30 foot sailboat, deck glassed to hull.
Toerail leaked allowing water to balsa core of deck causing no more core.
I've removed the toerail (teak) so I have access to the moist stuff
that remains.
I've dug and blew that out and let things dry and now I'm ready to
backfill.
I need to shoot whatever I use up to six inches in. Epoxy would be
the best but how do you mix and get it in to something to inject it?
One of the sikaflex products would probably work if I knew which to
use. I'm thinking it can't be anything compressable as things need to
bottled thru it!
I'm now open for ideas!
Gordon

On Sun, 08 Jul 2007 19:23:31 -0700, Gordon wrote:


30 foot sailboat, deck glassed to hull.
Toerail leaked allowing water to balsa core of deck causing no more core.
I've removed the toerail (teak) so I have access to the moist stuff
that remains.
I've dug and blew that out and let things dry and now I'm ready to
backfill.
I need to shoot whatever I use up to six inches in. Epoxy would be
the best but how do you mix and get it in to something to inject it?
One of the sikaflex products would probably work if I knew which to
use. I'm thinking it can't be anything compressable as things need to
bottled thru it!
I'm now open for ideas!
Gordon

You aren't going to like this at all but the only way to be 100% sure
you have completely fixed the problem is to cut the deck. I had a
similar problem except the core was plywood and after messing around
with things for some time I finally cut a section of the deck skin off
and discovered that the core was wet for a much greater area then I
had anticipated.

Having said that if you are intent on filling with epoxy then the
usual method is to drill holes literally all over the area that needs
to be filled. Use "laminating" resin as it flows easier and start
pouring mixed epoxy in the lowest hole. When the epoxy reaches a
higher hole stop (stick a cork in the lower hole). As soon as the
first batch hardens enough that it won't flow start pouring into the
next higher hole, and so on. Fill from the bottom up to avoid trapped
air.

Don't worry about the holes, since you have (hopefully) dug out all
the old mushy core you will end up with a solid epoxy deck. Just sand
the filled holes fair and paint.

Do not plan on pouring the entire deck full of epoxy at one go. Epoxy
gets hot as it cures and more epoxy gets more hot. I doubt that you
will set the boat on fire but it is certainly possible to get some
serious bulging and warping of the deck skin and trying to fix this
problem after you have poured the deck full of epoxy is not really
something you want to do. Take it easy, a little at a time.

Finally, Epoxy is expensive and you are going to use quite a bit for
this project. Polyester is much, much, cheaper. However, epoxy hardens
slowly and you have 20 - 30 minutes to work with it before it "kicks".
Polyester sets up much faster and if you use it you have much shorter
time to work before things go solid. People will tell you that epoxy
is the only way to go as it is a much better glue and this is true. Do
try to use epoxy if possible.

If you use epoxy mix it exactly as the directions tell you to. If you
want different properties (faster/slower hardening, etc.) you can buy
them, don't try to mix a little more or a little less hardener in the
epoxy. You can get away with this to some extent with polyester but
don't try it with epoxy. The hardening process of polyester and epoxy
are two totally different chemical processes.

Do not try to "thin" epoxy. People will tell you to pour acetone,
thinner, gasoline, snake oil, whatever, in epoxy to thin it. Don't!
There have been any number of tests carried out on thinned epoxy and
anything you can buy to thin epoxy results in a weaker bond.

Good luck with the project.

Bruce in Bangkok
(brucepaigeatgmaildotcom)

--
Posted via a free Usenet account from http://www.teranews.com

Bruce wrote:

On Sun, 08 Jul 2007 19:23:31 -0700, Gordon wrote:



30 foot sailboat, deck glassed to hull.
Toerail leaked allowing water to balsa core of deck causing no more core.
I've removed the toerail (teak) so I have access to the moist stuff
that remains.
I've dug and blew that out and let things dry and now I'm ready to
backfill.
I need to shoot whatever I use up to six inches in. Epoxy would be
the best but how do you mix and get it in to something to inject it?
One of the sikaflex products would probably work if I knew which to
use. I'm thinking it can't be anything compressable as things need to
bottled thru it!
I'm now open for ideas!
Gordon



You aren't going to like this at all but the only way to be 100% sure
you have completely fixed the problem is to cut the deck. I had a
similar problem except the core was plywood and after messing around
with things for some time I finally cut a section of the deck skin off
and discovered that the core was wet for a much greater area then I
had anticipated.

Having said that if you are intent on filling with epoxy then the
usual method is to drill holes literally all over the area that needs
to be filled. Use "laminating" resin as it flows easier and start
pouring mixed epoxy in the lowest hole. When the epoxy reaches a
higher hole stop (stick a cork in the lower hole). As soon as the
first batch hardens enough that it won't flow start pouring into the
next higher hole, and so on. Fill from the bottom up to avoid trapped
air.

