Building 72' schooner in Viet Nam

[Lucky Luke]

CSM is going to gobble up epoxy.

That's the aim: build an epoxy barrier coating, and give a bit of protection to the wood against small scratches, not to reinforce the hull in any way, or give any real protection. What does a total of 30oz./sq/yr change to 2' of planking backed by 4 x 5 laminated frames every 16'? And what protection against shocks would be needed for a 75 tons vessel: pretty thick I'm afraid! Well: the wood, nicely bouncing, does that quite well all by itself...up to a point,of course!
This is still undecided, though, but I do not feel inclined to using expensive polyester, but rather quadri-axial or double bias or satin...or simply build up with CSM as I said: 5 to 10% difference in glass/ resin content, and no excessive rigidity. Not significant difference between them all. "Epoxyworks" (West System) opinion seems mitigated, too....
Largest boat using West System (700 tons, 3 masted barque Tenacious) is sheathed with about 100oz./sq/yd of woven and quadriaxial fabric (5 layers) over her 3' thick planking. No CSM.....

[Candyfloss]

Sorry Luke, I have to do that in Metric.
1 ounces per (square yard) = 33.9057475 grams per (square meter) (Wikipedia)

Call that 34*100 is 3,400gsm total layup. 3 layers of 1200gsm cloth, the heaviest stuff I ever worked with!

Your 30oz layup however is only 3 layers of 300gsm; mere tissue paper. Easy peasy. A good gang of guys you'd glass the whole boat in a couple of days.

And now I see your reasoning, I'm with you on the csm.

[py]

Fantastic, and thanks for coming back

[RFNK]

Luc
Where is the timberyard in your pictures? Did you order these teak logs in from Burma or is there a timberyard near HCMC that already has these? There's a timberyard in Hanoi that has a big sign advertising teak (and MDF) but when I investigated all they actually sell is plywood and mdf for office furniture - no teak at all. Rick

[Lucky Luke]

Luc
Where is the timberyard in your pictures? Did you order these teak logs in from Burma or is there a timberyard near HCMC that already has these? There's a timberyard in Hanoi that has a big sign advertising teak (and MDF) but when I investigated all they actually sell is plywood and mdf for office furniture - no teak at all. Rick

I called it a timberyard but it actually it is not: this was a favor from the owner of a very large furniture factory to let me buy some wood from him. They import hundreds of logs yearly for garden furniture , and did let me choose in their stock. There is nobody using teak wood in Vietnam for other purposes, and it all gets exported ........

The teak you will find in Vietnam besides that is mostly smuggled teak cut in the forests of VN or Laos. Although very dense and close grain, it very often is very bad at heart, and they cut it in short lengths for easier transportation ....!

[RFNK]

Thanks Luc! I'm looking forward to seeing how you do the deck of the schooner. Will you run the planks straight or bend them, and will you sheath this deck? Rick

[Lucky Luke]

But, after all these discussions, let's continue about the construction!

As framing and then planking was progressing, also was the deck structure.

You can see there, between the frames, the foredeck beams all in place:



There is, on Ted Brewer's "Tree of Life" design, a very long roof over the forward cabins and salon/ galley, then a short flush deck, then the wheelhouse followed by the aft cabin's roof.
You can see there, between the frames again, the beams of this short flush deck:



Right aft of the wheelhouse, the deck is raised and becomes a poop deck. Here are two big beams, the lower one being the after-most of the main deck, the higher one the foremost of the poop deck. These correspond to the aft engine room bulkhead, which will rest on the additional frame you see there:

[Lucky Luke]

Finally, about six months later (December last year), a party was organized as the planking was finished, and also the first layer of deck and the bulwark.
The scaffolding were taken away, and the beauty of this hull revealed:





A couple of bits of wood were put at the bows, "symbolizing" the bowsprit and jib-boom:

[Lucky Luke]

Thanks Luc! I'm looking forward to seeing how you do the deck of the schooner. Will you run the planks straight or bend them, and will you sheath this deck? Rick

Deck planks will be bend: that is why I cut the teak for rather narrow planks: 60mm. when finished, 16mm. thick. They will follow the curve of the cabins sides, and not the gunwhale, meaning they will be holly-splined to both the king planks and to the gunwhale at the bows. Their width will also be slightly and gradually reduced towards both boats ends: old high class English way: consumes a bit of teak but is supremely elegant!

