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Thread: Marine plywood vs luan plywood

  1. #1
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    Apr 2001
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    Rimouski, Québec, Canada
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    At almost any local lumberyard you will find a plywood sold under the generic name "luan" for a stuningly moderate price (15.00$ canadian for a 1/4" sheet here in eastern Québec). It has only three ply, the outside faces being thin rotary cut philippine mahogany veneer glued on a thicker and lighter core, so its mechanical properties are at best mediocre. However one of its face is wihtout flaw, it is much lighter than a marine plywood of the same thickness and it will bend into fair curves. For building say, a hard chine kayak hull, I would suggest that such a plywood is perfectly appropriate if the hull is to be laminated with epoxy and fiberglass, that is most of the time. But I would like to be convinced otherwise.

  2. #2
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    Apr 2001
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    Rimouski, Québec, Canada
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    Default

    At almost any local lumberyard you will find a plywood sold under the generic name "luan" for a stuningly moderate price (15.00$ canadian for a 1/4" sheet here in eastern Québec). It has only three ply, the outside faces being thin rotary cut philippine mahogany veneer glued on a thicker and lighter core, so its mechanical properties are at best mediocre. However one of its face is wihtout flaw, it is much lighter than a marine plywood of the same thickness and it will bend into fair curves. For building say, a hard chine kayak hull, I would suggest that such a plywood is perfectly appropriate if the hull is to be laminated with epoxy and fiberglass, that is most of the time. But I would like to be convinced otherwise.

  3. #3
    Join Date
    Apr 2001
    Location
    Rimouski, Québec, Canada
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    Default

    At almost any local lumberyard you will find a plywood sold under the generic name "luan" for a stuningly moderate price (15.00$ canadian for a 1/4" sheet here in eastern Québec). It has only three ply, the outside faces being thin rotary cut philippine mahogany veneer glued on a thicker and lighter core, so its mechanical properties are at best mediocre. However one of its face is wihtout flaw, it is much lighter than a marine plywood of the same thickness and it will bend into fair curves. For building say, a hard chine kayak hull, I would suggest that such a plywood is perfectly appropriate if the hull is to be laminated with epoxy and fiberglass, that is most of the time. But I would like to be convinced otherwise.

  4. #4
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    Feb 2001
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    Grand Bay, New Brunswick, Canada
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    Luan is OK stuff.
    I built a small punt with Luan sheets and used cut up Luan door casing for chines, gunn'ls and rubbing strakes.
    %&#@*glass taped the seams only and coated all inside and out with WEST.
    I think that was 6 years ago, still holding up well. In fact i'm about to do another one.
    Are we Canadians cheap or just thrifty? -

  5. #5
    Join Date
    Feb 2001
    Location
    Grand Bay, New Brunswick, Canada
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    3

    Default

    Luan is OK stuff.
    I built a small punt with Luan sheets and used cut up Luan door casing for chines, gunn'ls and rubbing strakes.
    %&#@*glass taped the seams only and coated all inside and out with WEST.
    I think that was 6 years ago, still holding up well. In fact i'm about to do another one.
    Are we Canadians cheap or just thrifty? -

  6. #6
    Join Date
    Feb 2001
    Location
    Grand Bay, New Brunswick, Canada
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    3

    Default

    Luan is OK stuff.
    I built a small punt with Luan sheets and used cut up Luan door casing for chines, gunn'ls and rubbing strakes.
    %&#@*glass taped the seams only and coated all inside and out with WEST.
    I think that was 6 years ago, still holding up well. In fact i'm about to do another one.
    Are we Canadians cheap or just thrifty? -

  7. #7
    Join Date
    Aug 1999
    Location
    Belfast, ME
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    150

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    I built my kayak using luan, glassed both sides. It is very durable.

  8. #8
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    Aug 1999
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    Belfast, ME
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    I built my kayak using luan, glassed both sides. It is very durable.

  9. #9
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    I built my kayak using luan, glassed both sides. It is very durable.

  10. #10
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    Nov 2000
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    Loudoun County, VA
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    It's okay stuff, not very durable so just coat w/ epoxy or better yet glass/epoxy. The big difference is as you stated: 1/4" but only 3 ply. Good 6mm (1/4") stuff is 5 ply which is better at bending and not developing hard spots. But hey, if you don't have a complex hull shape or no tight bends. . . Good find!!!!

  11. #11
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    It's okay stuff, not very durable so just coat w/ epoxy or better yet glass/epoxy. The big difference is as you stated: 1/4" but only 3 ply. Good 6mm (1/4") stuff is 5 ply which is better at bending and not developing hard spots. But hey, if you don't have a complex hull shape or no tight bends. . . Good find!!!!

