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Plywood?
Can you use any kind of plywood for boatbuilding ort does it have to be
marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? |
exterior AB (ABX) is often used, depending on the design and what is called for
in the bill of materials by the designer |
Marine BS1088 or similar standard ply will get you better quality
plywood with no voids between the plys. Marine ply, Okuome specifically, is lighter than what you can get at the Home Depot. So if you're building a small boat like a canoe where weight is a concern, it's a nice option to go with. -- Matt Langenfeld JEM Watercraft http://www.jemwatercraft.com/ Mike wrote: Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? |
Given the same quality of construction, in many situations marine plywood will last longer and require less maintenance, but you pay more for it. So there's a cost vs longevity tradeoff. For example if you are buildign a large boat which will be in the water all the time, or a small boat which is left outside on a trailer, and you want ot pass the boat on to your children's children, then marine plywood would be cost effective. If you are building a small boat like a canoe or kayak which is only in the water a few days a year and is stored indoors, say hanging from a garage ceiling, the rest of the time, then marine plywood would not likely be cost effective. As a rule of thumb a marine plywood boat will last 25 years while a non-marine plywood boat will last 10-15. On larger boats where weight isn't so improtant, at least 3 layers of "fibreglass" on the hull turns a plywood boat into a "fibreglass" boat and can increase its lifespan, with ocassional resurfacing, indefinitely. Exterior grade meranti (or lauan) weighs the same as marine grade okume (half a pound per square foot for the 1/5 inch plywood commonly used on small boats). Here in Ottawa the meranti is $14 a sheet while the okumne is $50. Meratni is stable unlike exterior grade douglas fir plywood which swells and shrinks with changes in heat and humidity and developes surface cracks (called "checks") on the surface which spoils the appearance, especially if stored outside in the sun. Fir plywood pretty well has to be covered in moderately thick fibreglass to stop the checking. I'd avoid the virola underlayment sold at Home Deopt in this area. It is the grey sapwood, not the white heart wood, and does not last. I tried it on a small boat (Delta on my website) and have had to do more maintenance than on the two lauan boats I have. Meranti has replaced lauan in this area. The quality is much better, no edge voids and both sides smooth. If selecting meranti try to get sheets without any surface splits filled with wood filler. -- ------------------------------------------------------------------------------ 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 |
I think Okuome is much lighter.
William R. Watt wrote: Exterior grade meranti (or lauan) weighs the same as marine grade okume |
Meranti is about 25% heavier than Okoume but considerably less expensive and
a good bit stiffer and more impact resistant. I use okoume when weight is at a premium and meranti when strength and price are more important. It is hard to tell the difference between BS1088 and 6566 other than price. 1088 has thinner plys when you get past 5/8" and the face veneers are a bit thicker. 1/4" ACX has 3 plys and may have voids, face plugs on the A side and open knots on the C side. 1088 and 6566 have 5 plys and clear faces. "Matt Langenfeld" wrote in message k.net... I think Okuome is much lighter. William R. Watt wrote: Exterior grade meranti (or lauan) weighs the same as marine grade okume |
In "New Plywood Boats" TF Jones gives the weight of 5mm okume marine plywood as 1/2 pound per square foot, which is the same weight as lauan underlayment which I think is 5.22mm. They may not be the same thickness but would be substituted for each other in small boats. In "Dingy Building" Richard Creagh-Osboren gives the following weights for boatbuiding timber, not plywood, but probalby close enough .. okume 25 lb/cu ft lauan 37 lb/cu ft meranti 25-45 lb/cu ft I thought meranti was a type of lauan but I was wrong. Like lauan, meranti seems to be a species of tree with different varieties used, two mentioned by Creagh-Osborne are Borneo red Sereya and Oba Suluk. Confusing for the boatbuilder. For comparison, douglas fir is 33 lb/cu ft the above weights are within a pound of what is listed in "Skene's Elements" for the one's given in Skene's. not all are there. -- ------------------------------------------------------------------------------ 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 |
http://www.worldpanel.com/Marineplywoods.htm
Scroll down to the 2nd chart. I've used their products and found their published information to be accurate. William R. Watt wrote: In "New Plywood Boats" TF Jones gives the weight of 5mm okume marine plywood as 1/2 pound per square foot, which is the same weight as lauan underlayment which I think is 5.22mm. They may not be the same thickness but would be substituted for each other in small boats. In "Dingy Building" Richard Creagh-Osboren gives the following weights for boatbuiding timber, not plywood, but probalby close enough .. okume 25 lb/cu ft lauan 37 lb/cu ft meranti 25-45 lb/cu ft I thought meranti was a type of lauan but I was wrong. Like lauan, meranti seems to be a species of tree with different varieties used, two mentioned by Creagh-Osborne are Borneo red Sereya and Oba Suluk. Confusing for the boatbuilder. For comparison, douglas fir is 33 lb/cu ft the above weights are within a pound of what is listed in "Skene's Elements" for the one's given in Skene's. not all are there. -- ------------------------------------------------------------------------------ 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 |
Meranti...