However, that is not for immediate future but close to the end: it is a finishing task I do not want it to get damaged by accident, neither left for maybe a couple of years (?) under a protective ply!

Underneath the teak planks will be three layers of 12mm. plywood (that is going to be done in a few weeks), then a light fiberglass sheathing in continuation with the hull sheathing.

Later, teak will be glued only to the underlying deck.

[Lucky Luke]

Sorry Luke, I have to do that in Metric.
1 ounces per (square yard) = 33.9057475 grams per (square meter) (Wikipedia)

Call that 34*100 is 3,400gsm total layup. 3 layers of 1200gsm cloth, the heaviest stuff I ever worked with!

Your 30oz layup however is only 3 layers of 300gsm; mere tissue paper. Easy peasy. A good gang of guys you'd glass the whole boat in a couple of days.

And now I see your reasoning, I'm with you on the csm.

Mmmmmhhhh.... I do the effort of converting everything in Imperial for our mostly Anglo-American friends, and now you translate in Metric...??!!? I think I 'm going to give both, that will be clear for everybody!

But sorry if I made me misunderstood about the sheathing on "S.V. Tenacious": this is 100 oz/sq/yd TOTAL: I mean just as little compared to the whole boat than what will be done on this one!

[RFNK]

Thanks Luc, and thanks for the latest batch of pictures too! It really is looking beautiful already. Rick

[Candyfloss]

Rick, that is the understatement of the year mate. That boat is absolutely bloody STUNNING.

[Lucky Luke]

You will have noticed that the filler on the fastening of the planking are a different color below and above waterline. The owner originally wanted to keep open the option of a varnished hull, idea which was abandoned when he saw the vary different colors of the wood from various trees , although being all of the same specie , and this is why fastenings have epoxy/carbosil filller over them below waterline, and wooden dowels above.



The offset of the dowels is due to a short scarf joining the butts of planks:





You can see through the stern ports (no guns intended there) the lamination that makes the upper part of the stern frame:

[Larks]

Luke she is looking great. Because you have used meranti planking are you likely to vaccum the resin/glassing process to improve the saturation of the planking or is that only something that is done with foam core hulls?

[Lucky Luke]

THE CREW:

"A tout seigneur, tout honneur!"

Here is part of the gang who has built this boat so far:
On the right, with his wife, is Mr. Trung, the foreman.




and some offspring, future heart breakers:



They are all the nicest guys you can meet, and extremely keen on learning new boat building techniques, which are very different from what they are used to do: here is Trung's brother boatyard, also in Vung Tau:







Did you say: "rough"?....

[Lucky Luke]

Luke she is looking great. Because you have used meranti planking are you likely to vaccum the resin/glassing process to improve the saturation of the planking or is that only something that is done with foam core hulls?

I cannot really imagine encapsulating that whole hull (with all it's shoring) for vacuum and sort of "scrimping" of the epoxy into the wood....!

Inside , before putting on the first ply of the "new" decking (you will see later...!) all interior including beams, stringers, beam shelf and the blocking at deck line will be impregnated with International Everdure, which is a very thin, low molecular weight epoxy, first diluted at 50% (thinner than water!) up to refusal, then diluted 20, 30% one or two hours later, and then pure. This is epoxy impregnation, and a lot will be sucked by this porous wood. After impregnation, inside will be polyurethane varnished or painted, depending on areas. Silly thing is that much of the bilge has been abusively "fiber-glassed", using 50 gallons of West system epoxy! No real harm but useless waste of material!

Outside will have "West System" epoxy barrier coating and light fiberglass sheathing up to deck line, as will last deck plywood. Hull will later be polyurethane painted (Awlgrip system). Never change a winning team!

