splining carvel hulls
Doc
Leo Edwardsson wrote in message ...
>Hi all,
>
>does anybody have any actual experience of splining carvel planked hulls
>(i.e. epoxy bonding thin strips of wood into the gaps between planks,
>sealing them permanently) in order to do away with caulking? A friend of
>mine is currently doing this to his 60 year yacht, having first allowed
>the planking to dry out as much as possible. The idea apparently is to
>turn the hull into a 'semi-monocoque' structure.
Okay, a couple of thoughts on this. First, a carvel hull is just about
infinitely rebuildable. That is, the planks are easily removable. Gooing
them together means that any planks removed will result in considerable
damage to adjoining planks.
I have _seen_ a couple of these splined boats. They _look_ okay, but I
don't know about long term . This boat has lasted sixty years as is. Why
screw around with what works?
>
>To me, this seems like a very questionable procedure. Once the boat is
>back in the water and the planks re-absorb moisture and expand, I'd have
>thought shearing stresses on the rovings and frames would be certain to
>cause major damage. If I were doing this, I'd go ahead and epoxy-glass the
>whole hull below the waterline. Done right, you KNOW that's going to work.
Okay, you have come up with another set of reasons not to spline it.
As for the epoxy and glass:done at all it's questionable, for exactly the
same reasons as above. Wood expands, shears away from the epoxy-glass. Bad
move. Just fix it, conventionally.
>
>Even though it's not my boat, I hate the thought of it busting itself
>apart. It would set my mind at ease if anybody who has successfully done
>this could tell me how it works.
I have heard of this being done successfully (that is, the boat has lasted
over ten years) on a few new boats, built splined from the beginning. As
systems go, I don't think it's very good, for the reasons stated above.
>On the other hand, if there's a chorus of
>"No, no, for God's sake don't do it" replies from shipwrights around the
>world, maybe I can talk him into glass sheathing the bottom so he never
>has to worry about hull moisture content again.
Talk him into learning how to caulk a boat properly. Glassing a carvel hull
is an absolute last resort, to be used ONLY if the alternative is
chainsawing the boat into fireplace lengths. Period.
>
J.F. Milliken, Boatbuilder
Cape Cod
Doc
mor...@usaor.net wrote in message ...
>On Sat, 3 Oct 1998 13:36:22, "Doc" <jfm...@capecod.net> wrote:
>
>> Talk him into learning how to caulk a boat properly. Glassing a carvel
hull
>> is an absolute last resort, to be used ONLY if the alternative is
>> chainsawing the boat into fireplace lengths. Period.
>
>add much value, strength, and many years to the life of a boat. You
>don't have to wait until the hull is in poor condition.
>
Okay, one by one-
'done right': Inside and out, with bone dry wood, no grease or oils in the
wood, all the way from keel to sheer. The pure work involved is at least as
much as a conventional rebuild. Consider that all bulkheads, machinery and
such have to be removed, all paint and such too. Inside and out.
'add value'. Nope. Not unless the potential buyer is another of those
mesmerised by fiberglass, in which case they should buy plain fiberglass. A
wise boat buyer, or a wise surveyor, will steer well clear of such a horror.
'add.....strength'. Nope again. What I have seen happen was rot. Any
preexisting problems are encapsulated in glass and resin. In only one case
was any strength added: the boat was essentially rotten and ready to fall
apart. A half inch or more of fiberglass matt was added to the entire hull.
Freeboard was lowered to a dangerous point. And for the time, effort and
expense, a better boat could have been bought.
'add.....years to the life' No way, Jose. Any dampness in the wood, either
from inside or out, is trapped. And there will be moisture. Rot happens.
Period. What is worse, it is invisible until it has spread beyond economical
repair. Any other problems, ditto. I have seen several perfectly good boats
fiberglassed and chainsawed a few years later. A very few years later. These
boats could be still afloat today if they had been maintained properly.
As I said before, learn to caulk. Learn simple repairs.A (conventioanlly
caulked) carvel planked boat is a well proven system. Parts can be removed
and repaired with relative ease, a few tools and some skills. Fiberglassing
a sound wooden carvel boat is just plain crazy.
