Conference unifix::sailing

Oy vay! You do have a major problem. First, I think that the WEST folks
do telephone consulting. I'd call them. One of their newsletters had a
article describing repairing the delaminated deck of a Swan by drilling
holes and injecting epoxy. The amount of work was absolutely staggering.

However, if the balsa in your deck is wet and rotten, injecting epoxy 
isn't likely to work very well. The strength of a cored deck is partly 
due to its thickness -- stiffness increases with the cube (I think) of 
the thickness. Simply adding more layers of fiberglass (or whatever) 
will probably not restore the original stiffness of the deck. Plus, you 
will add a lot of weight to the deck, which is not desirable.

Back to the Swan: at the end the owners concluded (as I recall) that it 
would have been better to cut away the top skin of the deck, remove the 
balsa wood, install new balsa (or airex or whatever), and laminate 
a new top skin. This is, in fact, what I'd suggest you do. The work 
could be done in sections or small areas at a time. This would make the 
work easier and also make it easier to maintain the contours and 
fairness of the deck. Our Valiant had some delaminated areas in the deck 
(manufacturing defect) that were repaired this way several years ago. 
You can't tell where the top skin was cut away and the repairs done.

Practical Sailor has also briefly discussed this problem from the 
perspective of having the work done. The unpleasant conclusion was that 
having a boatyard do the repairs would likely cost far more than the boat 
is worth. The materials to do the repairs won't be inexpensive, but 
labor is another story. Only a few square feet of our deck needed 
repairs and then, of course, all of the non-skid areas had to be painted 
to hide the repairs. The labor bill was $4000 or $5000 back then. Other 
estimates for the same work were as much as three times higher.

Oh yes, you might look at Alan Vaitses' book on repairing fiberglass 
boat. He discusses repairing delaminated decks.

With sympathy,

Alan

Something similar to this happened to a friend of mine.  The cost of repairing
the delamination came to more than his 21 year old boat was worth--as Alan 
suggested may be the case with your boat.  Given the state of the used boat 
market, perhaps you're better off looking there instead....I know it's hard to 
say goodbye to an old friend...

F.

    
    
    	Hmmm... if these are only side decks, not deckhouse, you're only
    talking a foot or so wide by 4 or so feet??? I wonder if peeling back
    the top glass, digging out the rotten stuff, replacing with Airex or
    some such, then some prefab nonskid? Maybe worth a shot, especially if
    you don't have a buyer banging down your door.
    
    	Unless, of course, this area contributes to integrity/rig strength.
    I played with some freebie material a while back, Nomex? I think,
    fixing a rotted dinghy (glassed over mushy nonmarine plywood) and the
    seats I installed were, at about 3/8", the strongest part of the boat.
    Yeah, big deal, I'm comparing to something like gelcoat over wet
    cardboard...
    
    	Anyway, might be worth playing with. 
    
    	New England Plan: 6 months to play, 6 months to fix...
    
    	Scott.

    Water logged balsa cores are a common problem with the kind of boat I
    have  - an Etchells.  Frequent relocation of deck mounted hardware
    without careful filling of the resulting holes is the most frequent
    cause.  Also the light construction and the general abuse the boats get
    from hard racing don't help.
    
    Here's what most of the owners do when they can't stand the sponginess
    any more:
    
    1.  Outline the area of damage and extend them so you have reasonably
    rectangular sections to work with.
    
    2.  Get a router, set the depth to penetrate the deck's top skin of
    fiberglass.  Route along the outline you've created in (1).
    
    3.  Peel back the layer of fiberglass over the damaged area.
    
    4.  Scoop out the waterlogged balsa.
    
    5.  Clean off the exposed surface of the bottom skin that's now
    exposed.  Glass over any holes or thin areas.
    
    6.  Get enough new Balsa core to replace what's been taken out and glue
    in place with epoxy resin.
    
    7.  Bevel back the fiberglass surrounding the new core.
    
    8.  Laminate a new topsskin on, replicating the original layup.  This is
    usually a layer of mat and several layers of cloth.  You can tell by
    inspecting the layer that was removed.  You'll probably want to build
    up slightly above the surrounding level.
    
    9.  Sand everything flush and smooth.
    
    10.  Paint with polyU or gelcoat.
    
    11.  Tape off what you don't want to be non skid.
    
    12.  Mix non-skid granules in the same paint used before and apply to
    the taped off area.
    
    
    If you have molded in non skid, the repair won't look like the
    original.  But if you're careful, it'll look OK.  Or you can paint and
    re-nonskid the whole deck.  This isn't rocket science but it is very
    time consuming.  Figure on 5 - 8 days of work.  Depends on how neat you
    want to be.  About $300 for materials should be enough.  Definitely a
    character builder.  
    
