Deck core delamination

Posted by davisjonathan1946 (jon@…>)

Does anyone have any experience of repairing a deck which is suffering
from delamination of the core.Do members think that the underside of
the deck head should be cut away where the delamination is and then a
new balsa core glued with a resin putty mix to the outer skin with a
new inner lay up of cloth and resin or could it be possible to pump
resin into the areas through holes in the outer skin forming a new
bond ,would appreciate members thoughts and advice

Posted by Frank Minelli (myslo@…>)
The deck is balsa-cored?? I tought decks to be plywood-cored.
I have no experience with deck cores being wet, but do with the hull core, which is, if course, balsa. We removed the outer hull, to one ft. above the water line, removed the balsa, laid in new balsa and soaked that in very thin expoxy with a 72 hr curing time. Then we simply laid up a new outer hull, of course, also in epoxy.
First step, seems to me, is to get an accurate ¨chart¨ of all the wet spots. Problem, seems to me, is to replace plywood only partially, and bond it to the remaining plywood in such a way as to give the over all area its original strenght back.

I would be interest to learn what model and year Freedom this is, and to what this leakage has been attributed.davisjonathan1946 <jon@…> wrote:
Does anyone have any experience of repairing a deck which is suffering from delamination of the core.Do members think that the underside of the deck head should be cut away where the delamination is and then a new balsa core glued with a resin putty mix to the outer skin with a new inner lay up of cloth and resin or could it be possible to pump resin into the areas through holes in the outer skin forming a new bond ,would appreciate members thoughts and advice
Yahoo! for Good Click here to donate to the Hurricane Katrina relief effort.

Posted by lance_ryley (lance_ryley@…>)

Jon,
If the core is delaminated but not wet, there’s a cool technique you
can do, depending on how large the delaminated areas are. It takes two
people.

  1. Buy a bunch of #10 flathead screws.
  2. Using a 9/64" drill bit, drill holes through the top laminate at a
    spacing of about 3".

Now mix up your epoxy, and use a syringe.
3. Start at the middle and inject epoxy into a hole. when it starts
coming out an adjacent hole, put in a screw (paraffin wax will help
get it out later). Stay at that hole and inject again until the resin
comes out another hole, plug the same way. when it starts to back
pressure, pull out the syringe and plug that hole.
4. Move to the next open hole and repeat to fill that void.
5. wipe up any spillage and wait til the epoxy gets rubbery, then take
out the screws and fair the tops of the holes with thickened epoxy.

Just be sure not to inject too much epoxy or you could distort the
deck shape.

(picked out of BoatWorks)

Lance

— In freedomyachts2003@yahoogroups.com, “davisjonathan1946”
<jon@j…> wrote:

Does anyone have any experience of repairing a deck which is
suffering
from delamination of the core.Do members think that the underside of
the deck head should be cut away where the delamination is and then
a
new balsa core glued with a resin putty mix to the outer skin with a
new inner lay up of cloth and resin or could it be possible to pump
resin into the areas through holes in the outer skin forming a new
bond ,would appreciate members thoughts and advice

Posted by macks011 (macks04@…>)

Deck core is repairable from the underside and is an option if you
have good access to the area. The advantage is that you don’t have
to
deal with the cosmetic issues. The disadvantage is that you are
working overhead and gravity is a bitch. This past winter, I
repaired
8 sq. ft of rotted core in my cabin top. It is a messy, complicated
job. But, once you are comfortable with the technique, the job moves
along. I carefully removed the bottom skin in large sections, sanded
off the balsa residue and saved them for reuse. Then the damaged
balsa
core was scraped out and the deck skin was prepped for epoxy. Using
West System epoxy and Baltek Contourcore, I laid in the core and
supported it from underneath with press clamps and pvc tubing.

After that set up, I reused the bottom skins and epoxied them to the
Baltec core. The final step was to glass the seams in the bottom
skin.

It was recommended that I use the vacuum bagging process and had the
area been larger, I probably would have tried it, but I don’t have
experience with it and didn’t want to learn on the job.