  12. #12
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    It's okay stuff, not very durable so just coat w/ epoxy or better yet glass/epoxy. The big difference is as you stated: 1/4" but only 3 ply. Good 6mm (1/4") stuff is 5 ply which is better at bending and not developing hard spots. But hey, if you don't have a complex hull shape or no tight bends. . . Good find!!!!

  13. #13
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    I also built an 8ft punt out of the stuff. Since it is encapsulated in epoxy (and the bottom has glass as well), it worked fine, though there has been slight discolouration under the coating. Three seasons of hard use.

    I would use it for a throw-away boat only, one you'll build very simply and cover with epoxy and paint. If you're going to go to the trouble of varnish, the labour intensifies, and you might as well make it of better material.

    The light weight of Lauan is very nice though.

  14. #14
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    I also built an 8ft punt out of the stuff. Since it is encapsulated in epoxy (and the bottom has glass as well), it worked fine, though there has been slight discolouration under the coating. Three seasons of hard use.

    I would use it for a throw-away boat only, one you'll build very simply and cover with epoxy and paint. If you're going to go to the trouble of varnish, the labour intensifies, and you might as well make it of better material.

    The light weight of Lauan is very nice though.

  15. #15
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    I also built an 8ft punt out of the stuff. Since it is encapsulated in epoxy (and the bottom has glass as well), it worked fine, though there has been slight discolouration under the coating. Three seasons of hard use.

    I would use it for a throw-away boat only, one you'll build very simply and cover with epoxy and paint. If you're going to go to the trouble of varnish, the labour intensifies, and you might as well make it of better material.

    The light weight of Lauan is very nice though.

  16. #16
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    Chesapeake Beach, Md 20732 U.S.A.
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    I have made this statement elsewhere in this forum...Philippine Mahogany is not a true mahogany but a tropical cedar. It will discolor in sunlight, it will generally turn urine yellow when exposed. If you want to finish it bright it must be stained, although the stain is not permanent....epoxy coat and paint. It takes paint well.

  17. #17
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    I have made this statement elsewhere in this forum...Philippine Mahogany is not a true mahogany but a tropical cedar. It will discolor in sunlight, it will generally turn urine yellow when exposed. If you want to finish it bright it must be stained, although the stain is not permanent....epoxy coat and paint. It takes paint well.

  18. #18
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    I have made this statement elsewhere in this forum...Philippine Mahogany is not a true mahogany but a tropical cedar. It will discolor in sunlight, it will generally turn urine yellow when exposed. If you want to finish it bright it must be stained, although the stain is not permanent....epoxy coat and paint. It takes paint well.

  19. #19
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    Sep 1999
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    Muncy, PA, USA
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    Luan is HIGHLY variable. I bought some for patterns last fall and it was fabulous; totally clear and smooth both sides with thick outer plys. No voids that I found. I did not subject it to the dishwasher test because I doubt I'll find as nice again soon. Rick

  20. #20
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    Sep 1999
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    Luan is HIGHLY variable. I bought some for patterns last fall and it was fabulous; totally clear and smooth both sides with thick outer plys. No voids that I found. I did not subject it to the dishwasher test because I doubt I'll find as nice again soon. Rick

  21. #21
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    Sep 1999
    Location
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    Luan is HIGHLY variable. I bought some for patterns last fall and it was fabulous; totally clear and smooth both sides with thick outer plys. No voids that I found. I did not subject it to the dishwasher test because I doubt I'll find as nice again soon. Rick

  22. #22
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    Feb 2000
    Location
    Wisconsin--Lake Michigan, where the water tastes funny
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    Years ago a group of us built a dozen El Toro dinghies for frostbiting. I had specified Bruynzeel 1/4" plywood but the group opted for lauan--Philippine-faced softwood. The fleet began to fall apart from delimination in about the fifth year. However, that was before epoxy coating came along. Lauan is nice and light, so the additional weight of epoxy or even epoxy-fibreglas (oops, sorry: f$#&*@!s) might not make a small dinghy overweight.
    What does anyone think of using lauan for glued plywood lapstrake construction of, say, a fifteen foot Whitehall type? What thickness? I wouldn't use cloth, but how about coating with epoxy before hanging the plank? My present thinking is to use the best plywood available, in view of the time and cost to build such a boat, but I'm open to suggestion.

  23. #23
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    Feb 2000
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    Wisconsin--Lake Michigan, where the water tastes funny
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    Years ago a group of us built a dozen El Toro dinghies for frostbiting. I had specified Bruynzeel 1/4" plywood but the group opted for lauan--Philippine-faced softwood. The fleet began to fall apart from delimination in about the fifth year. However, that was before epoxy coating came along. Lauan is nice and light, so the additional weight of epoxy or even epoxy-fibreglas (oops, sorry: f$#&*@!s) might not make a small dinghy overweight.
    What does anyone think of using lauan for glued plywood lapstrake construction of, say, a fifteen foot Whitehall type? What thickness? I wouldn't use cloth, but how about coating with epoxy before hanging the plank? My present thinking is to use the best plywood available, in view of the time and cost to build such a boat, but I'm open to suggestion.