Use it if you will. But remember that your boat is contributing to deforestation in Borneo. Your pleasure... will be at someone's cost. Nicholas "William R. Watt" wrote in message ... In "New Plywood Boats" TF Jones gives the weight of 5mm okume marine plywood as 1/2 pound per square foot, which is the same weight as lauan underlayment which I think is 5.22mm. They may not be the same thickness but would be substituted for each other in small boats. In "Dingy Building" Richard Creagh-Osboren gives the following weights for boatbuiding timber, not plywood, but probalby close enough .. okume 25 lb/cu ft lauan 37 lb/cu ft meranti 25-45 lb/cu ft I thought meranti was a type of lauan but I was wrong. Like lauan, meranti seems to be a species of tree with different varieties used, two mentioned by Creagh-Osborne are Borneo red Sereya and Oba Suluk. Confusing for the boatbuilder. For comparison, douglas fir is 33 lb/cu ft the above weights are within a pound of what is listed in "Skene's Elements" for the one's given in Skene's. not all are there. -- ------------------------------------------------------------------------------ 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 |
"Nicholas B" wrote in message ... Meranti... Use it if you will. But remember that your boat is contributing to deforestation in Borneo. Your pleasure... will be at someone's cost. Nicholas Well, you have a few alternatives. Meranti is just another name of a high grade of Luan. At least luan is a fast growing family of species and is rapidly being planted all around SE Asia. Then there is Okoume which comes almost exclusively from Gabon. The Dutch, Israeli and Chinese logging operations there are opening up primeval forest to settlement and are only giving lip service to replanting. Mahogany is impossible to get any more. There is always spruce and fir but the Shrub is opening up our national forests to strip that out so that the oil companies can start drilling. That leaves Southern yellow pine which makes a very poor and heavy boat building wood. So if you want to be an ecco-boatbuilder it boils down to using a vastly inferior domestic pine plywood, a slightly better spruce and rip up our own National Forests, a good light boat in okoume and help destroy the forests in Gabon or use luan/meranti and let some SE Asians make an honest living planting and harvesting trees. |
Glenn Ashmore wrote:
"Nicholas B" wrote in message ... Meranti... Use it if you will. But remember that your boat is contributing to deforestation in Borneo. Your pleasure... will be at someone's cost. Nicholas Then there is Okoume which comes almost exclusively from Gabon. The Dutch, Israeli and Chinese logging operations there are opening up primeval forest to settlement and are only giving lip service to replanting. According to Shelman Marine, a major manufacturer of okoume plywood, nearly all of the okoume on the market comes from plantation grown trees. It seems that whatever old growth okoume there is on the market is a by product of development, not of deliberate logging. |
It's tough to be completely "green" and build a boat. The wood comes
from, hopefully, tree farms but there's always the risk it's from deforrestation. Resin, poly, vinyl, or epoxy, is a petroleum based product. Glues, nails, foam, fiberglass, etc, can all be linked back to some process that isn't environmentally friendly. Best one can do is buy their materials from companies that reduce the impact on the environment...or at least claim to. Bit of a leap of faith. Glenn Ashmore wrote: "Nicholas B" wrote in message ... Meranti... Use it if you will. But remember that your boat is contributing to deforestation in Borneo. Your pleasure... will be at someone's cost. Nicholas Well, you have a few alternatives. Meranti is just another name of a high grade of Luan. At least luan is a fast growing family of species and is rapidly being planted all around SE Asia. Then there is Okoume which comes almost exclusively from Gabon. The Dutch, Israeli and Chinese logging operations there are opening up primeval forest to settlement and are only giving lip service to replanting. Mahogany is impossible to get any more. There is always spruce and fir but the Shrub is opening up our national forests to strip that out so that the oil companies can start drilling. That leaves Southern yellow pine which makes a very poor and heavy boat building wood. So if you want to be an ecco-boatbuilder it boils down to using a vastly inferior domestic pine plywood, a slightly better spruce and rip up our own National Forests, a good light boat in okoume and help destroy the forests in Gabon or use luan/meranti and let some SE Asians make an honest living planting and harvesting trees. |
Matt Langenfeld ) writes: It's tough to be completely "green" and build a boat. The wood comes from, hopefully, tree farms but there's always the risk it's from deforrestation. I dont' think eastern white cedar is a problem. It's a bit of a weed species. Grows pretty fast. It's used here for fencing and backyard decks. People plant if as an evergreen hedge around their yards. -- ------------------------------------------------------------------------------ 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 |
