http://www.azom.com/details.asp?ArticleID=1116
Glued Carvel
Plank edges may be shaped and glued with a thickened epoxy mix or
alternatively the seams of dry fitted planks may be routed later to a
constant width and fitted with wooden splines which are glued into place.
This latter method is the usual treatment when a traditionally built carvel
craft is reconstructed using epoxy adhesives as part of a full restoration
program. Sometimes a thickened epoxy mix is introduced into the seams as an
alternative to wooden splines and this seems to be just as effective in
fastening the plank edges together. The planking is also glued to the spine
and framework, which on new boats is built of laminated hardwood, glued and
coated with epoxy.

If you glue the seams on a carvel planked hull, it is now longer a carvel
hull.. More like a stripped plank hull..

A carvel hull is built to allow the panks to expand and contract and for the
hull to twist with out opening a seam..

I have recaulked hulls that had been on the hard too long and the planking
was dry.. Being carefull not to drive the cotton too tight or it could cause
the plank to pull it's fastenings. Even if I only put in enough seam filler
to bring the seam flush with the planking surface, once the hull swelled the
excess filler would squeeze out 3/16" and would later have to be smoothed
down again.

If you want to glue the seams, select a strip planked design..


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

Hey Scott,

Are you planning on fairing away the seams? If so, then glued-carvel
would be fine ...not a lot different from strip-building, except for the
mention of a splined joint between the planks. If you are not going to
fair-away the seams, then it seems to me that the finish work will be
harder. With epoxy, you must really seal 100% of the wood, on all sides.
Epoxy's great stuff, but it also holds water at the epoxy/wood interface.
Hence the reason for a complete seal and then keeping it that way. I think
a fellow should either commit to a 100% seal on all sides, or forget epoxy
completely. My 2-bits. You might also check with Al Gunther, who frequents
r.b.b.. I can't remember for sure, but I think he's doing glued-carvel.
Or, I should say that he's building a 26' carvel-planked sailboat and when I
needed it, he had a lot of very good advice on the use of epoxy. Might try
a search on "Al's 26" and see what you find.

Brian


"Scott Downey" wrote in message
...

http://www.azom.com/details.asp?ArticleID=1116
Glued Carvel
Plank edges may be shaped and glued with a thickened epoxy mix or
alternatively the seams of dry fitted planks may be routed later to a
constant width and fitted with wooden splines which are glued into place.
This latter method is the usual treatment when a traditionally built
carvel
craft is reconstructed using epoxy adhesives as part of a full restoration
program. Sometimes a thickened epoxy mix is introduced into the seams as
an
alternative to wooden splines and this seems to be just as effective in
fastening the plank edges together. The planking is also glued to the
spine
and framework, which on new boats is built of laminated hardwood, glued
and
coated with epoxy.

Good method.
Ideally you should fiberglass the hull outside for extra protection.
While you are at it, fiberglass the inside too, it will increase strength
tremendously.
If you use biaxial glass, it will become a true sandwich.
Note that you don't really need to start with wood, you could us foam
strips, that would be even better.
Oops, we just got ourself a real nice composite boat . . .

--
Jacques
http://www.bateau.com

"Scott Downey" wrote in message
...

http://www.azom.com/details.asp?ArticleID=1116
Glued Carvel
Plank edges may be shaped and glued with a thickened epoxy mix or
alternatively the seams of dry fitted planks may be routed later to a
constant width and fitted with wooden splines which are glued into place.
This latter method is the usual treatment when a traditionally built
carvel
craft is reconstructed using epoxy adhesives as part of a full restoration
program. Sometimes a thickened epoxy mix is introduced into the seams as
an
alternative to wooden splines and this seems to be just as effective in
fastening the plank edges together. The planking is also glued to the
spine
and framework, which on new boats is built of laminated hardwood, glued
and
coated with epoxy.

Jacques says:

Oops, we just got ourself a real nice composite boat . . .

Sarcasm ill becomes you, Jacques....

;-)

However, if the planking cannot be fully encapsulated, meaning kept DRY, then
i'd hesitate to fill seams with something firm like splines or epoxy putty. If
the planking gets wet and tries to expand, something has to give. It might be
frames or fastenings.
Only if the planking is of a species that doesn't swell much, might you get away
with this.

Jacques Mertens wrote:

Good method.
Ideally you should fiberglass the hull outside for extra protection.
While you are at it, fiberglass the inside too, it will increase strength
tremendously.
If you use biaxial glass, it will become a true sandwich.
Note that you don't really need to start with wood, you could us foam
strips, that would be even better.
Oops, we just got ourself a real nice composite boat . . .

--
Jacques
http://www.bateau.com

"Scott Downey" wrote in message
...

http://www.azom.com/details.asp?ArticleID=1116
Glued Carvel
Plank edges may be shaped and glued with a thickened epoxy mix or
alternatively the seams of dry fitted planks may be routed later to a
constant width and fitted with wooden splines which are glued into place.
This latter method is the usual treatment when a traditionally built
carvel
craft is reconstructed using epoxy adhesives as part of a full restoration
program. Sometimes a thickened epoxy mix is introduced into the seams as
an
alternative to wooden splines and this seems to be just as effective in
fastening the plank edges together. The planking is also glued to the
spine
and framework, which on new boats is built of laminated hardwood, glued
and
coated with epoxy.