Don't worry about the holes, since you have (hopefully) dug out all
the old mushy core you will end up with a solid epoxy deck. Just sand
the filled holes fair and paint.

Do not plan on pouring the entire deck full of epoxy at one go. Epoxy
gets hot as it cures and more epoxy gets more hot. I doubt that you
will set the boat on fire but it is certainly possible to get some
serious bulging and warping of the deck skin and trying to fix this
problem after you have poured the deck full of epoxy is not really
something you want to do. Take it easy, a little at a time.

Finally, Epoxy is expensive and you are going to use quite a bit for
this project. Polyester is much, much, cheaper. However, epoxy hardens
slowly and you have 20 - 30 minutes to work with it before it "kicks".
Polyester sets up much faster and if you use it you have much shorter
time to work before things go solid. People will tell you that epoxy
is the only way to go as it is a much better glue and this is true. Do
try to use epoxy if possible.

If you use epoxy mix it exactly as the directions tell you to. If you
want different properties (faster/slower hardening, etc.) you can buy
them, don't try to mix a little more or a little less hardener in the
epoxy. You can get away with this to some extent with polyester but
don't try it with epoxy. The hardening process of polyester and epoxy
are two totally different chemical processes.

Do not try to "thin" epoxy. People will tell you to pour acetone,
thinner, gasoline, snake oil, whatever, in epoxy to thin it. Don't!
There have been any number of tests carried out on thinned epoxy and
anything you can buy to thin epoxy results in a weaker bond.

Good luck with the project.

Bruce in Bangkok
(brucepaigeatgmaildotcom)



-------------------------------------------------------

As an epoxy professional and vendor, I wanted to expand on what Bruce
(see above) said. He is pretty much 100% on the mark. Just two things
to add. Use an epoxy that will bond to wet surfaces (email me) and is
thin and watery to start with.

Bruce's comments about the thinning. Don't thin because the solvents
have no place to evaporate away to (being in an enclosed area). This
could be an explosive issue.....

squirt the epoxy in - folks use pastry bags and rubber tubing, squeeze
bottles, etc. - when done place weights on the deck to hold it down
while the epoxy sets.....

cheers!

paul oman
progressive epoxy polymers

Gordon wrote:

30 foot sailboat, deck glassed to hull.
Toerail leaked allowing water to balsa core of deck causing no
more core.

snip the balsa deck core story

1)My guess is you are looking at a 2-3 year project working by
yourself and perhaps a part time helper.

2) When you decide to sell, you will NOT recoup your investment in
replacement materials.

The only way to do this job is to cut away the top skin, section by
section, dig out the balsa, most of which will be wet, then replace
using Divinycell foam.

Once foam is in place,(epoxy & micro-balloon putty), then 2-3 layers
of DB240, (24OZ double bias,knitted glass), and laminating epoxy.

My guess is that material costs will be about $10K without further
cost increases which are on the horizon.

Think I would look long and hard at taking a chain saw to the boat and
look at something else.

$10K should get a pretty decent used boat these days.

Lew

On Jul 8, 10:23 pm, Gordon wrote:
30 foot sailboat, deck glassed to hull.
Toerail leaked allowing water to balsa core of deck causing no more core.
I've removed the toerail (teak) so I have access to the moist stuff
that remains.
I've dug and blew that out and let things dry and now I'm ready to
backfill.
I need to shoot whatever I use up to six inches in. Epoxy would be
the best but how do you mix and get it in to something to inject it?
One of the sikaflex products would probably work if I knew which to
use. I'm thinking it can't be anything compressable as things need to
bottled thru it!
I'm now open for ideas!
Gordon

I had the same exact project on my boat. I removed the toerails and
dug out the balsa through the bolt holes and let it dry. Or at least
I thought I did. I cut off a section of deck skin through six bolt
holes and discovered that the rot was more extensive than I thought.
I ended up using a 4 1/2 inch angle grinder with a cut off wheel and
just cut right down the length on either side of the bolt holes , bow
to stern. Essentially cutting out a 1" wide 35 foot long section of
deck skin. I then scraped and out the remaining balsa that remained
in the channel.

For a filler, because of the better access, and no need to inject
filler into small holes, I mixed up epoxy resin with fiberglass cloth
strands and troweled it in. The fiberglass cloth strands were from
cut up matte and cloth on a paper cutter. Strands were about 1/2 inch
long or so. I have found this to be a much stronger filler material
than most commerially available "powder" fillers.

I sanded it level, faired it, painted it, redrilled the toerail
holes, and reattached the toe rails

It came out well and I can't think of any other way I could have done
it better in retrospect.