From everything I can find plantations are almost insignificant in Gabon's
Okoume production. About 60% of Gabon's forests are under logging concessions. (12,000,000 hectares of a total 22,000,000) So far I can find data on only 12 plantations totaling about 800,000 hectares. The oldest of which is about 18 years old and just starting its first major harvest. Don't get me wrong. I am no tree hugger and intend to continue using my share of okoume where it is called for but it is always a good idea to know where your wood comes from and how it is effecting the local economy and ecosystem. "Brian Nystrom" wrote in message ... According to Shelman Marine, a major manufacturer of okoume plywood, nearly all of the okoume on the market comes from plantation grown trees. It seems that whatever old growth okoume there is on the market is a by product of development, not of deliberate logging. |
Northern White Cedar (Thuja Canadensis, I think) is available but it can
be difficult to find such wood that is high enough quality to plank a boat.(Unless you know where to look.) But there is plenty of it growing in Northern New England and Southern Quebec. I'd say it is one of the SLOWER growing softwoods. At least here. I'm not sure what Eastern White Cedar is. My USDA WOOD BOOK doesn't mention it. There is another type of cedar growing along the east coast generally called Atlantic white cedar. I think the latin name is Juniprus Virginiana. Both trees are often confused with Arbor Vitae, often used as an ornamental fence row. I have planted white cedar in rows around my place as a hedge though. Either woods makes great boat planking but are generally too soft for framing. These woods are not generally available at retail places like Home Despot. but there's always the risk it's from deforrestation. The white cedar I have access to is cut by people who are well aware of the dangers of over harvsting and seem to do a pretty good job of managing their logging operations with the long haul in mind. This is about the "greenest" place on earth politically and environmentally. (Green Mountains, Vermont) It may be hard for some who live in urban areas to believe that there are still areas left that have not been paved over. So I'd have to agree with William and would not feel guilty about using White cedar. Now,Mahogany....that's another story. bubinga and gaboon..well who knows? William R. Watt wrote: Matt Langenfeld ) writes: It's tough to be completely "green" and build a boat. The wood comes from, hopefully, tree farms but there's always the risk it's from deforrestation. I dont' think eastern white cedar is a problem. It's a bit of a weed species. Grows pretty fast. It's used here for fencing and backyard decks. People plant if as an evergreen hedge around their yards. -- ------------------------------------------------------------------------------ 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 |
We call it "Swamp Juniper" around the South. It grows in the wetlands of
North Carolina and South Georgia and tou are correct taht boat grade white cedar is hard to find. It is definitely not made into plywood. I had 3 loggers looking for good logs when I started Rutu. Finally found a prime log in Caro,GA and a second in Nags Head. "steveJ" wrote in message ... Northern White Cedar (Thuja Canadensis, I think) is available but it can be difficult to find such wood that is high enough quality to plank a boat.(Unless you know where to look.) But there is plenty of it growing in Northern New England and Southern Quebec. I'd say it is one of the SLOWER growing softwoods. At least here. I'm not sure what Eastern White Cedar is. My USDA WOOD BOOK doesn't mention it. There is another type of cedar growing along the east coast generally called Atlantic white cedar. I think the latin name is Juniprus Virginiana. Both trees are often confused with Arbor Vitae, often used as an ornamental fence row. I have planted white cedar in rows around my place as a hedge though. Either woods makes great boat planking but are generally too soft for framing. These woods are not generally available at retail places like Home Despot. but there's always the risk it's from deforrestation. The white cedar I have access to is cut by people who are well aware of the dangers of over harvsting and seem to do a pretty good job of managing their logging operations with the long haul in mind. This is about the "greenest" place on earth politically and environmentally. (Green Mountains, Vermont) It may be hard for some who live in urban areas to believe that there are still areas left that have not been paved over. So I'd have to agree with William and would not feel guilty about using White cedar. Now,Mahogany....that's another story. bubinga and gaboon..well who knows? William R. Watt wrote: Matt Langenfeld ) writes: It's tough to be completely "green" and build a boat. The wood comes from, hopefully, tree farms but there's always the risk it's from deforrestation. I dont' think eastern white cedar is a problem. It's a bit of a weed species. Grows pretty fast. It's used here for fencing and backyard decks. People plant if as an evergreen hedge around their yards. -- -------------------------------------------------------------------------- ---- 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 |