— In freedomyachts2003@yahoogroups.com, “davisjonathan1946”
<jon@j…> wrote:

Does anyone have any experience of repairing a deck which is
suffering
from delamination of the core.Do members think that the underside
of
the deck head should be cut away where the delamination is and
then
a
new balsa core glued with a resin putty mix to the outer skin with
a
new inner lay up of cloth and resin or could it be possible to
pump
resin into the areas through holes in the outer skin forming a new
bond ,would appreciate members thoughts and advice

Posted by Alan Kusinitz (akusinitz@…>)

My F-33 as most (all?) freedoms has balsa cored decks. The placement of the lifeline stanchions is a bit too far inboard (I have the teak toerail not the aluminum toerail) and one or two of the botls at the base go through the cored part fo the deck. I have so far found one spot with wet balsa at a stanchion and one at the bow pulpti. I ground/cut out the inner skin for a few inches filled with thickened epoxy and an aluminum backing plate to make it stronger then before. Gradually I’ve been removing hardware from the cabin top etc. and routing out the balsa with a dremel tool and filling with epoxy and redrilling and bedding and remounting as a protective measure.
The prior owner found leakage and wet balsa in a larger area to starboard of the companionway in the cabin top. He cut away the inner skin, put in balsa and fiberglassed over it. He did a very good job.
I’m not sure deck delamination is said to mean overall separation of the two skins and balsa. Generally its just localized issues of wet portions of the balsa. If the latter I would work from the inside and use epoxy putty for small areas and balsa and glass for large areas. Most are under the headliner or in lockers so cosmetics isn’t really an issue. I’m not sure of the cabin sides and if port leaks go into balsa or not.
Alan F-33 Hull #51 SEAPR 1982

----- Original Message -----
From: Frank Minelli
To: freedomyachts2003@yahoogroups.com
Sent: Wednesday, September 21, 2005 7:34 PM
Subject: Re: [freedomyachts2003] Deck core delamination

The deck is balsa-cored?? I tought decks to be plywood-cored.
I have no experience with deck cores being wet, but do with the hull core, which is, if course, balsa. We removed the outer hull, to one ft. above the water line, removed the balsa, laid in new balsa and soaked that in very thin expoxy with a 72 hr curing time. Then we simply laid up a new outer hull, of course, also in epoxy.
First step, seems to me, is to get an accurate ¨chart¨ of all the wet spots. Problem, seems to me, is to replace plywood only partially, and bond it to the remaining plywood in such a way as to give the over all area its original strenght back.

I would be interest to learn what model and year Freedom this is, and to what this leakage has been attributed.davisjonathan1946 <jon@…> wrote:
Does anyone have any experience of repairing a deck which is suffering from delamination of the core.Do members think that the underside of the deck head should be cut away where the delamination is and then a new balsa core glued with a resin putty mix to the outer skin with a new inner lay up of cloth and resin or could it be possible to pump resin into the areas through holes in the outer skin forming a new bond ,would appreciate members thoughts and advice


Yahoo! for GoodClick here to donate to the Hurricane Katrina relief effort.

Posted by isleblues (milo.militello@…>)

Just my two cents . . .
J/24 owners are very experinced with moist balsa core and what to do
about it.
The drill holes in the deck layer, take a 90 degree bent nail and put
it in a drill as a bit, and place the nail between the laminates and
let the nail spin under the deck, removing the moist balsa. Then they
pump epoxy into the newly created void surrounding the drill hole -
they drill holes all around the delaminated or moist sections of the
deck until they hit dry balsa.

just an FYI.
Milo
F32 island blues

Posted by Michel Capel (mike_c_f35ck@…>)

Connecting new pieces of core to remaining pieces is not necessary.
The strength of a cored laminate is created by the distance between
the outer and the inner layers of laminate. The core is just a way
to keep the two laminated at distance of each other. Think of box-
section metal tubing or ladder frame bridge sides. I think replacing
a wet cored deck can only be done from the top; gravity is needed to
fill all the voids. It’s certainly doable, but I would not use
balsa but closed cell foam as a replacement for the balsa. As said,
you first need to map out the wetted areas. A first impression you
can get by sounding with a mallet. Next, drill small holes in and
around the suspected areas. The core material that comes out with
the drill shows whether it’s wet or dry. Then use a short sabblade
to remove the top layer of laminate.
gr
Michel



