the top of the rudder blade? Do I need to drive wedges on top of the rotor blade to hold a bushing up while I repair the leak?
I have attached several photos below and hopes that somebody can tell me if they’ve seen this before and a best fix
thanks Mark

--
Mark Wilkinson

Great Escape

400 MK II- Hull # 312


--
Mark Wilkinson
Great Escape
400 MK II- Hull # 312


Ken
 

Mark,

Using JBWeld could make renewing the lower bearing somewhat difficult in the future.  The key point in fixing the lower bearing is to not use too long of a lag screw that the screw reaches the rudder shaft.  You may want to go up a size on the lag screw but not longer and 4200 or sikaflex is all you need to keep things watertight.  

If water was coming in from that hole it's my impression that someone has overtightened the screw in the past and reached the rudder shaft where the water is or your lower bearing is already loose in its mount and either needs to be rebedded or renewed.


KTMsailor
 

Ken
There appears to be some light gray looking Apoxsee about the diameter of a nickel surrounding the non-ferrous screw or lag bolt that you’re talking about
I was thinking about trying to put some sealant around that material in case it’s separated from the rudder shaft tube
I won’t compromise ahead of the screw I’ll make it extractable why not coding the head or immediate perimeter around the screw head
Your advice sounds sound I’ll get some 4200 and take care of this
Thanks again
Mark


On Dec 29, 2021, at 11:05 AM, Ken <kdg_1@...> wrote:

Mark,

Using JBWeld could make renewing the lower bearing somewhat difficult in the future.  The key point in fixing the lower bearing is to not use too long of a lag screw that the screw reaches the rudder shaft.  You may want to go up a size on the lag screw but not longer and 4200 or sikaflex is all you need to keep things watertight.  

If water was coming in from that hole it's my impression that someone has overtightened the screw in the past and reached the rudder shaft where the water is or your lower bearing is already loose in its mount and either needs to be rebedded or renewed.
--
Mark Wilkinson
Great Escape
400 MK II- Hull # 312