If you must sheathe the bottom with something, try copper.
Leo Edwardsson
does anybody have any actual experience of splining carvel planked hulls
(i.e. epoxy bonding thin strips of wood into the gaps between planks,
sealing them permanently) in order to do away with caulking? A friend of
mine is currently doing this to his 60 year yacht, having first allowed
the planking to dry out as much as possible. The idea apparently is to
turn the hull into a 'semi-monocoque' structure.
To me, this seems like a very questionable procedure. Once the boat is
back in the water and the planks re-absorb moisture and expand, I'd have
thought shearing stresses on the rovings and frames would be certain to
cause major damage. If I were doing this, I'd go ahead and epoxy-glass the
whole hull below the waterline. Done right, you KNOW that's going to work.
Even though it's not my boat, I hate the thought of it busting itself
apart. It would set my mind at ease if anybody who has successfully done
this could tell me how it works. On the other hand, if there's a chorus of
"No, no, for God's sake don't do it" replies from shipwrights around the
world, maybe I can talk him into glass sheathing the bottom so he never
has to worry about hull moisture content again.
Leo Edwardsson
macnaughton.com
needed if there's nothing else wrong with the boat. There is much more labor
in splining the seams than in decades of caulking maintenance. Further the
swelling problem can be pretty bad. You could tear the whole boat apart.
Some boats are built this way originally and if designed for it and built by
a builder carefully selecting the stock for minimum expansion and
contraction with changes in moisture content of the wood they can be
successful. I would never try to convert a boat from caulked seam to glued
seam without totally replanking it. The idea that there's a lot of
maintenance to caulking is essentially a myth unless there's something else
wrong with the boat like broken frames or broken fastenings.
Tom MacNaughton
Naval Architect
http://www.macnaughtongroup.com
Doc wrote in message ...
>
>Leo Edwardsson wrote in message ...
>>Hi all,
>>
>>does anybody have any actual experience of splining carvel planked hulls
>>(i.e. epoxy bonding thin strips of wood into the gaps between planks,
>>sealing them permanently) in order to do away with caulking? A friend of
>>mine is currently doing this to his 60 year yacht, having first allowed
>>the planking to dry out as much as possible. The idea apparently is to
>>turn the hull into a 'semi-monocoque' structure.
>
>Okay, a couple of thoughts on this. First, a carvel hull is just about
>infinitely rebuildable. That is, the planks are easily removable. Gooing
>them together means that any planks removed will result in considerable
>damage to adjoining planks.
>
>I have _seen_ a couple of these splined boats. They _look_ okay, but I
>don't know about long term . This boat has lasted sixty years as is. Why
>screw around with what works?
>>
>>To me, this seems like a very questionable procedure. Once the boat is
>>back in the water and the planks re-absorb moisture and expand, I'd have
>>thought shearing stresses on the rovings and frames would be certain to
>>cause major damage. If I were doing this, I'd go ahead and epoxy-glass the
>>whole hull below the waterline. Done right, you KNOW that's going to work.
>
>Okay, you have come up with another set of reasons not to spline it.
>
>As for the epoxy and glass:done at all it's questionable, for exactly the
>same reasons as above. Wood expands, shears away from the epoxy-glass. Bad
>move. Just fix it, conventionally.
>>
>>Even though it's not my boat, I hate the thought of it busting itself
>>apart. It would set my mind at ease if anybody who has successfully done
>>this could tell me how it works.
>
>I have heard of this being done successfully (that is, the boat has lasted
>over ten years) on a few new boats, built splined from the beginning. As
>systems go, I don't think it's very good, for the reasons stated above.
>
>>On the other hand, if there's a chorus of
>>"No, no, for God's sake don't do it" replies from shipwrights around the
>>world, maybe I can talk him into glass sheathing the bottom so he never
>>has to worry about hull moisture content again.
>
>Talk him into learning how to caulk a boat properly. Glassing a carvel hull
>is an absolute last resort, to be used ONLY if the alternative is
>chainsawing the boat into fireplace lengths. Period.
>>
Leo Voorneveld
I splined a couple of boats,from a dayboat to seagoing yachts.