[Larks]

I'm not really that familiar with the whole vaccum process but from what I have seen over a foam core I don't think there is a need to encapsulate the whole hull. I think you could do one side at a time, though the bracing timbers would get in the road, by covering the epoxied area with peel ply, suction line system over that and then plastic sealed at the edges with what looks like blue tack to create the vaccum seal.

But as you say, I don't know if there is any value in the process with the meranti planking anyway. It may not soak in any more than it would otherwise by normal appication and I guess without an interior "mould" it possably wouldn't vaccum that well anyway.

[Saltiguy]

Amazing!
Thanks again

[Lucky Luke]

DECKING:

The first layer of decking (let's call it the "under-deck") was on at the time of this party, and the owner, Derek, could proudly stand on it....not for long alas, as the continuation of the story will show you later...!



This under-deck was made of 18mm. meranti. The bulwark (which was not to going be there for long either...) had been planked, and a stringer added at half height.





Looking smart, for sure!:

[Lucky Luke]

Below deck is equally good looking, with the varnished laminated beams and superb carved knees, made of old rosewood (from typhoon fallen trees, years before).

Here is the aft cabin, looking aft:



The salon, looking aft, showing the main mast knees between reinforced frames and beams:





And those at the main mast-hole:

[Larks]

not for long alas, as the continuation of the story will show you later...

I shudder to think what is coming

[Lucky Luke]

I shudder to think what is coming

...and you are right!

But before discovering the "unpleasantnesses", we discussed, with Derek about increasing the size of the flush deck area in front of the main mast , providing deck space for large dining table over the skylight, or for eventual dinghies (or jet-skis...) each side. You can see here that space is rather tight for large parties on sistership "Tree of Life".



Derek also wished to have a direct access to the aft cabin from the wheelhouse instead of through the passageway on Starboard along the engine room (please refer to the GA on first page of this thread), which would rather be converted into a laundry (mind that this boat is intended for eventual charter). This meant lengthening the wheelhouse aft in order to provide space for a companionway down to that aft cabin.

Then we did some renders to show how this extended wheelhouse and shortened roof would look like:



Compared with original "Tree of Life:



The counter had, fortunately, been slightly extended too as the transom had been built less vertical, and as all was looking good, it was agreed to destroy part of the first deck layer in order to do these modifications.

Here is the original deck structure:



And the re-designed one, showing the deck space that had been gained. Some below floor space was lost, but this allowed also to have the whole salon/ dining/ galley at the same level:



At least, we would also be able to rectify a quite funny mistake: the structure for the companionway from the wheelhouse down to the salon had been ...forgotten!!!. It should have been aft of the main mast hole, just besides the opening for the passageway (picture shows aft salon bulkhead, looking aft to Starboard side)

[Lucky Luke]

please refer to the GA on first page of this thread

Sorry, I forgot this was not clearly visible on the posted G.A.: this passageway between salon and aft cabin is below the quarter berth, which is in the wheelhouse, on Starboard.

[RFNK]

So Luc, the nice looking deck we saw earlier was altered because the owner changed his preferences or was there something else as well? What structure do you mean was forgotten? Is the structure a bulkhead, some sort of pillar arrangement, a ring frame or something else?

By the way Luc, I had a look around to see if I could find a Fein Multimaster in VN as I thought it may be cheaper than in Oz. The only supplier, I think, is in HCMC and the price for the Fein MM ... Top kit is 244EUR. This compares well with prices in Oz but perhaps not with prices in la France (?). Anyway, I think it's a pretty handy tool for boatbuilding so I thought I'd mention it. They're delivering one to me in Ha Noi in a week or so.

STILL no sign of me getting out of Ha Noi for a while although i have a trip to Hue coming up soon.

Rick

[Saltiguy]

Thanks once again for this wonderful thread!

[TR]

The changes look good Luke, the full length clamp is especially good and I would add another couple of strakes to the bilge stringer as well.