  24. #24
    Join Date
    Feb 2000
    Location
    Wisconsin--Lake Michigan, where the water tastes funny
    Posts
    1,080

    Default

    Years ago a group of us built a dozen El Toro dinghies for frostbiting. I had specified Bruynzeel 1/4" plywood but the group opted for lauan--Philippine-faced softwood. The fleet began to fall apart from delimination in about the fifth year. However, that was before epoxy coating came along. Lauan is nice and light, so the additional weight of epoxy or even epoxy-fibreglas (oops, sorry: f$#&*@!s) might not make a small dinghy overweight.
    What does anyone think of using lauan for glued plywood lapstrake construction of, say, a fifteen foot Whitehall type? What thickness? I wouldn't use cloth, but how about coating with epoxy before hanging the plank? My present thinking is to use the best plywood available, in view of the time and cost to build such a boat, but I'm open to suggestion.

  25. #25
    Join Date
    Jul 1999
    Location
    USA
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    BayBoat,

    I am about 6 months into building a 13' 6" glued lapstrake boat. I work on it about 10 to 15 hours a week and just finished the planking. Considering my investment in time, I wouldn't want to use luan. I did use what the local home center called 1/4" luan (some of the poorest quality plywood you would ever hope to run across)for the strake patterns and it seemed to take the bending and twisting OK.

  26. #26
    Join Date
    Jul 1999
    Location
    USA
    Posts
    543

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    BayBoat,

    I am about 6 months into building a 13' 6" glued lapstrake boat. I work on it about 10 to 15 hours a week and just finished the planking. Considering my investment in time, I wouldn't want to use luan. I did use what the local home center called 1/4" luan (some of the poorest quality plywood you would ever hope to run across)for the strake patterns and it seemed to take the bending and twisting OK.

  27. #27
    Join Date
    Jul 1999
    Location
    USA
    Posts
    543

    Default

    BayBoat,

    I am about 6 months into building a 13' 6" glued lapstrake boat. I work on it about 10 to 15 hours a week and just finished the planking. Considering my investment in time, I wouldn't want to use luan. I did use what the local home center called 1/4" luan (some of the poorest quality plywood you would ever hope to run across)for the strake patterns and it seemed to take the bending and twisting OK.

  28. #28
    Join Date
    Oct 2000
    Location
    Boonville, MO
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    I used 1/4" Luan for the interior paneling on my 39 foot houseboat, it has a nice smooth surface for painting, unlike Fir. None of the Luan was used for critical structural stuff, though. The stuff I got had a thick inner core, and very thin outer cores. It was sold as "underlayment".

  29. #29
    Join Date
    Oct 2000
    Location
    Boonville, MO
    Posts
    959

    Default

    I used 1/4" Luan for the interior paneling on my 39 foot houseboat, it has a nice smooth surface for painting, unlike Fir. None of the Luan was used for critical structural stuff, though. The stuff I got had a thick inner core, and very thin outer cores. It was sold as "underlayment".

  30. #30
    Join Date
    Oct 2000
    Location
    Boonville, MO
    Posts
    959

    Default

    I used 1/4" Luan for the interior paneling on my 39 foot houseboat, it has a nice smooth surface for painting, unlike Fir. None of the Luan was used for critical structural stuff, though. The stuff I got had a thick inner core, and very thin outer cores. It was sold as "underlayment".

  31. #31
    Join Date
    Apr 2000
    Location
    Southampton Ont. Canada
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    Anyone who wants to build a boat out of 1/4" luaun underlay should look at the delaminating disappointment in my yard.
    On the other hand, the kayak that I built from 1/8" and skinned with 4oz. glass,is still going strong.
    Have fun
    R

  32. #32
    Join Date
    Apr 2000
    Location
    Southampton Ont. Canada
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    Anyone who wants to build a boat out of 1/4" luaun underlay should look at the delaminating disappointment in my yard.
    On the other hand, the kayak that I built from 1/8" and skinned with 4oz. glass,is still going strong.
    Have fun
    R

  33. #33
    Join Date
    Apr 2000
    Location
    Southampton Ont. Canada
    Posts
    5,567

    Default

    Anyone who wants to build a boat out of 1/4" luaun underlay should look at the delaminating disappointment in my yard.
    On the other hand, the kayak that I built from 1/8" and skinned with 4oz. glass,is still going strong.
    Have fun
    R

  34. #34
    Join Date
    Feb 2000
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    Omaha, Nebraska, USA, Terra , Sol, Milky Way....
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    Not all luan is created equal....

    We all know that, right?

    --Norm

  35. #35
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    Not all luan is created equal....

    We all know that, right?

    --Norm

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