Over the years wood shrink aspecial above the waterline,the outer cells will
expand again but the corecells of thick planked vessels less.
Another reason planking can get "gapping" is that the frames are
at a 90 degree angle to the skinplanking,this will create different
shrinking behaviours.
So it is possible to spline with a good reason.
The question only when ?
Is a ratio of 20:1 it -the planking is 10 cm wide and the gap 0.5 cm,will
the planking expand enough,certainly you will need a lot of caulking.A
discussion maybe-gap filling ratio ?
The problem with splining is as mentioned that it will (when wet)
will create to much force.
The answer is to use a softwood as splining like fir.This will certainly
compress under the loads applied.
Difficulty is that you have to take care with sanding.
Another aspect is which glue you use,
-waterproof
-capable of flexibility
-gap filling
-strong
-long lasting
The second demand outrules epoxy.
Here (Netherlands) you can use resorcinol formaldehyde-it is two component
stuff-is it known in the USA ,UK,NZ,Australia as well ??
The last demand outrules polyurethane based glues
It will tend to harden over the years,becoming brittle.
Still better then epoxy for this kind of work.
This all can never replace good craftsmanship ,this will mostly be the
paramount factor to good results.
Better a good job in epoxy then a lousy job in the best way.
By the way it aint good to sheathen only the waterplane in glass
with epoxy or polyester.There is something called capillary suction.
Water will get between wood and the sheating and start to rot rapidly.
The trick with epoxy is that for conservation you have to shield the whole
piece,in and outside the boat,outside with a layer off glass to
make it stronger inside with glass (superstrong) or with very thin epoxy and
saturate a few mm deep into the wood.
I would like to have more info about the glues used over the world,
I want to work outside Europe thats why.
greetings leo
Doc
Leo Edwardsson wrote in message ...
>
>thanks for your input. I should have said in the original post that my
>friend has already routed out the gaps between the planks below the
>waterline and started gluing in the splines, so going back to caulking is
>not on the cards. Unfortunately, your knowledgable advice has pretty much
>confirmed my own fears about the procedure.
As Tom has suggested, narrow up the splines and put a caulking bevel on 'em.
>
>When I suggested glassing the bottom, I was thinking of it as a way to
>stabilize the moisture content of the planks. If you sheathed the bottom
>AND sealed the inside of the hull with epoxy, would you not then prevent
>the planking from absorbing moisture? This is what I meant by 'doing it
>right', and I once read that it works.
I fear you may have read it in a Wildly Expensive Shoddy Technique (WEST)
brochure. In theory, _maybe_, in practice it never gets completely sealed.
And once a little moisture gets in, it's toast. Rot, delams and all.
>But having no experience in the
>field, naturally I defer to my elders and betters.
As William F. Halsey once said " I'm not that damned old".
>
J. F. Milliken, Boatbuilder
Cape Cod
Peter Keller
the reasons mentioned in previous posts. I was just wondering why no-one
had brought up the subject of economics? I'm not up on the prices of
things, but surely, if I had a choice between sheathing a boat in gallons of
$$$epoxy or pounding in a bit of cotton, disregarding (stupidly) the
long-term effects, I know what I'd choose.
--
Peter Keller
Boatbuilder
p...@conan.ids.net
"My object in living is to unite my avocation with my vocation
As my two eyes make one in sight.
Only where love and need are one, and the work is play for mortal stakes,
Is the deed ever really done for Heaven and future's sakes."
-Robert Frost
Leo Edwardsson
thanks for your input. I should have said in the original post that my
friend has already routed out the gaps between the planks below the
waterline and started gluing in the splines, so going back to caulking is
not on the cards. Unfortunately, your knowledgable advice has pretty much
confirmed my own fears about the procedure.
When I suggested glassing the bottom, I was thinking of it as a way to
stabilize the moisture content of the planks. If you sheathed the bottom
AND sealed the inside of the hull with epoxy, would you not then prevent
the planking from absorbing moisture? This is what I meant by 'doing it
right', and I once read that it works. But having no experience in the
field, naturally I defer to my elders and betters.
So, given that there's no going back (planking is Huon Pine, a legendary
boat-building timber here in Tasmania and hence now scarce as hen's
teeth), what would you guys suggest?