I was aboard "The Tree" many years ago and the arrangement of the galley/saloon was a bit odd. The saloon sole extended forward under the trunk and it seemed like there was about 9' of headroom. The forward stateroom bulkheads went up...up...up, forever! I believe the only way into the main accommodation was in the little side doors in the pilothouse, I hate that and would insist on a proper companionway forward of the pilothouse. The pilothouse is small and becomes a continuous bottleneck with a bunch of guests aboard, eating on deck, etc.

That passage between the forward guest cabins was quite dark and people were endlessly stumbling down the steps in there. Your addition of skylights might help with that.

Good work making the side decks wider all around.

Also I don't like deckhouses that get wider forward, I would rather the pilothouse sides were parallel with centerline. But I know you are fighting interior requirements. Big boats offer many choices but it still comes down to juggling inches.

[Lucky Luke]

So Luc, the nice looking deck we saw earlier was altered because the owner changed his preferences or was there something else as well? What structure do you mean was forgotten? Is the structure a bulkhead, some sort of pillar arrangement, a ring frame or something else?
Rick

After discussions with the owner, it was decided to alter the deck design, meaning re-doing some of it, not to take it off completely.

What had been forgotten are the two short girders each side of the "would have been" companionway from the wheelhouse down to the forward accommodation and that support the two parts of the deck beams which are interrupted to create this companionway!

But actually, that - together with some defects I shall show you later (have all been rectified!) - illustrates why there is a need for somebody to guide the crew. And this person must be used to other construction techniques than those the Vietnamese master well for building their fishing boats, for example, like those in the yard I showed in earlier post. That is what I do now with my design office crew, producing multiple construction drawings to complement the general architectural drawings of Ted Brewer.

The hull had been nicely and solidly built, happily, but finally the deck had to come off entirely. You will see why later.

[RFNK]

Thanks for that Luc. So, I gather, the situation now is that you don't personally get in there and shape timber etc., rather, you look at what needs to be done, put together construction drawings of this work, explain to the builders what to do, and how to interpret the drawings, I guess, and, from time to time check the work, advise on changes that may be necessary, etc. Is that about right? By the way, I also think the changes to the original layout look really nice. Rick

[Lucky Luke]

The changes look good Luke, the full length clamp is especially good and I would add another couple of strakes to the bilge stringer as well.

I was aboard "The Tree" many years ago and the arrangement of the galley/saloon was a bit odd. The saloon sole extended forward under the trunk and it seemed like there was about 9' of headroom. The forward stateroom bulkheads went up...up...up, forever! I believe the only way into the main accommodation was in the little side doors in the pilothouse, I hate that and would insist on a proper companionway forward of the pilothouse. The pilothouse is small and becomes a continuous bottleneck with a bunch of guests aboard, eating on deck, etc.

That passage between the forward guest cabins was quite dark and people were endlessly stumbling down the steps in there. Your addition of skylights might help with that.

Good work making the side decks wider all around.

Also I don't like deckhouses that get wider forward, I would rather the pilothouse sides were parallel with centerline. But I know you are fighting interior requirements. Big boats offer many choices but it still comes down to juggling inches.

Hi Tad,

I feel uncomfortable saying that Ted "should have" designed this boat with a full length clamp since sister-ship, Tree of life, built this way, has done a quadruple circumnavigation and encountered some nasty weather without problems, but I very much more like this full length clamp, anyway! Edited to say: that was decided by earlier builder

There are two more full length bilge stringers, as you see on the pictures (not drawn on this structure drawing), well located and that will give superb rigidity.

I could not agree more with you about the "oddity" of the original salon/ galley/ forward cabins arrangement. The new flush deck over the whole salon/ galley will reduce this headroom to something more normal, and there will be some side view through a couple of portholes each side and light and ventilation from the skylight above. The sheer, though, will still give a high headroom in the forward part of the salon (2m.23 - 7'4"- below the foremost beam!), but I still kept the superstructure over the forward cabins and not extended the flush deck forward any more, which could have been done, mainly because this superstructure will be a wave breaker protecting the big and exposed wheelhouse. This gives a somehow crazy headroom in the guest cabins whose floor I have to keep at the same level as their en-suite bathrooms, which are not below the trunk. G.A. is being modified and the boat will have one cabin each side of the (also super-high but now well lit) passageway forward.