Matt Langenfeld wrote:
Best one can do is buy their materials from companies that reduce the impact on the environment... ....and build durable boats that will last for decades. |
Brian Nystrom ) writes: Matt Langenfeld wrote: Best one can do is buy their materials from companies that reduce the impact on the environment... ...and build durable boats that will last for decades. that's an enviable sentiment, unfortunately people's intitial enthusiasm over recreational boating usually doesn't last and the boats become neglected. the urban and rual shorelines where I paddle are littered with neglected dirty boats. in that respect a lot of wood that goes into recreational boats is wasted, no matter what the quality of material or construction. there should be a better way of utilizing scarce resources. I think the more money people have to spend on recreation, the more rare and expensive materials will be wasted. Perhaps those of us who build small and cheap using recyled materials are on a better environmental path. -- ------------------------------------------------------------------------------ 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 |
"Mike" wrote in message
... Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? The plans for the boat I'm building call for ACX. I now wish I used something else because I'm getting tired of filling the unfinished side. -Scott Roper |
Maybe someone out there knows what the trade name of this plywood is, but I
was recently talking to a guy restoring a 1953 sail boat and on the deck he was using the plywood that they use for the large billboard signs. It is made to withstand weather after all. Cheaper than marine plywood too. Says its not the first time he used it (not on the same boat either). "Mike" wrote in message ... Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? |
"sel1" writes: Maybe someone out there knows what the trade name of this plywood is, but I was recently talking to a guy restoring a 1953 sail boat and on the deck he was using the plywood that they use for the large billboard signs. MDO. Lew |
"Mike" writes: Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? If you are going to use it in the hull, marine ply is the only way to go since it has no voids and can be bent in a continuous curve which other plys will no properly do. If you are talking structural core material such as bulkheads, floors and sub soles, that's a different animal. I used 140 sheets of 1/2", 4 ply, CDX plywood sheathed with 50 oz of knitted glass and epoxy to build my boat. In my application, could give a hoot less about the voids since the ply was strictly core material, the glass carries the load. HTH Lew |
"Lew Hodgett" ) writes: In my application, could give a hoot less about the voids since the ply was strictly core material, the glass carries the load. the voids are where the rot begins. heat and moisture in those tiny air spaces. MDO plywood means "meduim density overlay". I read that it refers to a plastic coating. It was developed for highway signs, those big ones you see on the freeways, to be weather resistant. The main advantage is the nice smooth surface for interior walls, er, bulkheads. -- ------------------------------------------------------------------------------ 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 |
"William R. Watt" writes: the voids are where the rot begins. heat and moisture in those tiny air spaces. Since all exposed surfaces are sealed with epoxy before the glass was applied, chances of rot are slim and none. MDO plywood means "meduim density overlay". I read that it refers to a plastic coating. It was developed for highway signs, those big ones you see on the freeways, to be weather resistant. The main advantage is the nice smooth surface for interior walls, er, bulkheads. Actually it's a paper covering available on either one side or both sides, otherwise it standard exterior grade ply. Nice stuff for making wood working jigs, but IMHO, a total waste on a boat. Lew |
"William R. Watt" wrote: "Lew Hodgett" ) writes: In my application, could give a hoot less about the voids since the ply was strictly core material, the glass carries the load. the voids are where the rot begins. heat and moisture in those tiny air spaces. I've recently carved up 6 sheets of 1/2" MDO and didn't come across anything even resembling a void. Granted I didn't cut it into teeny pieces but many of them were relatively small enough that I would have expected to find a void were there any. Actually I like it, at least the stuff I've used. All plies are even thickness. MDO plywood means "meduim density overlay". I read that it refers to a plastic coating. The coating is paper and there are 2 versions of that I'm finding. The brown coating soaks upo epoxy like a sponge and I doubt it would itself be waterproof. The green coating seems to be already resin coated as epoxy will not penetrate it. It was developed for highway signs, those big ones you see on the freeways, to be weather resistant. The main advantage is the nice smooth surface for interior walls, er, bulkheads. I've used it for decks (glass covered) on power boats with no problems. Brian Cleverly -- ------------------------------------------------------------------------------ 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 |