    Hope your bottom's not blistering too.
    
    - gene

    We had the same problem on our ( then ) 17 year old Scampi. The
    solution was to remove the inner skin ( i.e. the cabin head-lining )
    in large panels and scrape away the waterlogged foam ( not balsa in 
    this case ). This was then replaced with new foam that was glued into
    place and the inner skin was then glued to that, and held in place by
    props until it dried. The joins were then covered by wooden strips.
    
    To prevent further problems, we then painted the deck with epoxy paint,
    and sealed any possible gaps. 5 years later, things are all OK.
    
    The work was all done profesionally ( by the Elephant Boatyard, for
    those reading this in the UK )
    
    Chris
    	

See Chapter 5 in The Fiberglass Boat Repair Manual by Allan H Vaitses, 
International Marine Publishing Co, 1990. He points out that while you 
can replace the deck core from underneath, overhead laminating is very 
difficult to do properly. I wouldn't even attempt it, for fear of 
dripping resin in my eyes if for no other reason. 

    reg alan and gene advise
    
    I tried that process on Steel Strings this past spring.... after first
    getting the estimate from a fibreglass guru.  The boat wasn't worth the
    price he was asking and he knew it.  His advise was to try it myself.
    
    It was painstakingly slow to do.  Didn't want to screw it up too badly
    and didn't want to take out more than was necessary.  Cutting the first
    slice into the deck was about the hardest thing.
    
    The results are great!  Stiff deck and a smooth surface.  I used BONDO
    rather than balsa as a filler.  Advise was that bondo would be easier
    to work with, inasmuch as the balsa is not just balsa but  is really
    heavily impregnated with resins.  I think I went through 3 cans of the
    stuff.  Got to work quickly, though.
    
    Do a section at a time.  Drying it out once opened up is made easier by
    a hair drier.  
    
    The pumps for the resin and hardener were indespensible.  The materials
    are quite goopy.  The pumps made the mixing quite easy and reduced the
    chance of getting a 7x1 or a 3x1 mix.

    First, let me thank you all for the responses. And Sympathy.

    I have a question on the strength vs. flexibility of delaminated
    structures. How much strength has a delmainated deck lost? 80%, 50%,
    more? If it's not that much of a loss, then i can probably live with
    the deck as it is. I only use Cachalot for bay and near-costal cruising
    (Long Island to Boston), and if i start getting lotsa green water over
    the foredeck, the fertilizer has already hit the ventaliting device by
    that time. While flexible decks detract from resale value, the best i
    could hope for at this time is $4k - $5k anyway.

    I think the foredeck may not be laminated, as it was a little squishy
    when i bought the boat in '79. I don't think it's gotten too much worse
    since, but i can't really remember. The side decks, however, used to be
    nice and solid, and now have many squishy areas.

    Gene: how big an area(s) did you repair using your outlined method? I
    can see it working on small (less than 100 square inches) areas, but
    does it scale up to larger areas (e.g. 2-4 sq ft)? At any rate, using
    bondo or ballons in epoxy as the filler seems like a win if one minds
    the time before it sets up.

    However, i'm still interested in simply layering up to 1/4" of
    laminates on all the foredeck and most of the sidedecks. I'll contact
    WEST and see what they say and report back to this note. If the weight
    is kept to less than 2 lb/sq-ft then the total new weight would be in
    the 100 lb range, and that's not too much for a non-racer that already
    displaces about 4000 lbs. loaded

    We'd like to get a couple more safe years out of Cachalot, and still
    interest someone to take it off our hands at that time. So  although i
    could just live with it, maybe a little work now might save more down
    the road.

    tnx,
    paul

    To answer .8's question on the size of the area repaired - about 6 sq.
    ft. were fixed this way.  Some owner have done their whole decks - 20
    sq. ft. this way.  For a small area, a utilty knife run back and forth
    around the affected area is enough to pentrate the top skin.  Just cut
    a rectangular section using a straight edge for a guide.
    
    Strengthwise, I've forgotten the details but isn't the stiffness of the
    deck exponentially proportional to the thickness?  If the core's gone
    so isn't the thickness. My guess is a lot of the strength's gone. 
    Whether that means anything or not is debatable.  One of the oldest,
    softest Etchells had an excellent record in all kinds of conditions
    this year.  But it can be disconcerting to feel the hull working in the
    waves.
    
    I've used filler on small sections that needed recoring but hadn't
    thought of trying it on large sections.  But if it works OK, it will be
    a lot easier to obtain than balsa core.  
    
