On Mon, 16 Jul 2007 10:09:59 -0400, "mr.b" wrote:

2 questions.
Has anyone ever heard of this procedure being done from the interior
rather than the exterior of the boat?

Also, can anyone give a ballpark estimate as to the expected cost of
loosening the lead ballast on a fin-keel and re-sealing/repairing the
joint between the two?


I did extensive core replacement, but from above. Reasons:

1. Easier to work. Working fiberglass is hard enough without trying
to do it overhead.

2. My non skid areas were imbedded glass beads. Possible to repair
the non skid and blend it so the repaired areas were not obvious.

3. my boat was old enough to need a complete cat poly job anyway, so
no paint matching problems.

4. the heaviest structural part of the deck is the underside, that is
the heaviest glass thickness and heaviest woven roving. At least mine
was. I didn't want to disturb that.

5. when you put new core in, end grain balsa in my case, you want to
wet it in to both glass layers well and fully saturate it. Difficult
to do working over your head. But from the top, you can just lay it
in like slices of bread, cutting and trimming until you get it just
right, then begin the process of permanenetly installing.

6. I didn't want to cover or remove everything on the inside that
might be impacted by the work.

7. I didn't want to be enclosed with fumes, dust, etc.

8. In my case the core had gotten wet, and the water had frozen,
cracking the outer layer of glass and gel coat, so some repair from
the top was going to happen anyway.


On the second question, if the lead ballast is loose, it needs to be
adressed. If you have simply have a seam, but the lead keel is still
soundly in place, you don't need to remove it in my opinion. That was
the case with mine. I filled the crack with an elastic caulk at each
haulout, prior to painting. Did fine.

Frank

mr.b wrote:
2 questions.
Has anyone ever heard of this procedure being done from the interior
rather than the exterior of the boat?

Also, can anyone give a ballpark estimate as to the expected cost of
loosening the lead ballast on a fin-keel and re-sealing/repairing the
joint between the two?

I see you have many good replies, but let me add that duplicating the
non-skid is rather easy if you choose to do it from above. You make a
mold from the pre-repair non-skid and use that as a template for the new
gel coat. Were I do do it, I'd remove all non-skid left after the repair
and use the paint / sand route for the new non-skid.

Re-coring isn't simple or cheap so you need to evaluate the value of
your boat before and after the repair, but it's possible (like almost
anything marine).

I have also heard rumor of injections which will, in situ, repair
defective cores. I'd run those rumors down to earth before embarking on
such a task.

-paul

wrote:
On Thu, 19 Jul 2007 17:51:05 -0600, Paul Cassel
wrote:

I have also heard rumor of injections which will, in situ, repair
defective cores. I'd run those rumors down to earth before embarking on
such a task.

-paul

Those mythical injections are sold in the same aisle at FairyMart as the pills
that you drop in your car's gas tank that do a ring job.


In theory an extremely low viscosity hygroscopic compound will do the
job, but as you can note from my OP, I'm skeptical that such a compound
exists.

On Thu, 19 Jul 2007 21:05:04 -0400, wrote:

On 19 Jul 2007 19:42:04 -0500, Dave wrote:

On Thu, 19 Jul 2007 20:35:27 -0400, said:

In theory an extremely low viscosity hygroscopic compound will do the
job, but as you can note from my OP, I'm skeptical that such a compound
exists.

Hoo boy! Are you just a little skeptical about the tooth fairy as well? How
about the Easter Bunny?

Really!

Just for openers - if the balsa is still wet, why would it absorb something as
thick or thicker than the water that is already saturating it?

Um.....I think you need to look up "hygroscopic."

Um, I think you need to look up a lot of other terms, including saturated, and
blind faith. Wet moldy rotted balsa is not going to accept much of anything,
regardless of how much you wish it would. This idea of a miracle potion is not
new, and it has been proven to be a complete waste of time money and effort. It
simply doesn't work. If it did, thousands of boats with soggy core would have
been saved from the chainsaw. Show me ONE that has been saved by this method.

The problem is that by the time the decks get soft you probably do not
have any structural material, to amount to anything, left between the
upper and lower deck skins. What you have is a mush of rotted core and
nothing is going to give it any structural integrity. Of course, if
you catch the problem before the core actually rots and is simply
saturated with water there are a number of methods of attempting to
dry out the wet wood.

One can apply a vacuum and I even read an article about someone who
took the door off a microwave oven, disabled the door disconnect, and
laid it face down on the deck. The problem is that none of these
methods are very successful and can result in additional damage to the
deck..

The only real answer is to remove the core and replace it with
something. Whether this be wood, foam, or even epoxy resin, makes no
difference you must, somehow, provide a bond between the upper and
lower deck skins or you do not have the original designed deck
strength.






Bruce in Bangkok
(brucepaigeatgmaildotcom)

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

On Jul 17, 3:19 pm, "KLC Lewis" wrote:
"Bruce" wrote in message

...



On Tue, 17 Jul 2007 06:05:00 -0700, wrote:

On Jul 17, 6:23 am, "Roger Long" wrote:
"KLC Lewis" wrote

I've only seen it done from above, also. You cut out large sections of
the
deck at a time, remove the old core, replace it with new, put the top
back
on, glass it into place, Robert's your father's brother.

And how strong do you think those butt joints that used to be continuous
fiberglass are? This is an approach that is either going to look like
hell
and be strong or look great and be very weak. Take your choice.

It could be done right but I'm sure you could buy a comparable used boat
for
a similar price.

--
Roger Long

Wouldn't you grind out the joints and overlap the joints with new
glass ? That would be strong and look good. But it might be easier
to lay new glass over the whole thing.

Todd Smith

Normally if you butt joint you grind out a shallow vee nearly to the
depth of the original material and extending about 4 inches back from
each side of the joint. You then laminate in progressive widths of
cloth until you fill the vee. You have then effectively turned the but
joint into a continuation of the original material.

Bruce in Bangkok
(brucepaigeatgmaildotcom)

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

Ya, a bevel of about 12 to 1 or 16 to 1 -- the wider the better.



7 to 1 is the recommendation from West. If both sides beveled to meet
nothing in the middle, only half as wide overall.

In polyester.

I did a thru hull as per, worked fine, was invisible under paint.

Terry K

"Terry K" wrote in message
ups.com...

New polyester resin is a poor bond to old polyester resin at best. I hope
the repair holds for you, but you may want to consider redoing it with
epoxy.

On Jul 20, 7:43 pm, "KLC Lewis" wrote:
"Terry K" wrote in message

ups.com...

New polyester resin is a poor bond to old polyester resin at best. I hope
the repair holds for you, but you may want to consider redoing it with
epoxy.

Naw, the boat was burned by vandals in the yard. I did beat the
speedo wheel in to drain the hulk.

Beat as I did, I was not able to make the poly plug budge or crack
paint. So, as I often want to admonish all the argumentative
graduate chemical and mechanical engineers out there shilling for
their epoxy stocks: Good engineering is a work done well enough,
cheap enough. All else is vanity.

Theory abounds.

Terry K