Leo Edwardsson
macnaughton.com
seen it another way. How long does it take to say. Roll a strand on your
knee to make it a little more compact and roll it in a ball to hold in your
hand? Then you're right into using the irons and mallet with the cotton and
that is just a visual thing. I'm not saying some people wouldn't take longer
than 15 minutes but I don't think I've ever taken over a half hour with
anyone who had any manual skills at all.
Come to think of it the first caulking I did was on an old dinghy. I was
roughly putting a plank on it and my father said "you need to caulk that". I
just did it. I suppose I might have been 8 or 10. I suppose I did a lousy
job. I remember asking my father whether I'd done it right and he said
"you'll find out". I said "what if I didn't?". He said, "then you'll have to
do it again". That was my sole instruction in caulking.
Tom MacNaughton
Naval Architect
http://www.macnaughtongroup.com
Dave Fleming wrote in message <361c9b5f...@news.pipeline.com>...
>I dunno Tom, taught people to caulk in 15 minutes?
>Where were you when I was an apprentice?
>15 minutes and maybe someone will have started to 'hank' the cotton or
>set up to spin the oakum.
>Think maybe you need to clarify that statement?
>dave
>
macnaughton.com
to glass it. If it isn't in good shape you better get it in good shape
before you glass it anyway.
Also glassing reduces value on a conventional carvel planked boat
substantially in that potential buyers of wooden boats will want to remove
the glass and will be extremely suspicious of why the glass was put on. It
is usually done by people who do not know how to repair or maintain their
boat.
For those who think this means I'm down on fiberglass we are great promotors
of building sheathed strip boats. But that is a case where the boat was
designed for glass sheathing inside and out.
Tom MacNaughton
Naval Architect
http://www.macnaughtongroup.com
mor...@usaor.net wrote in message ...
>On Sat, 3 Oct 1998 13:36:22, "Doc" <jfm...@capecod.net> wrote:
>
>> Talk him into learning how to caulk a boat properly. Glassing a carvel
hull
>> is an absolute last resort, to be used ONLY if the alternative is
>> chainsawing the boat into fireplace lengths. Period.
>
>I disagree. Glassing a carvel hull, providing the job is done right, can
>add much value, strength, and many years to the life of a boat. You
>don't have to wait until the hull is in poor condition.
>
>Regards,
>Morgan
macnaughton.com
structure! We fix frames and planking and have a boat with some value and
strength. However there is another point here. We get boats brought to us
all the time that the owner's want to fiberglass because they are "old and
leaking too badly". So far it has proved more economical to repair them than
to fiberglass them in every case.
In one case a 36' powerboat was bought to us that had two pumps running
continuously. The owner said he wanted it glassed. We talked him into
letting us check it out. Basically the boat needed two things. First, about
8 screws replaced in each garboard near the horn timber where the originals
had been much shorter than normal. Second about 15 feet total of crumbled
seam stopping removed, the underlying cotton just reset, not removed, and
new stopping put in.
Tom MacNaughton
Naval Architect
http://www.macnaughtongroup.com
mor...@usaor.net wrote in message ...
>On Mon, 5 Oct 1998 01:03:30, Dave Fleming wrote:
>
>> Morg. gotta side with Doc on this.
>> To glass a hull is a real big job and needs careful attention to many
>> factors. Dryness of hull, condition of hull, environment of project,
>> level of skill of crew, proper materials.
>> Now no debate that some of the above are the same for a replank, but
>> reliance on 'goo' to revive a wooden hull that is need of a caulking
>> job is not my way.
>> Reef out, pay, cotton and then oakum if thick enough, set, paint,
>> putty, hull paint and in she goes.
>
>I view it as strictly a matter of economics. There are many wooden boats
>that aren't really rotten, but have many sister ribs, fastenings on
>their way out, loose deck, etc. Now to repair all these things with
>conventional methods could take thousands of dollars and hundreds of
>hours. A 36' boat, for example, in this kind of condition can be
>strengthened virtually to new condition by applying a mere 5/16" layer
>of glass consisting of four layers of 2 oz. matt and two of 24 oz.