The access to the whole accommodation, excepted crew's quarters, is still through the wheelhouse, but that is how the general architecture of the boat has been drawn, and I cannot put another companionway. At least now there is one, and also wider than original design...!!!

I am doing some major changes, though. One is that the wheelhouse is a bit larger (longer), and the access will be through wider, watertight, sliding side door each side, the exposed front door being suppressed. This way, there will nearly always have a leeward door open, which I like very much. It does not change the "wheelhouse bottle-neck" issue, but in practice much life is outside, including the steering (from the former skipper of the "Tree") , and only the galley up-down is constant. She may cruise the North Sea someday, but will certainly spend more time in tropical waters!!!

About the wheelhouse shape, I will not follow the original design which I find extremely wide and flat forward :



Instead, I will narrow it forward (narrower than the carlins that have been built) and also make large radius forward corners. Will loose a few inches, as you say, but that is the constant trade-off, isn't it?

[WX]

Big...and impressive. Looks like a very well organised yard.

[Lucky Luke]

Thanks for that Luc. So, I gather, the situation now is that you don't personally get in there and shape timber etc.

I DO shape timber too! I have cut a few bits and pieces of wood in my life (and a few fingers), and we all have our ways to do things. That is what we share and show each other. But I effectively mostly provide detail drawings and go there just once or twice a week, cause I also have to take care of my other clients and boat designs!

So: back to work and enough time spent here today, folks! See you later

[J. Dillon]

Fantastic!! What a project. Bravo.

JD

[Lucky Luke]

Thank you all for the interest you are showing in this effectively fantastic wooden boat construction, and to our Maaaaaster of the Web for having stickied it a bit so that more people will notice. I am happy to be able to spend a bit of time in making this thread as I think it will be of interest to many.

But, as one says, we learn through mistakes! Not necessarily our mistakes - although they are the most remembered - but also through others...and alas one day - maybe - their dramatic consequences!

I have hesitated in revealing what follows, as I do not want this fine schooner to earn a bad reputation even before her birth, specially since all the defects that follow have now been entirely rectified the way it has to be done, in spite of giving the unpleasant feeling of going backwards.

Let me say, however, that this is not reproaching anything to the crew of nice Vietnamese craftsmen who are still working on this boat, since they are used to short lasting fishing boats (twenty years max) using long lasting timber (and some parts get re-used for over a hundred years) and where some gaps and voids do not matter that much. These boats will be permanently soaked in nice wood preserving salt water, and anyway all surfaces well painted with red lead:



This does not matter in such boats, but does in construction like this one, using epoxy impregnation of porous woods and plywood, but that are still intended to last a hundred years. This is what I hope for this fine schooner.

But since, as I said, we learn from mistakes, here is a:

MANUAL OF WHAT NOT TO DO IN WOODEN BOAT BUILDING

As it had been decided to alter the deck design, we started pulling off the deck planks over the area that was going to be modified, and I was expecting much difficulties from the PU gluing of this first deck layer onto the beams and top of planking, not really understanding why the boys said: "no problem".

There was no glue! Only an ordinary varnish! This first decking was of 18mm. meranti, tongues and grooved, and held down with bronze nails. It was to be covered by two layers of 12mm. ply, and then the final caulked decking.
It was then intended (?) to be fastened to the beams by screws through the last layer, and somehow caulked at the hull/ deck junction...?
But a boat built like that would then suffer a lot at this junction, which would be the weak part between two rigid elements: the double planking all glued hull, and the plywood reinforced deck. Sure leaks!

So: off went the whole deck!