    Because the stiffness of the deck is so dependent on thickness, it may
    take many layers of add'l glass to restore integrity if the old core is
    left in place.  Also, rotted core tends to liquefy and ooze out at
    random places.  The accompanying smell can also be real fragrant.  
    
    This isn't so much a high skill undertaking as it is a high aggravation
    one.  One thing to check out with the poor economy is free lance help
    from former boatyard employees.  
    
    - gene 

    Our repair ( the one done from inside ) covered the whole foredeck
    ( from the mast to about 2 feet from the bow ), and the top of the 
    coachroof ( which is very wide on a Scampi ), right back to the
    companionway.
    
    The cockpit floor had also gone soggy, but this wasn't laminated, so
    was reinforced with a piece of marine ply epoxied on the underneath.
    
    If your balsa or foam filling is soggy, try and make sure that the
    leak is fixed before it is all put back together.
    
    Chris
    

    I repaired a one foot sq area on my boat.  I didn't want to pay the
    yard to do it.  When I purchased the boat I had the yard do a similar
    size spot for aroud a grand.  The work was hot, dirty and for a large
    area this wasn't feasible or relieable working overhead.
    I wouldn't come from the top because you will never get a good finish
    for a large area.  If I had to do it I would consider the following.
    1. If the deck is screwed on as many are, disasemble it and flip the
    cabin top.
    2. If the keel can be removed flip the whole boat.  
    This may seem extreme but it is a much quicker working and cheaper if
    you pay a yard to do part or all of the work.
    I cut through the glass with a carbide ?? disk on a 1/4"drill and 
    removed the core.
    Not knowing the value of the boat I'd estimate its not worth the effort.
    

re .last:

Once you've replaced the core material and relaminated a new top skin, 
you needn't worry about matching the patch to the rest of the deck. 
Just paint the entire deck, which isn't difficult -- I've been able to
get a good smooth finish with a white two-part polyurethane applied with 
only a roller. Removing a deck or rolling a boat upside down would be 
vastly more work for any boat larger than a daysailor. 

With a little luck, you can cut away only non-skid areas, which means 
only repainting only non-skid areas, which is especially easy since 
you're not trying for an unblemished, glossy finish. Our deck was 
repaired this way. The non-skid was painted white to (almost) match the 
original gelcoat. I now wish we'd had the non-skid painted light gray to 
reduce glare from the sun. 

    re: skill -
    
    hey, i'm a no skill guy.  this took time and patience, rather than
    initial skill.  got to take less and less time, the more i did, though.
    
    good way to become one with your ship, into the karma of the sloop, so
    to speak.
    
    ron

    Again, thankx for the ideas.

    Although a byproduct of Bob was higher boatyard employment, the idea of
    trying to find a freelancer sounds reeeeal good.

    The leaks that caused the delamination have been fixed, but fixing them
    is a process, not an event. That is, deck fittings need checking and
    often rebedding almost yearly, or more often. For balsa-core decks
    owners, i'd suggest Preventative Maintenance often. 

    The non-skip is molded into the deck, and is fairly widespread. This
    will make things a little messy on the finish job, but if Alan can dare
    paint the deck on his beautiful Valiant, i can try it on my 26 year old
    Ariel.
    
    re: skill - i have moderate skill, but not great. However, time and
    a workarea may be tough. The comment someone voiced (typed?): "First
    build a boathouse..." may come true to a certain extent. The boat's in
    the backyard, so a few PVC pipes, a new tarp  and a space heater may be
    enough.

    If WEST doesn't have a better suggestion, i might be apeeling....

    tnx,
    paul    

Will the following approach reduce the risk of water getting into the core?

Wherever a screw is put into (or through) the deck, drill a oversize hole, fill
with epoxy, drill hole through epoxy, put screw into (or through) epoxy.

I need to rebed my stanchions, and I'm thinking of doing it this way.


Questions:

Does this work?

How much should I oversize the hole?

Will this weaken the screw holding power? (How about for a thru bolt? How about
with a backing plate?) 

Is epoxy the right material? With a filler?


I have two areas on my boat that might have the beginnings of delamination
problems: On the coachroof, there is an area about 1 sq ft, where there is
a crackling sound (fiberglass strands breaking?) when I walk on it. The
deflection does not seem to be excessive. If there's water in there, it must
have gotten in through grab rail screws. (The surveyor found no evidence of
moisture when I bought the boat 6 months ago.) Is it possible to have
delamination without moisture?

At the emergency tiller access in the cockpit floor, there is a 8" circular
cutout in the plywood core around the rudder post. There is some rot at
the forward end of this cutout, perhaps along a 2 inch section of the
perimeter. How can I guesstimate the distance that the moisture extends
into the plywood? I'd like to simply make a bigger cutout, and replace the
access hatch with a larger size. I'll seal the plywood edge with epoxy before
I put the new access hatch in.