— In freedomyachts2003@yahoogroups.com, Frank Minelli <myslo@y…>
wrote:

The deck is balsa-cored?? I tought decks to be plywood-cored.
I have no experience with deck cores being wet, but do with the
hull core, which is, if course, balsa. We removed the outer hull,
to one ft. above the water line, removed the balsa, laid in new
balsa and soaked that in very thin expoxy with a 72 hr curing time.
Then we simply laid up a new outer hull, of course, also in epoxy.
First step, seems to me, is to get an accurate ¨chart¨ of all
the wet spots. Problem, seems to me, is to replace plywood only
partially, and bond it to the remaining plywood in such a way as to
give the over all area its original strenght back.

I would be interest to learn what model and year Freedom this is,
and to what this leakage has been attributed.

davisjonathan1946 <jon@j…> wrote:
Does anyone have any experience of repairing a deck which is
suffering
from delamination of the core.Do members think that the underside
of
the deck head should be cut away where the delamination is and
then a
new balsa core glued with a resin putty mix to the outer skin with
a
new inner lay up of cloth and resin or could it be possible to
pump
resin into the areas through holes in the outer skin forming a new
bond ,would appreciate members thoughts and advice

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Posted by andre laviolette (andrelaviolette@…>)
CAUTION !

If you are to use foam instead of balsa in deck repair, be sure that the foam you are to use does not soften in the heat of the sun. Foam used in hulls is not necessarily the same as used in deck construction. This info is obtainable from manufacturer.

Andre , " Scaramanga "
Michel Capel <mike_c_f35ck@…> wrote:
Connecting new pieces of core to remaining pieces is not necessary. The strength of a cored laminate is created by the distance between the outer and the inner layers of laminate. The core is just a way to keep the two laminated at distance of each other. Think of box-section metal tubing or ladder frame bridge sides. I think replacing a wet cored deck can only be done from the top; gravity is needed to fill all the voids. It’s certainly doable, but I would not use balsa but closed cell foam as a replacement for the balsa. As said, you first need to map out the wetted areas. A first impression you can get by sounding with a mallet. Next, drill small holes in and around the suspected areas. The core material that comes out with the drill shows whether it’s wet or dry. Then use a short sabblade to remove the top layer
of laminate.grMichel— In freedomyachts2003@yahoogroups.com, Frank Minelli <myslo@y…> wrote:> The deck is balsa-cored?? I tought decks to be plywood-cored.> I have no experience with deck cores being wet, but do with the hull core, which is, if course, balsa. We removed the outer hull, to one ft. above the water line, removed the balsa, laid in new balsa and soaked that in very thin expoxy with a 72 hr curing time. Then we simply laid up a new outer hull, of course, also in epoxy.> First step, seems to me, is to get an accurate ¨chart¨ of all the wet spots. Problem, seems to me, is to replace plywood only partially, and bond it to the remaining plywood in such a way as to give the over all area its original strenght back.> > I would be interest to learn what model and year Freedom
this is, and to what this leakage has been attributed.> > davisjonathan1946 <jon@j…> wrote:> Does anyone have any experience of repairing a deck which is suffering > from delamination of the core.Do members think that the underside of > the deck head should be cut away where the delamination is and then a > new balsa core glued with a resin putty mix to the outer skin with a > new inner lay up of cloth and resin or could it be possible to pump > resin into the areas through holes in the outer skin forming a new > bond ,would appreciate members thoughts and advice> > > > > SPONSORED LINKS > Sailing schools Sailing instruction Sailing lesson Sailing course Sailing adventure Sailing > > ---------------------------------> YAHOO! GROUPS LINKS > > > Visit your group
“freedomyachts2003” on the web.> > To unsubscribe from this group, send an email to:> freedomyachts2003-unsubscribe@yahoogroups.com> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > ---------------------------------> > > > > > > ---------------------------------> Yahoo! for Good> Click here to donate to the Hurricane Katrina relief effort.__________________________________________________Do You Yahoo!?Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

Posted by Alan Kusinitz (akusinitz@…>)

My understanding is that in places with hardware the compression strength is also important and that’s where balsa or other hard filler is needed.
Alan