Voids! The higher beam at the start of the poop deck, the end of the poop deck beam shelf, and the poop deck second planking cut a bit....short:



The double beam at the engine room bulkhead, the double plywood (with nicely epoxy impregnated fiberglass in between) but with unprotected edge - and lower than the beam:





Not the best assembling: or the beam is in front of the frame, which is necessary when there will be a hanging knee, or, in this position,: the beam shelf better be bolted (or riveted) to the frame, the beam to the beam shelf, but also the beam extended besides the frame and bolted to it, making a sort of "triangle". Happily this boat, with it's double 18mm. ply bulkheads, and it's multiple hanging knees is still very rigid:



A hidden little work of art, but also a future leak at the inner corners of the bulwark stanchions:

[Lucky Luke]

At the bows: deck structure not faired:



...but also a part of king plank missing right behind the stem:



....and a sort of little bulkhead, forward of the chain locker, and then a big, totally enclosed void:



I had feared, during previous visits, that there will be some non ventilated spaces behind this chain locker lining.



This chain locker was accessible through an opening in the collision bulkhead (which, by rule, has to be solid!
Collision???....which collision?)



So, I asked for a couple of holes to be cut below this chain locker, and then....: off goes the chain locker lining!
Below it: the two stringers, breast hook (and space below), frames and floor in another entirely enclosed space:

[Lucky Luke]

"INTO THE VOID" could have been the title here.

At the stern, this was quite bewildering!

What looked, before the deck was taken off, like big solid wood above the stern frame nice big lamination was in fact....a box! ...with some little bits and pieces of wood here and there, and the deck just "touching" the stern bulwark for future leaks in these voids... sure rot in two months!







Allez! That's all boys! Let's do some repairs now!

[dhic001]

Fascinating thread, thanks for posting.
Daniel

[Lucky Luke]

So, after taking the whole deck off, we started the repairs and alterations.

The first job was to put thousands of little pegs into all the nail holes:



...and then to fill up all the voids around the stern with well adjusted pieces of wood. Certainly not as nice as one solid piece, but equivalent as far as "avoiding voids" is concerned!:



The other large void at the bows was filled with tar and sheathed with epoxy+ CSM. Epoxy and tar actually "work" together pretty well. Before that, a piece of hard rosewood was added behind the stem piece to transfer the compression back to the king plank.



At the same time, new beams and girders, all laminated, were made for the new deck extension:



The existing girder, which had to be kept but made shorter for the reduced cabin had been ...cut short on one side (Oh, the boy was soooo sorry!....but who does not make mistakes?), and they had to do a new one and assemble the side deck beams on it :



Then all the new beams and skylight girder were put in:

[Lucky Luke]

The forward salon bulkhead, separating from the forward cabins, could then be made of two x 18mm. ply with epoxy/ WR in between (like all other structural ones), and fitted against the new beam and adjoining frame. Later, the access to the corridor through this bulkhead will be cut, and fitted with a watertight door (normally kept open). The door and bulkhead between the forward guest cabins and the crew's cabin are also watertight , as well as between the engine room and salon, and between engine room and aft cabin. Together with the collision bulkhead, that makes a total of 5 compartments. That is well above the rules for this class of vessel, but will comply to the most stringent ones for damaged stability!



All holes were filled, and extra blocks of wood glued in between the beams inside the bulwark stanchions, providing a large gluing area all around stanchion bases, in order to stop leaks at the inner stanchions edges. You can also see here the deck reinforcements and knees at the level of the main mast chain-plates:



All the deck was then faired, showing a nice, clean job. Here around the foremast-hole:



and around the new skylight:



Nice deck, isn't it?

[peter radclyffe]

what grade of plywood do you use

[Lucky Luke]

what grade of plywood do you use

Not the best stuff the plywood industry can offer, but the best available here. A boatbuilder friend of mine had done some tests: surprisingly good, actually: left in the open, on the ground for about five years, not only it did not delaminate ( that is easy to check with a pressure cooker), but there was only little of it eaten by insects, and practically not rot.

This is B grade, formwork ply, resorcinol glued, but in a wood you will not have outside of Vietnam: botanical name: styrax tonkinensis. This wood looks lousy and not better than wood for matchboxes, but it takes the glue well, and is stable. I would say better than okoume. Faces are good, without defects, and only few voids inside. Mechanically, though, it is quite poor, and I would not rely on structural screws into it.