>roving. The weight difference is not significant with most cruising
>boats. The cost for materials would be no more than about $2500.
>
>Regards,
>Morgan
macnaughton.com
edge! This is similar to seam repairs.
As far as trying to sheathe the outside and coat the inside. I have not seen
this work without removing the planking and replanking. Otherwise it never
seems to be possible to sufficiently seal the planking to prevent it from
shrinking and swelling.
Good luck to your friend. If this happens to be a wood that shrinks and
swells very little it might work well enough so that he can get by with
repairing a few cracked glue seams every year or so.
Sincerely,
Tom MacNaughton
Naval Architect
http://www.macnaughtongroup.com
Leo Edwardsson wrote in message ...
Paul H. Miller
A number of West Coast boats have had the splining technique done
successfully. They have mainly used fir as the splines and WEST system
epoxy. They arenšt hauled out annually, so they donšt dry out, causing
splits, or drying to the point where rot loves to grow.
Another technique that has greater engineering logic to it than covering
with glass, is to glue on two diagonal layers of cold-molded veneers over
the old planks, all the way to the deck. The advantages to this is that
you arenšt trying to have two materials fighting each other. In the glass
method the glass is about 4 times stiffer than the wood longitudinally, so
it will take a lot of the bending stresses (unless laid on the diagonal).
Most boats that have a łstiffness˛ problem are suffering from shear
problems caused by the breakdown of the caulking and loosening of the
fastenings. The diagonal layers solve this. Done right the two layers
are watertight as well. Also, since the material is wood, and is less
dense than water, the waterline level will change only slightly.
Some of the boats that have done this have left the interior painted. I
havenšt heard of any problems, but I would think it would be better to
strip it all down and slop some epoxy glop all round.
GVecere
I agree with morgan I glassed a 27" tong boat using Vaitses method . The boat
was glassed from wheel house roof to keel and the bilge never saw a drop of
rain or sea water. the only spot that did rot was where she got a tear in the
glass just under the rub rail from hiting the dock during a storm and rain
water from the deck was allowed to seep in for about 2 years (yea I know I got
lazy) .I no longer own her but know where she is and she still looks good.
Gregg Germain
: I'll say that most glass jobs are not done correctly to begin with and
: freshwater was allowed in the boat. That's where the trouble is, not in
: the glassing itself. There is nothing inherent in fiberglass that causes
: rot.
The problem with glassing is not rot. The problem with glassing is
that wood shrink/expansion cycles plus the way carvel planked wooden
boats work in a seaway means that the boat will be destroyed if you
glass it.
--- Gregg
"I don't want to die, baby.
gr...@head-cfa.harvard.edu but if I gotta die......
Smithsonian Center for Astrophysics I'm gonna die last."
Phone: (617) 496-7237 Robert Mitchum
MastNMate
Leo:
No glass sheating over carvel planks. Splines work ok on the topsides
but dangerous below the waterline. Find a good caulker, that's why the boat was
built that way.
GaryW http://www.mastmate.com
Gregg Germain
: >
: > The problem with glassing is not rot. The problem with glassing is
: > that wood shrink/expansion cycles plus the way carvel planked wooden
: > boats work in a seaway means that the boat will be destroyed if you
: > glass it.
: I don't understand what you're talking about. Please be specific about
: what you think will be destroyed and how.
: Regards,
: Morgan
When the wood dries out (if you haul the boat) and shrinks, that
stresses the wood because the epoxied surface can't' move as easily.
When a boat works in a seaway, the planks actually slide fore and aft
along the long edges: it's like taking a rectangular tube, holding it
at either end, and twisting the ends in the opposite direction.
But the fiberglassing does not allow the glassed side to move freely
so there's internal stresses created in the wood.
The fastest way I know of destroying a carvel planked, traditionally
built, wooden boat, short of piling it up on rocks is to fiberglass
the hull. Unless of course, you don't sail it in any but the nicest
days I suppose.
Leo Voorneveld -Netherlands
Thanks,
Why is it ok above and wrong under the waterline.
I am convinced that for normal boats do it the way it was build.
Unless that doesn't work.
