[Rhodes22-list] hull deck joint reseal questions

Mon Apr 29 13:07:58 EDT 2013

I tried various sealants and found that after a few years they all began to
leak as it is difficult to remove the old stuff and to get the new stuff in
there. 

My hull - deck join used rivets except where the chain plates were attached.
I expect that your join is also riveted but they might not be very visible.
As I recall the rivets were spaced very far apart and seemed intended to
hold the parts together before chalking the joint and then relying on the
rub rail screws to compress the joint. I suspect that the leak was due in
part to movement developing at the join and that does not make me feel
comfortable. My boat is old and the deck did not come off over 40 years  but
it seemed to me that the join construction was not adequate. Again, my boat
is a 74 and there have been a lot of improvements since then so your
construction might be different.

I don't like rivets and much prefer bolts for strength but that will not
stop the leak. I decided that the best solution was to glass the join on the
inside from the bow to the aft end of the cabin. The cockpit can handle any
water that gets in through the joint and it would be too miserable to try to
glass the join in this area. It is my intention to add bolts every foot or
so before installing the rub rail. Had I not glassed the joint I would
probably put the bolts every 4 inches. That is probably overkill but I
always try to error on the ridiculous side. I don't want to rely on the rub
rail screws to do anything more than hold the rub rail on. I think I will
use 4200 and as few screws as feasible as screws introduce the possibility
of new leaks. As a further precaution I will probably seal the outside joint
with 4200 as well to keep bugs out. When I took my deck off I found that
flying ants had made their way up through the join and had nested in the
wooden deck core. 

Using 5200 is not advisable as that will make it extremely difficult to
remove the rub rail in the future without doing serious damage to the boat.

To glass the joint you need to remove the padded trim and then cut back the
liner lip to about 1" from the cabin top in order to get in with the cloth
and epoxy. I cut the lip back with a grinder (see picture). This also
removed the place where the trim cover pieces are screwed on so I plan to
epoxy some wooden blocks to the hull  where needed for that purpose. You
might also need to peel back or remove any hull covering near the join in
order to have an area to bond the class to. 

There was then a strip of thin plywood that the rub rail screws were
intended to bite into but the strips were delaminating and rotting in places
so I removed it with a chisel (see picture). I filled the area to be glassed
first with a thickened epoxy mixture so that I would have a smooth area to
lay the cloth.  Before it hardened  I applied  four layers of 6 oz. rovings
(see picture of the finished job). I don't know how adequate that is but
compared to nothing, it is a big improvement. In the end there are no leaks
and a much stiffer and stronger joint. 

The job is not particularly difficult but it is messy. It was also made
easier in my case as I had stripped the boat of all internal furniture/
bulkheads etc but I would think it could be done without removing
everything. Cutting off the liner lip makes a lot of dust so wear a mask and
cover everything. It is not a trivial job but on the other hand glassing
from the inside might make it unnecessary to remove the rub rail.  I found
that I could not remove my rub rail without destroying it so that adds to
the cost. You will need to grind off any screw tips so the glass cloth will
lay flat. I would not grind off the rivet ends however unless, as I am
doing, you will be replacing them with bolts. 

Another thought, I think it would be quite possible to drill out the rivets
and bolt the join without removing the entire rub rail if you remove the
black plastic bumper and then use flat head bolts into a countersunk hole to
bold right through the aluminium rail. Getting the plastic bumper  piece
back on properly will be a pain but there are some good instructions on You
Tube that shows you how to do this.

Graham Stewart

-----Original Message-----
From: rhodes22-list-bounces at rhodes22.org
[mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Mike C
Sent: April-29-13 10:47 AM
To: rhodes22-list at rhodes22.org
Subject: [Rhodes22-list] hull deck joint reseal questions

It looks like it's time to do a reseal on s/v Muireann's hull deck joint.
We get water in the hull when we've been "wave bashing".  I've searched the
archives and read what's there.  It's good stuff and I have a pretty good
idea of how to proceed.  I haven't pulled the rubrail yet, but I took a peek
at a section and discovered that instead of rivets s/v Muireann has screws. 
So one of my questions is "Should I plan on replacing the screws with
rivets?".  Another is "What diameter and length rivets?".  Finally the list
advice didn't mention how the old sealant is removed.  Is it simply
physically removed? Or is a solvent advisable?  As for caulk, one part
polyurethane was recommended in the archives.  Would 3M 4200 be a good
choice?  

Thanks for any and all comments and help!

-----
Mike Cheung
s/v Muireann
--
View this message in context:
http://rhodes-22.1065344.n5.nabble.com/hull-deck-joint-reseal-questions-tp45
504.html
Sent from the Rhodes 22 mailing list archive at Nabble.com.
__________________________________________________
To subscribe/unsubscribe go to
http://www.rhodes22.org/mailman/listinfo/rhodes22-list

For the list Charter and help with using the mailing list and archives go to
http://www.rhodes22.org/list
__________________________________________________
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hull - Deck join rebuild 2009 (3).jpg
Type: image/jpeg
Size: 40146 bytes
Desc: not available
Url : http://www.rhodes22.org/pipermail/rhodes22-list/attachments/20130429/26a1dda5/attachment.jpg 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hull - Deck join rebuild 2009 (5).jpg
Type: image/jpeg
Size: 41804 bytes
Desc: not available
Url : http://www.rhodes22.org/pipermail/rhodes22-list/attachments/20130429/26a1dda5/attachment-0001.jpg 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Hull - Deck join rebuild 2009 (6).jpg
Type: image/jpeg
Size: 34238 bytes
Desc: not available
Url : http://www.rhodes22.org/pipermail/rhodes22-list/attachments/20130429/26a1dda5/attachment-0002.jpg 