[RFNK]

Luc
In several provinces in VN but especially in Bac Ninh, I see sheets of timber veneer laid out to dry along roadsides and river banks, often covering several acres. The quality rarely looks good enough for finish veneer so I'm wondering whether this is used for plywood - it would make sense to me, and I'm wondering whether this may be the timber you refer to above. It's a light colour, maybe just slightly darker than radiata pine, but I've seen some that's almost white. Do you know where the plywood you're using is made and whether it's made in various places? Rick

[cookie]

That's the aim: build an epoxy barrier coating, and give a bit of protection to the wood against small scratches, not to reinforce the hull in any way, or give any real protection. What does a total of 30oz./sq/yr change to 2' of planking backed by 4 x 5 laminated frames every 16'? And what protection against shocks would be needed for a 75 tons vessel: pretty thick I'm afraid! Well: the wood, nicely bouncing, does that quite well all by itself...up to a point,of course!

I had not read this when I started digging into the mechanical data and properties for materials quest, but it is in line with what I was thinking. Not that I am an expert on the matter though.

However, wouldn't quadri-axial or double bias introduce a lot of rigidity, contrary to what I think you are stating below?

This is still undecided, though, but I do not feel inclined to using expensive polyester, but rather quadri-axial or double bias or satin...or simply build up with CSM as I said: 5 to 10% difference in glass/ resin content, and no excessive rigidity. Not significant difference between them all. .....

[Lucky Luke]

Luc
In several provinces in VN but especially in Bac Ninh, I see sheets of timber veneer laid out to dry along roadsides and river banks, often covering several acres. The quality rarely looks good enough for finish veneer so I'm wondering whether this is used for plywood - it would make sense to me, and I'm wondering whether this may be the timber you refer to above. It's a light colour, maybe just slightly darker than radiata pine, but I've seen some that's almost white. Do you know where the plywood you're using is made and whether it's made in various places? Rick

Yes, what you see everywhere is veneer for plywood, of which Viet Nam exports a lot. It is often Styrax ("go de" - with a bar across the "d" and a "s" above the "o"), but also lousy poplar, fast growth eucalyptus (more often used for paper) or white rubber tree wood (hevea). Styrax and poplar are very clear, nearly white. People slice it into veneers with very primitive machines as it "unrolls" (???.. "deroule" in French...?) very easily.

After that, they sell it to plywood factories - and there are LOTS of them all over the country - and, just like for everything here, you have the best and the worst. Some do melanine gluing, leaving huge voids as they do not cut the sheets of veneer properly and sometimes let them overlap and just apply pressure - krunch! - while some assemble their veneers carefully and do good resorcinol gluing. The faces, anyway, look awful, not that they are bad: it's just the wood itself that is not nice, and it would be out of question to leave them visible: they will all be "panelled".

I have not done the final selection of manufacturers for the decking ply, but I have three highly recommended ones (near HCM area: Dong Nai ) that I shall visit soon. I will let you know the outcome.

[Lucky Luke]

I had not read this when I started digging into the mechanical data and properties for materials quest, but it is in line with what I was thinking. Not that I am an expert on the matter though.

However, wouldn't quadri-axial or double bias introduce a lot of rigidity, contrary to what I think you are stating below?

You've got to the core of the problem: The epoxy from West System, well adapted to the purpose for which it is made, remains (slightly!) flexible and allows movement of the hull without cracking. Mind that I said movement of the hull - whether it is steel, alloy, "the other material", or wood - not movement of the wood by absorbing water, which is what it is supposed to avoid or at least limit.

The fiberglass - or else - is there to allow building up a thick enough barrier, and to protect against some mechanical aggression better than the only epoxy would. It is then contradictory to use high modulus fibers, and that is why I am more than inclined to use CSM, whose short fibers will move inside/ together with the epoxy while WR or other long fiber fabrics will not allow much movement and rigidify the sheathing. As this sheathing is mechanically nil compared to the power of the wooden hull structure, I am afraid it may just part away from it - or break. If I cite quad or double bias as eventually usable is because their multi-direction weaving is less prone to induce excessive rigidity in one particular direction as WR would, and also is easier to put on a compound curve surface.
I am waiting for opinions from West System (the Gougeon bros Co.) manufacturers on this, for this specific boat and this specific wood. Will let people know, but in the meantime I just hope that this thread will not derail into this discussion about the sheathing, which is just a minor part of the whole construction...which is far from finished!