----- Original Message -----
From: Michel Capel
To: freedomyachts2003@yahoogroups.com
Sent: Sunday, September 25, 2005 10:20 AM
Subject: [freedomyachts2003] Re: Deck core delamination
Connecting new pieces of core to remaining pieces is not necessary. The strength of a cored laminate is created by the distance between the outer and the inner layers of laminate. The core is just a way to keep the two laminated at distance of each other. Think of box-section metal tubing or ladder frame bridge sides. I think replacing a wet cored deck can only be done from the top; gravity is needed to fill all the voids. It’s certainly doable, but I would not use balsa but closed cell foam as a replacement for the balsa. As said, you first need to map out the wetted areas. A first impression you can get by sounding with a mallet. Next, drill small holes in and around the suspected areas. The core material that comes out with the drill shows whether it’s wet or dry. Then use a short sabblade to remove the top layer of laminate.grMichel— In freedomyachts2003@yahoogroups.com, Frank Minelli <myslo@y…> wrote:> The deck is balsa-cored?? I tought decks to be plywood-cored.> I have no experience with deck cores being wet, but do with the hull core, which is, if course, balsa. We removed the outer hull, to one ft. above the water line, removed the balsa, laid in new balsa and soaked that in very thin expoxy with a 72 hr curing time. Then we simply laid up a new outer hull, of course, also in epoxy.> First step, seems to me, is to get an accurate ¨chart¨ of all the wet spots. Problem, seems to me, is to replace plywood only partially, and bond it to the remaining plywood in such a way as to give the over all area its original strenght back.> > I would be interest to learn what model and year Freedom this is, and to what this leakage has been attributed.> > davisjonathan1946 <jon@j…> wrote:> Does anyone have any experience of repairing a deck which is suffering > from delamination of the core.Do members think that the underside of > the deck head should be cut away where the delamination is and then a > new balsa core glued with a resin putty mix to the outer skin with a > new inner lay up of cloth and resin or could it be possible to pump > resin into the areas through holes in the outer skin forming a new > bond ,would appreciate members thoughts and advice> > > > > SPONSORED LINKS > Sailing schools Sailing instruction Sailing lesson Sailing course Sailing adventure Sailing > > ---------------------------------> YAHOO! GROUPS LINKS > > > Visit your group “freedomyachts2003” on the web.> > To unsubscribe from this group, send an email to:> freedomyachts2003-unsubscribe@yahoogroups.com> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > ---------------------------------> > > > > > > ---------------------------------> Yahoo! for Good> Click here to donate to the Hurricane Katrina relief effort.

Posted by Michel Capel (mike_c_f35ck@…>)

True, but I think balsa is not hard enough for that. Plywood
inserts or solid epoxy (filler) will probably be better.

— In freedomyachts2003@yahoogroups.com, “Alan Kusinitz”
<akusinitz@y…> wrote:

My understanding is that in places with hardware the compression
strength is also important and that’s where balsa or other hard
filler is needed.
Alan
----- Original Message -----
From: Michel Capel
To: freedomyachts2003@yahoogroups.com
Sent: Sunday, September 25, 2005 10:20 AM
Subject: [freedomyachts2003] Re: Deck core delamination

Connecting new pieces of core to remaining pieces is not
necessary.
The strength of a cored laminate is created by the distance
between
the outer and the inner layers of laminate. The core is just a
way
to keep the two laminated at distance of each other. Think of
box-
section metal tubing or ladder frame bridge sides. I think
replacing
a wet cored deck can only be done from the top; gravity is
needed to
fill all the voids. It’s certainly doable, but I would not use
balsa but closed cell foam as a replacement for the balsa. As
said,
you first need to map out the wetted areas. A first impression
you
can get by sounding with a mallet. Next, drill small holes in
and
around the suspected areas. The core material that comes out
with
the drill shows whether it’s wet or dry. Then use a short
sabblade
to remove the top layer of laminate.
gr
Michel

— In freedomyachts2003@yahoogroups.com, Frank Minelli
<myslo@y…>
wrote:

The deck is balsa-cored?? I tought decks to be plywood-cored.
I have no experience with deck cores being wet, but do with
the
hull core, which is, if course, balsa. We removed the outer
hull,
to one ft. above the water line, removed the balsa, laid in
new
balsa and soaked that in very thin expoxy with a 72 hr curing
time.
Then we simply laid up a new outer hull, of course, also in
epoxy.
First step, seems to me, is to get an accurate ¨chart¨ of
all
the wet spots. Problem, seems to me, is to replace plywood
only
partially, and bond it to the remaining plywood in such a way
as to
give the over all area its original strenght back.