--RS

re .15:

Yes, making epoxy bushings is, I think, the right approach. On our boat, 
and I suspect it is typical, the top (outer) layer of deck laminate is
thicker than the bottom (inner) layer. I have managed to get to the 
underside of the deck for most of the hardware fastening holes. I use a 
3/4" to 1" hole saw to cut out the inner laminate and balsa wood. This 
leaves a 1/4" hole through the outer laminate. Using epoxy, I then glue 
a small piece of fiberglass cloth over the hole from the underside. Once 
the epoxy hardens, I fill the hole with slightly thickened epoxy from 
above. Surprisingly often, quite a lot of epoxy is required as the epoxy 
flows sideways into any delaminations between the balsa and deck 
laminates and into any voids in the balsa core. When the epoxy hardens, 
you have a solid, well-sealed epoxy bushing in the deck. Now if any 
water leaks around the hardware mounting screw, the water won't get into 
the deck, nor will will the deck be crushed from tightening the nuts 
onto the screws. Be sure to use a backing plate or large fender washer 
on the underside. If you absolutely cannot get to the underside of the 
deck, cut the hole from the top. No prizes for guessing that this is a 
tedious, time-consuming procedure. Also, be sure to fill the holes on a 
cool day so that the epoxy doesn't cure too quickly. I use slow hardener 
and even then I've a couple of times had to cut out the too-quickly 
cured bushing and do the job over. In direct sunlight a deck gets very 
warm even on a cool day.

I would never ever use screws to hold anything carrying any load (and
most especially stanchions, blocks, cleats, etc) to a fiberglass
laminate -- always through-bolt everything. I've had to cut a number of
holes in our deck liner to accomplish this. So far I done bushing for
all of the deck hardware (including handrails) except the genoa tracks. 

Yes, it most certainly is possible to have delamination without
moisture. Balsa wood isn't terribly strong, and the laminate to balsa 
bond does fail. Expansion of the deck on very hot days (especially if 
the boat is air conditioned below) can even do it (or so I was told by 
the manager of a reputable boatyard). Excessive flexing of an
insufficiently stiff structure will certainly do it. 

Re your rotted plywood: I don't know of any way to estimate how far the 
rot does. Keep cutting until you find the end of it.

    Paul, go for the repair of the non-skid , you can get over to the
    sides under the deck also.
    
    Must have a core material.   My 1967 Triton has the old basket
    weave non-skid painted with poly and griptext.   (use a brush,
    as the boat yard did on mine, keeps the griptex from pulling
    out of the paint when you roll)
    
    Do it from the top.     Allan is right on epoxy plugs, and for
    heaven sakes DON'T use screws for hardware, an accident waiting
    to happen !   (got to watch a runabout being pulled off the putty
    once, when the cleat pulled out watch out !  40% stretch in nylon
    coming back with a metal piece on the end , no one got hurt)
    
    I did see one deck removal, the Yard manager at a boat yard who
    bought an old Chesepeak 32, bad deck, removed it all in ONE piece
    flipped it over , cut off the inner liner and put new core and
    liner back in.   What a job !
    
    The paint and griptex will hide any small flaws in the top glass
    work, so I'd go for it, at least on the side decks.  (I assume
    you have some hardware mounted there, it's in doubt how it will hold
    if it's that punky)
    

> for heaven sakes DON'T use screws for hardware

lest my reputation should be ruined by the thought that I might be using mere
*screws* for deck hardware, I'd like to clarify that I was speaking of
non-critical stuff like dodger snaps. Unfortunately, there are more holes
in my deck from this sort of gear, than from *real* hardware :-(

The process described by Alan for through-bolts sounds excellent, but presumably
is overkill for the small screw holes. Any suggestions for dealing with these?

--RS

re holes for small screws:

OK, yes, there are times that screws are an appropriate solution. I'd 
suggest drilling a hole 3/8 to 1/2 inch in diameter or as large as
possible (ie, one that will be hidden by whatever you're attaching to
the deck) through the top layer of deck laminate and the core material.
Fill the hole with slightly thickened epoxy so that it is flush with top
surface of the deck. After the epoxy has hardened, drill a screw pilot
hole with a diameter equal to or slightly larger than the thread root
diameter of the screw. 

Alan

    re: .18
    On dodger screws I have used a dab of RTV on the end.   Not as good
    as the epoxy route but keeps the wet out.
    
    I fill in all the old holes with epoxy and pigment, when no longer
    needed.  (since the boat is painted, deck and hull I now just touchup
    with AwlGrip)