[George Ray]

Wonderful project and best wishes and congratulations!
thanks for sharing,

Glass Sheathing:
I understand from a fisherman friend that a method used to sheath old wood hulls is to trowel on 3m5200 and then press/stick woven roving into it. When the 5200 has firmed up the overhead layup begins. Always made sense to me as the best way to ensure a bond between wood and glass.
Non-glass Alternative:
Several coats of creosote and then copper sheathing.

[RFNK]

Nice deck, isn't it?

Hmm, forgot to mention it! Really beautiful!! Rick

[Eric D]

Luke,

As mentioned by many, very inspiring!! Thank you for the time it takes to share this build with us.

Eric

[floatingkiwi]

( quote)I am waiting for opinions from West System (the Gougeon bros Co.) manufacturers on this, for this specific boat and this specific wood. Will let people know, but in the meantime I just hope that this thread will not derail into this discussion about the sheathing, which is just a minor part of the whole construction...which is far from finished![/quote]

When you have finished the deck sheathing etc and then move to another problem, so the topic of discussion will change.
When people discuss things you are doin' on your boat, they are worrying about how the method or material list can be applied to their own boat. They don't really care about your boat, in fact some might hope parts might fail,( without of course endangering folk), so they do not make the same mistake or have already taken a more difficult route only to find they didn't need to.
Even myself, I think I am reading this thread to admire the putting together of a magnificent vessel and all the hardship and worry it must incur,well I am, but mostly I am thinkin' about how small a problem I have in finding good marine ply on the cheap here in the good ol USA, compared with what you are faced with, sheez.
Well done and good luck and if you need any help, gimme a call.

[Lucky Luke]

Glass Sheathing:
I understand from a fisherman friend that a method used to sheath old wood hulls is to trowel on 3m5200 and then press/stick woven roving into it. When the 5200 has firmed up the overhead layup begins. Always made sense to me as the best way to ensure a bond between wood and glass.
Non-glass Alternative:
Several coats of creosote and then copper sheathing.

Interesting! Certainly very good way to do for making old, carvel planked boats watertight and protect them against marine borers! I would perhaps question the adherence, after that, between the polymerised 5200 and future fiberglass sheathing...? Cured 5200 paints well, but will new sheathing glued well onto it...? The WR that is still sticking out may do the "mechanical interface"...? Something to be kept in mind for this kind of work, anyway. Thanks.

Very expensive, though!!!

Creosote, or various tars and other mixtures + copper sheathing is something I have advocated for a long time, but no more! Not only its cost has become prohibitive, but it causes a lot a problems with neighbors in marinas (I can tell you: it does: up to being "kindly" requested to go somewhere else by the harbor master!), does not finish with a surface as smooth as one wishes nowadays, is not that performing as antifouling, and also does not protect that well either: Even 99.9% "electrical" copper corrodes at waterline, gets damaged quite easily leaving entry for worms, and has become difficult to repair: no more nails, no more tarred paper (or felt)!

But oh! She was absolutely gorgeous, on the yard, with this shiny brand new copper!

[Lucky Luke]

When you have finished the deck sheathing etc and then move to another problem, so the topic of discussion will change.
When people discuss things you are doin' on your boat, they are worrying about how the method or material list can be applied to their own boat.

Well done and good luck and if you need any help, gimme a call.

Thanks for the offer

Well... I might have become a little too sensitive after seeing the way the other thread I had started about that boat had derailed. Anyway, I try to spare time for answering to most questions and keep this thread running, as I know that many folks are mostly investigating all around this forum about the best methods, products etc...for their own boat. Me too! That's the idea of this nice WBF!