I would be interest to learn what model and year Freedom this
is,
and to what this leakage has been attributed.

davisjonathan1946 <jon@j…> wrote:
Does anyone have any experience of repairing a deck which is
suffering
from delamination of the core.Do members think that the
underside
of
the deck head should be cut away where the delamination is and
then a
new balsa core glued with a resin putty mix to the outer skin
with
a
new inner lay up of cloth and resin or could it be possible to
pump
resin into the areas through holes in the outer skin forming a
new
bond ,would appreciate members thoughts and advice

SPONSORED LINKS
Sailing schools Sailing instruction Sailing lesson Sailing
course
Sailing adventure Sailing


YAHOO! GROUPS LINKS

Visit your group "freedomyachts2003" on the web.

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of

Service.



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Click here to donate to the Hurricane Katrina relief effort.

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lesson
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Posted by Jerome Weinraub (zayde@…>)

Balsa is not hard core. Balsa replacement with epoxy and /or plywood is.

----- Original Message -----
From: Alan Kusinitz
To: freedomyachts2003@yahoogroups.com
Sent: Sunday, September 25, 2005 10:49 AM
Subject: Re: [freedomyachts2003] Re: Deck core delamination

My understanding is that in places with hardware the compression strength is also important and that’s where balsa or other hard filler is needed.
Alan

----- Original Message -----
From: Michel Capel
To: freedomyachts2003@yahoogroups.com
Sent: Sunday, September 25, 2005 10:20 AM
Subject: [freedomyachts2003] Re: Deck core delamination
Connecting new pieces of core to remaining pieces is not necessary. The strength of a cored laminate is created by the distance between the outer and the inner layers of laminate. The core is just a way to keep the two laminated at distance of each other. Think of box-section metal tubing or ladder frame bridge sides. I think replacing a wet cored deck can only be done from the top; gravity is needed to fill all the voids. It’s certainly doable, but I would not use balsa but closed cell foam as a replacement for the balsa. As said, you first need to map out the wetted areas. A first impression you can get by sounding with a mallet. Next, drill small holes in and around the suspected areas. The core material that comes out with the drill shows whether it’s wet or dry. Then use a short sabblade to remove the top layer of laminate.grMichel— In freedomyachts2003@yahoogroups.com, Frank Minelli <myslo@y…> wrote:> The deck is balsa-cored?? I tought decks to be plywood-cored.> I have no experience with deck cores being wet, but do with the hull core, which is, if course, balsa. We removed the outer hull, to one ft. above the water line, removed the balsa, laid in new balsa and soaked that in very thin expoxy with a 72 hr curing time. Then we simply laid up a new outer hull, of course, also in epoxy.> First step, seems to me, is to get an accurate ¨chart¨ of all the wet spots. Problem, seems to me, is to replace plywood only partially, and bond it to the remaining plywood in such a way as to give the over all area its original strenght back.> > I would be interest to learn what model and year Freedom this is, and to what this leakage has been attributed.> > davisjonathan1946 <jon@j…> wrote:> Does anyone have any experience of repairing a deck which is suffering > from delamination of the core.Do members think that the underside of > the deck head should be cut away where the delamination is and then a > new balsa core glued with a resin putty mix to the outer skin with a > new inner lay up of cloth and resin or could it be possible to pump > resin into the areas through holes in the outer skin forming a new > bond ,would appreciate members thoughts and advice> > > > > SPONSORED LINKS > Sailing schools Sailing instruction Sailing lesson Sailing course Sailing adventure Sailing > > ---------------------------------> YAHOO! GROUPS LINKS > > > Visit your group “freedomyachts2003” on the web.> > To unsubscribe from this group, send an email to:> freedomyachts2003-unsubscribe@yahoogroups.com> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > ---------------------------------> > > > > > > ---------------------------------> Yahoo! for Good> Click here to donate to the Hurricane Katrina relief effort.