Medium Density Overlaid Plywood can usually be special ordered from
any retail lumber yard. Georgia Pacific now makes most of it I think. I used to buy a brand called Roseburg and there were two grades, regular, and "2-step" which is smoother with less voids. The coating which is described as "resin impregneated fiber" looks like brownish paper. I've built boats out of it to save a buck and it works BUT....the quality of MDO seems to vary. Occasionally there are rather large voids in it. Generally the 3/8 inch thickness has no or very few voids and the 1/2 inch has more voids. The 3/4 inch is worthless. So if you want, say, a transom that is 3/4 inch thick,sandwich two thinner pieces together with epoxy. Also, MDO is available with the "paper coating" on either one or both sides...specified P1S or P2S. This plywood is generally high quality douglas fir, just like marine but with an occasional void. There is also an HDO plywood that is used for concrete form work. I have never used it but its worth a look if you have a source. The trouble with marine fir plywood is that it checks badly unless epoxy glass coated. In any case, I'd cover at least the outside with epoxy and glass when using MDO. sel1 wrote: Maybe someone out there knows what the trade name of this plywood is, but I was recently talking to a guy restoring a 1953 sail boat and on the deck he was using the plywood that they use for the large billboard signs. It is made to withstand weather after all. Cheaper than marine plywood too. Says its not the first time he used it (not on the same boat either). "Mike" wrote in message ... Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? |
steveJ ) writes: There is also an HDO plywood that is used for concrete form work. I have never used it but its worth a look if you have a source. I looked at some at a constrcution site. They were delivering full skids of it to use on a high rise condo. It was too thick and heavy looking lof light boats. I copied down the name stencilled on teh side of teh skid and looked it up on the Internet.There were no details about its compostiion or characteristics. i can't remember what it was called. In Asia they use a "plywood" made of bamboo for concrete forming. It is said to last longer than fir plywood. Apparently they use it many more times before they have to throw it out. It's made by weaving thin strips of the tough outer layer of the bamboo into veneers which are glued together in layers like plywood. I imagine that would leave an uneven surface which would be filled with resin like fibreglass cloth, making the "plywood" heavy. I looked up a supplier (Sino Forest) on the Internet. It doesn't seem to come in thin sheets. It would be interesting to get one's hand on a sample. Bamboo is a grass which growns very fast so it sounds like a more "ecologically sustainable" material. -- ------------------------------------------------------------------------------ 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 |
On Thu, 23 Sep 2004 22:38:04 GMT, "Mike"
vaguely proposed a theory .......and in reply I say!: remove ns from my header address to reply via email I post this because you have had many answers trying to help and in 6 days you have not bothered to reply. Just imagine! You're put there TROLLING one day, and you hit a reef. Suddenly you think "Did my message REALLY have enough irony in it to really satisfy me?" And as your pitiful question sinks under the foam of well-meaing replies, you SHOULD realise that really, the real thing is the only satisfying thing! Can you use any kind of plywood for boatbuilding ort does it have to be marine ply? Surely if you are planning on glassing and painting a plywood hull it wouldn't really matter? ************************************************** *** I know I am wrong about just about everything. So I am not going to listen when I am told I am wrong about the things I know I am right about. |
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Old Nick ) writes: On 30 Sep 2004 13:25:27 GMT, (William R. Watt) vaguely proposed a theory ......and in reply I say!: remove ns from my header address to reply via email Nothing is ecologically sustainable when humans get hold of it.... come to Ottawa and visit the Dominion Arbortetum :) -- ------------------------------------------------------------------------------ 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 |
"scott downey" wrote in message ...
I rebuilt my Flybridge from carefully selected exterior treated arsenic plywood both 1/2 and 3/4 inch. I sanded itsnip Better you than me... |
"John Cassara" ) writes: High quality materials ensure a long lasting quality product. High quality materials + high quality construction + high quality maintenance + high quality storage + high quality use but hey, you can get 4 out of the 5 with lower quality materials, and have boat that lasts almost as long for a lot less money. if you only provide the first of the 5 the boat won't last any longer and you still save money. :) -- ------------------------------------------------------------------------------ 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 |
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