In a case of a big gap between the planks you have to considera different
solution (maybe).
You can replank (costly) or (in your opinion only above the waterline) can
use a spline.
So I am curious about under the waterline.
The boats I splined I did with much care,working properly and no epoxy
(really hate that stuff for restoration, especially combined with glass
reinforcement) but a more flexible
glue.
And used a notable softer wood for the splines then either the frames or
planking,it
have to be the easiest compressed material.
For the people now accusing me for a epoxy hater,currently building with
epoxy and glass.
Newly build it is okay for me not to restorate,or you have to glass the
entire boat.
Regards Leo
Ron Ginger
......
> When a boat works in a seaway, the planks actually slide fore and aft
> along the long edges: it's like taking a rectangular tube, holding it
> at either end, and twisting the ends in the opposite direction.
> But the fiberglassing does not allow the glassed side to move freely
> so there's internal stresses created in the wood.
>
Im not sure this is entirely true. If the glass does make the surface
stiff enough to prevent it flexing, then there is no sliding, and no
force tearing the hull apart. Of course you can always supply enough
force to cause the stiffer surface to deform, but at that level the
traditional wood hull would also deform, probably even sooner.
So glassing a hull can very likely make it stiff enough to resit the
epected working load, and be an improvement.
The effects of dry and wet cycles would be a major problem, which is why
good epoxy construction calls for fuly enclosing the wood in epoxy. A
boat with just fiberglass on the outside of the hull, and bare (or even
painted) wood inside is not going to last. Even if the glass is nailed
on as in the Vitses (sp?) method. Glass it all, or dont glass any of it.
ron
Gregg Germain
: On Wed, 7 Oct 1998 13:24:12, gr...@sboat.harvard.edu (Gregg Germain)
: wrote:
: > When the wood dries out (if you haul the boat) and shrinks, that
: > stresses the wood because the epoxied surface can't' move as easily.
: Stress doesn't necessarily destroy anything unless it goes beyond a
: critical point. Hell, a plank is stressed quite a bit when it is bent
: around the frames during the building or repair process. Every part of a
: boat is under some kind of stress.
When you glass the outer surface, the shrinking either
delaminated the glassing (not likely but possible) OR the stress is
moved to other components and fractures start to occur.
That stress has to go SOmeWHERE and it's a stress that wasn't on the
planks/frames before it was caluked because then it could move freely.
EVer see what happens to frames with an overcaulked boat when the
wood swells up? The stress fractures the frames across the grain.
Now when you are glassing a boat you are doing it under one of two
cases:
1) The boat is dry.
- in which case there's a gap between planks, the boat
goes in the water, the planks swell (because you can never glass it
well enough to keep all moisture out plus (if you don't glass the
topsides the caulk will wick moisture to the lower planks and they
will swell), and now that stress will do the same thing as if the
seams were overcaulked.
2) the boat is wet
- in which case I don't see the glass holding that well.
: I really doubt there is any significant movement.
Your doubts are faulty.
If what you're saying
: is true then we ought not tighten the plank screws since that would
: interfere with the fore and aft movement of the planks
In fact the beveled heads on the screws act as inclined planes
which when the planks slide fore and aft, tighten the plank against
the frame.
: I would really like to see some real evidence of what you're saying,
: because I have seen a many glassed-over wooden workboats that probably
: saw more stress in one week than the average yacht would ever get in
: twenty years, yet they seemed to be unaffected by this problem you are
: so concerned about.
Just wait. However I will admit that those working boats - if
you are talking about fishing boats, are much stronger built with much
largert scantlings than a pleasure craft and can take more stress.
Gregg Germain
Hi Ron - long time no see.
: Im not sure this is entirely true. If the glass does make the surface
: stiff enough to prevent it flexing, then there is no sliding, and no
: force tearing the hull apart.
The hull stresses are there whether the plank slide or not.
If they can't slide the stress has to go SOMEWHERE. And it'll go to a
place you don't want it to go..to a place the boat was not designed to
resist.
: The effects of dry and wet cycles would be a major problem, which is why
: good epoxy construction calls for fuly enclosing the wood in epoxy.
I doubt you can ever get a 100 percent enclosure.