I was thinking if the planks were dry and shrunk then further drying wont
cause any splitting
The only pressure will be when the planks absorb water, now the planks are
under pressure anyway when wet, this is what seals the seams. I assume when
the boat was built, the inner plank edges were touching, the outer edges
were angled away so you can put in caulking.
I know a lot of you dont like the idea of planks pressuring each other but
is not this what happens anyway when they soak up water sealing the hull in
a conventional design?
People think something has to give if the edges are joined but are many
just making assumptions about this with no real experience.

"William R. Watt" wrote in message
...
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.




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"Scott Downey" wrote in message
...
I know a lot of you dont like the idea of planks pressuring each other but
is not this what happens anyway when they soak up water sealing the hull
in
a conventional design?

Yes. But in a conventional carvel hull, the caulking absorbs the extra
dimension of the expanding wood. When you glue is with epoxy, nothing is
left to absorm the expansion and the planks will eventually burst off the
ribs. The reason red cedar is used for stripplanking is because it is a soft
wood and therefore producing less pressure when it swells. Quite a few
builders, Paul Gartside is one of them, even state that layers of glass on a
larger stripplanked hull are not strong enough and they advise to cover the
strips with diagonal layer(s) of plywood first. I have also seen an oak hull
built this way; bead an cove strippplanked, covered by two layers of ply and
finished with for-and-aft running planks to add extra body and give it the
traditional look of carvel.

Meindert

Hi

"Meindert Sprang" skrev i en meddelelse
...
"Scott Downey" wrote in message
...

Yes. But in a conventional carvel hull, the caulking absorbs the extra
dimension of the expanding wood.

WHAT ?????

Don't anyone in this forum have any hands-on experience ?
Caulking is done at the outher third of the seam and the seam is prepared
for caulking, ------- It's bloddy _not_ the damned caulking that make the
hull watertight when you build a cravel planked boat, as the bloody seams
are TIGHT even before the caulking is there.
Do you realy think cravel build boats are just a bunch of planks with seems
inbetween that you look right thru , and that you just forget about the
craftmanship as you just Bang in caulking ???
Well that's _not_ how you build a cravel planked boat hull ------- and be
glad for that, as if this was how, no craftmanship or respect for the crafts
would survive the sailers counting on boatbuilders having the knowleage to
make a safe vessel.
Just becaurse you as amature builder, seen an old mistreated hull, with
inverts opened seams, do damn'ed not mean that this sort of bad
craftmanship, was what made these beautifull vessels ------ all it mean is,
that some ignorant Amature been doing a temp. repair, where a profesional
would have replaced the plank. ( nice case you trust your life upon ).

Bet you even think that caulking is just about banging in stuffing untill
the whole plank is forced to destroy the seams around and above, ------ seem
like you even mix two compleatly different technikes by talking about
caulking with Lapstrake building ; YOU DO NOT CAULK A LAPSTRAKE HULL, unless
it's old and worn , unless the planks shuld have been replaced decades ago,
don't you Amature boatbuilders know the difference between Lapstrake and
Cravel ; then how the hell can you avoid to crack the plank edge if you
start caulking a Lapstrake hull -------- don't you se it, don't you even
know that you can destroy a lapstrake hull by caulking it ????

P.C.

"P.C." wrote in message
k...
Hi

"Meindert Sprang" skrev i en meddelelse
...
"Scott Downey" wrote in message
...

Yes. But in a conventional carvel hull, the caulking absorbs the extra
dimension of the expanding wood.

WHAT ?????

It is my understanding that a carvel hull has a slight bevel on each plank,
so the planks only touch at the inside of the hull. The cotton used for
caulking is then driven about halfway in the seam, in order to form a sort
of watertight 'rope' slightly indenting the planksides.

Don't anyone in this forum have any hands-on experience ?
Caulking is done at the outher third of the seam and the seam is prepared
for caulking, ------- It's bloddy _not_ the damned caulking that make the
hull watertight when you build a cravel planked boat, as the bloody seams
are TIGHT even before the caulking is there.

Mmmm, I quote from the Boatbuilding Manual from Robert Steward:
"Carvel planking is usually made with the seams tight on the inside and open
on the outside to receive the cotton caulking, which makes the planking
watertight".

Bet you even think that caulking is just about banging in stuffing untill
the whole plank is forced to destroy the seams around and above, ------
seem
like you even mix two compleatly different technikes by talking about
caulking with Lapstrake building ; YOU DO NOT CAULK A LAPSTRAKE HULL,
unless
it's old and worn , unless the planks shuld have been replaced decades
ago,

Ehhrr, where exaclty was I referring to lapstake construction?

don't you Amature boatbuilders know the difference between Lapstrake and
Cravel ; then how the hell can you avoid to crack the plank edge if you
start caulking a Lapstrake hull -------- don't you se it, don't you even
know that you can destroy a lapstrake hull by caulking it ????

Well, at a boatbuilding school here in the Netherlands they build clinker
lapstrake hulls and they do put sikaflex between the strakes for caulking.
Nothing is destroyed by that.

Geez Per, why on earth ary you reacting so offensive????

Meindert

the boat was built, the inner plank edges were touching, the outer edges
were angled away so you can put in caulking.

Plank edges do not normally touch there is a gap that will allow for the
ultimate swelling or expansion of the plank. If the caulking cotton is
driven to tight (or you fill the seam with glue or epoxy) the plank will
'pull it's fastenings". The expanding plank has to go someplace.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions

wood is somewhat compressable so the thin edge will compress. however it
could also deform so when the wood dries out again the gap is larger.

it was common for boat hauled out over the winter to leak when first put
back in the water in the spring because the wood (and calking) had dried
out and opened over the winter. the boat would be left in shallow water to
soak up tight and stop leaking. it would them be bailed out and used for
the season.

there is an antique boat club near here which uses pumps in the spring to
keep the boats from sinking while they are soaking up.

"Steve" ) writes:
the boat was built, the inner plank edges were touching, the outer edges
were angled away so you can put in caulking.

Plank edges do not normally touch there is a gap that will allow for the
ultimate swelling or expansion of the plank. If the caulking cotton is
driven to tight (or you fill the seam with glue or epoxy) the plank will
'pull it's fastenings". The expanding plank has to go someplace.


--
My opinion and experience. FWIW

Steve
s/v Good Intentions




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