Correct: hybrid solutions could cause problems.
I share your doubts about glued seams. There are some epoxies that are
sufficiently flexible but why take a chance?
Either build her as wooden boat or as a composite (fiberglassed boat).

--
Jacques
http://www.bateau.com

"Jim Conlin" wrote in message
...
However, if the planking cannot be fully encapsulated, meaning kept DRY,
then
i'd hesitate to fill seams with something firm like splines or epoxy
putty. If
the planking gets wet and tries to expand, something has to give. It
might be
frames or fastenings.
Only if the planking is of a species that doesn't swell much, might you
get away
with this.

I heard that some Scandinavian builders built carvel boats with no gap
at all, just perfect seams, no glue, no caulking. Don't know details,
it's been a while since I looked into it. I believe they were sailing
vessels, 35' and more, they were built thus to provide more hull
stiffness, amoung other things, and they didn't seap/leak at all.

Sorry, can't recall how/where I found the info. But it means there's
more than one way to skin a cat...

Here's an interesting post I found while doing a quick search to see if
I could find any more info:
http://www.rtpnet.org/robroy/baidark.../Nov/0020.html

Search "no caulking" on this page:
http://www.mastmate.com/a-f.html

Another mention:
http://personal.riverusers.com/~emkay/building2.html

Well, I haven't found the references I wanted, but that's it for now.

Rufus


Jacques Mertens wrote:

Correct: hybrid solutions could cause problems.
I share your doubts about glued seams. There are some epoxies that are
sufficiently flexible but why take a chance?
Either build her as wooden boat or as a composite (fiberglassed boat).

--
Jacques
http://www.bateau.com

"Jim Conlin" wrote in message
...

However, if the planking cannot be fully encapsulated, meaning kept DRY,

then

i'd hesitate to fill seams with something firm like splines or epoxy

putty. If

the planking gets wet and tries to expand, something has to give. It

might be

frames or fastenings.
Only if the planking is of a species that doesn't swell much, might you

get away

with this.

Hi

"Rufus" skrev i en meddelelse
news:ehJHb.158921$8y1.474281@attbi_s52...
I heard that some Scandinavian builders built carvel boats with no gap
at all, just perfect seams, no glue, no caulking. Don't know details,
it's been a while since I looked into it. I believe they were sailing
vessels, 35' and more, they were built thus to provide more hull
stiffness, amoung other things, and they didn't seap/leak at all.
Snip

Sure you need no caulking if you don't want any, ------ this was common
knowleage and there are a number of tricks to make sure the seam work tight
without caulking ;
Hammer down a long rod along the plank edge and plane away untill you reach
the bottom of the grove made by deforming the plank edge. Then when soaked
the compressed wood will swell.
Place the planking forgetting about the seam ,as long as the seam is not
wider than a router bit, when you are sure the wood stabilised router away
along the seam and glue in a wood spline.
Still these old tricks work for true wooden boats ,Im'e not sure it's worth
the efford with any ply boat, even if a routered in wood spline along a
tortured seam is there from the start within the plans ,it's proberly a very
good idea but I wonder if any box boat plans ask this, ------ case so I
would like to se the naval architect recomend from his own hands-on
experience.

P.C.
http://www.designcommunity.com/scrap...mages/2985.jpg

Phil Bolger once started builing a hull that way but gave it up when he
found out how much the adhesive was costing, and finished it the old
fashioned way. You might want to cost out the project before getting started.

There are more flexible adhesives than epoxy. You might look into some of
them. I've heard of polyurethane being used on lapped strake (cliker) hulls.

Seams above the waterline tend to dry out and open up while seams below
the waterline swell up tight. If glued seams can't open as the wood dries
the wood may split. TF Jones encoutered this after 10 years on a lapped
strake canoe built light with thin strakes. That canoe was kept inside out
of the sun when not in use.

"Scott Downey" ) writes:
http://www.azom.com/details.asp?ArticleID=1116
Glued Carvel
Plank edges may be shaped and glued with a thickened epoxy mix or
alternatively the seams of dry fitted planks may be routed later to a
constant width and fitted with wooden splines which are glued into place.
This latter method is the usual treatment when a traditionally built carvel
craft is reconstructed using epoxy adhesives as part of a full restoration
program. Sometimes a thickened epoxy mix is introduced into the seams as an
alternative to wooden splines and this seems to be just as effective in
fastening the plank edges together. The planking is also glued to the spine
and framework, which on new boats is built of laminated hardwood, glued and
coated with epoxy.




--
------------------------------------------------------------------------------
William R Watt National Capital FreeNet Ottawa's free community network
homepage: www.ncf.ca/~ag384/top.htm
warning: non-freenet email must have "notspam" in subject or it's returned