Posted by Patrick Weaver (patrick@…>)
Peter,
I
realize I never got back to you re: your core damage. This is usually a 3-step
process:
-
Getting the
core dry (duh)
2. repairing
existing damage
3. preventing
it from happening again
One of
the sites I have found helpful is www.Rotdoctor.com
I had
a project where I needed to create bullnoses on the front stairs of our
commercial townhouse. The previous owners just poured concrete into
straight-edged forms and the treads were too narrow. I chose to do this in wood
because if someone slipped on the stairs I didn’t want them cracking the
back of his/her head on a totally unyielding substance. I used Rot Doctor’s
penetrating epoxy for sealing the end-grain in all the lumber, their epoxy to
glue wood to wood, their Sonolastic caulk to glue the wood to the concrete,
their fillers too even everything out, then their primers, paints, and antiskid
to paint the stairs. It’s a year-old now and everything is holding
together remarkably well through rain, snow, sleet, changing seasons, and heavy
traffic. I used the same materials for a 3-season room I’m building which
has an exterior plywood deck. After a year things look great there as well—absolutely
no signs of moisture penetration.
This
summer I plan on using their materials on my 29 foot racing cat that has some
core issues on its decks. I have had the boat covered with lots of ventilation.
It’s been this way for three years while I finished the house and my
commercial building, so the core is dry. However, the decks on a racing catamaran
are picking up a lot of the load from the crossbars and the rig, so I want to
be sure everything is strong. Therefore, I still plan to cut through the top
layer of glass on my deck, lift off the glass, and then assess the core damage.
After repairing/replacing the core, I will refasten the top layer of glass to
the core using epoxy, vacuum bagging AND dead weight. Then I will repair the
seam using the Gougeon method of starting with wide glass at the bottom of the
repair and filling with successively narrower patches. My decks were already
painted, so I’m not trying to save a gelcoat. I was thinking of using Treadmaster
decking but with the economy so bad, I may wait to do that.
http://www.plastimousa.com/treadmaster.htm
The important
thing is to be sure to keep it from happening again by overdrilling any
mounting holes, filling them with epoxy and then drilling your mounting hole
through that epoxy. That way your core material is sealed and protected. Be
sure that when you rebed your track that you don’t crank down all the way
otherwise you’ll just force out all the caulk and you won’t have
any bedding left.
I
decided to do things this way after reading a fair amount from Tayana, Pearson,
and Tartan owners who have suffered similar issues (as do S2 owners) and I have
a 10 page Word document of notes from various sources including:
http://www.pearsonariel.org/discussion/printthread.php?t=43&page=2&pp=100
http://www.tartanowners.org/phorum/read.php?f=9&i=5&t=5
http://www.forums.boatdesign.net/printthread.php?t=7516
http://www.uscg.mil/d14/units/msohono/references/nvics/8-87.htm
I also
read the West System book on vacuum bagging (which I have done some of on my
sailing kayak) and found it to be a worthwhile investment (the real expense
being the pump, gauges, tubing, etc. Be aware though, you may decide you’re
ready to build a boat after reading the book!
There are
a lot of opinions on what sort of core is best. Ian Farrier recommends foam
sheets for building but that is because he has designed a system that makes the
building go faster with this material. His earlier designs have been built with
all types of materials. I have read arguments that say that foam core is strong
in compression but weak in shear while Balsa is strong both ways. Balsa
will rot if it gets wet but if you take adequate care, it shouldn’t get
wet. With that in mind, I’ve decided to go with Balsa as the majority of
my issues seem to stem from previous owners not taking care to see that they
sealed the core after drilling/cutting holes in the boat.
Remember,
when making a boat repair, take the time you estimate it will take and multiply
it by four. Now you have how long it will actually take. You should probably do
the same with the materials cost.
Hope
this helps. Whatever you do, avoid the temptation to leave it alone. Something happened
here to cause that water damage in the first place—it isn’t going
to go away by itself.
Patrick
-----Original Message-----
From: freedom21@yahoogroups.com
[mailto:freedom21@yahoogroups.com] On Behalf
Of Peter Devlin
Sent: Monday, March
31, 2008 5:38 PM
To: freedom21@yahoogroups.com
Subject: [freedom21] Re: Traveler
Track (correction)
Guys, Thanks for the
speedy and useful replies. Joe, did you have water
damage to the core around your traveler track? Did you repair it with
epoxy or balsa? Mine has dried, seemingly completely, and I am sorely
tempted to leave it alone.
\