Western red cedar marine plywood

[John A. Campbell]

Does anyone know of a source for western red cedar marine plywood in a 1/4" thickness in 4' X 8' sheets? Has anyone ever bonded (with epoxy) 1/8" western red cedar veneer to 3 mm occume marine plywood and used this for planking stock in glued lap construction? I plan to build Woodenboat's "Piccolo" and prefer to use glued lap construction but I want a western red cedar outer surface. I know some of you have used a similiar technique for decks but so far I have not seen a thread where this was used for lapstrake planking. Comments?

[John A. Campbell]

Does anyone know of a source for western red cedar marine plywood in a 1/4" thickness in 4' X 8' sheets? Has anyone ever bonded (with epoxy) 1/8" western red cedar veneer to 3 mm occume marine plywood and used this for planking stock in glued lap construction? I plan to build Woodenboat's "Piccolo" and prefer to use glued lap construction but I want a western red cedar outer surface. I know some of you have used a similiar technique for decks but so far I have not seen a thread where this was used for lapstrake planking. Comments?

[John A. Campbell]

Does anyone know of a source for western red cedar marine plywood in a 1/4" thickness in 4' X 8' sheets? Has anyone ever bonded (with epoxy) 1/8" western red cedar veneer to 3 mm occume marine plywood and used this for planking stock in glued lap construction? I plan to build Woodenboat's "Piccolo" and prefer to use glued lap construction but I want a western red cedar outer surface. I know some of you have used a similiar technique for decks but so far I have not seen a thread where this was used for lapstrake planking. Comments?

[JimD]

Not quite an answer to your question, but I used cheaper mahogany plywood for deck, cabin, combing, and fiberglassed it. Didn't like the look of it (too plywoodish) so epoxied red cedar strip over all of it. For the strips I just took cedar 2 x 4s and ran 'em through the table saw. Turned out very well.
jim

[JimD]

Not quite an answer to your question, but I used cheaper mahogany plywood for deck, cabin, combing, and fiberglassed it. Didn't like the look of it (too plywoodish) so epoxied red cedar strip over all of it. For the strips I just took cedar 2 x 4s and ran 'em through the table saw. Turned out very well.
jim

[JimD]

Not quite an answer to your question, but I used cheaper mahogany plywood for deck, cabin, combing, and fiberglassed it. Didn't like the look of it (too plywoodish) so epoxied red cedar strip over all of it. For the strips I just took cedar 2 x 4s and ran 'em through the table saw. Turned out very well.
jim

[Bruce Taylor]

Hi John -- I've never heard of marine ply w/ western red cedar face veneers. I've seen 1/4" ply w/ aromatic (pencil) cedar facing, but the samples I've seen have been shoddy stuff, meant for drawer bottoms and closet linings. It probably would not meet yr. need.

As for gluing cedar veneers to an okoume substrate, I can't offer an informed opinion, since I've never tried it (you might want to post a question on the subject in Building & Repair, where there's a lot more traffic). I would want to hear some pretty credible testimony that cedar veneers behave themselves when glued to an immovable substrate that is frequently immersed. It would be a shame if you built this intricate boat and then had problems with checking, cupping, or wrinkling.

[Bruce Taylor]

Hi John -- I've never heard of marine ply w/ western red cedar face veneers. I've seen 1/4" ply w/ aromatic (pencil) cedar facing, but the samples I've seen have been shoddy stuff, meant for drawer bottoms and closet linings. It probably would not meet yr. need.

As for gluing cedar veneers to an okoume substrate, I can't offer an informed opinion, since I've never tried it (you might want to post a question on the subject in Building & Repair, where there's a lot more traffic). I would want to hear some pretty credible testimony that cedar veneers behave themselves when glued to an immovable substrate that is frequently immersed. It would be a shame if you built this intricate boat and then had problems with checking, cupping, or wrinkling.

[Bruce Taylor]

Hi John -- I've never heard of marine ply w/ western red cedar face veneers. I've seen 1/4" ply w/ aromatic (pencil) cedar facing, but the samples I've seen have been shoddy stuff, meant for drawer bottoms and closet linings. It probably would not meet yr. need.

As for gluing cedar veneers to an okoume substrate, I can't offer an informed opinion, since I've never tried it (you might want to post a question on the subject in Building & Repair, where there's a lot more traffic). I would want to hear some pretty credible testimony that cedar veneers behave themselves when glued to an immovable substrate that is frequently immersed. It would be a shame if you built this intricate boat and then had problems with checking, cupping, or wrinkling.

[Ross Faneuf]

My hatch slides are okume ply with mahogany veneer (1/16") on both sides. After 3 seasons they're still, well, perfect - no warping or anything else. I suppose that cedar veneer would behave just as well, as both woods have excellent gluing/laminating properties.

[Ross Faneuf]

My hatch slides are okume ply with mahogany veneer (1/16") on both sides. After 3 seasons they're still, well, perfect - no warping or anything else. I suppose that cedar veneer would behave just as well, as both woods have excellent gluing/laminating properties.

[Ross Faneuf]

My hatch slides are okume ply with mahogany veneer (1/16") on both sides. After 3 seasons they're still, well, perfect - no warping or anything else. I suppose that cedar veneer would behave just as well, as both woods have excellent gluing/laminating properties.

[John A. Campbell]

I discussed the lamination of 3 mm occume to 1/8" western red cedar veneer with Gougeon Brothers, M. L. Condon Lumber Co., and with Bob Pickett of Flounder Bay Lumber Co. All seemed to think this was a workable solution to the goal of glued lap planking with cedar as an outer surface. This next week I plan to resaw some clear W. R. cedar to 1/8" thickness and bond it to some leftover 3 mm Occume and actually do some sample glued laps with it after first coating the samples with varnish in a similiar manner as I would do a complete boat. These "samples" will be around 5 feet long. Then I'll expose these pieces to 3 - 4 hours of soaking after which they'll lay out on my shop deck in this nice hot Texas sunshine. I plan to do this daily for 30 days. Bob Pickett suggested boiling some of them and laying them out in the sun.....will do that too. Will post the results in about a month.......really have my heart set on a cedar Piccolo with glued lap construction.....hang the expense and time required to do it....!!

[John A. Campbell]

I discussed the lamination of 3 mm occume to 1/8" western red cedar veneer with Gougeon Brothers, M. L. Condon Lumber Co., and with Bob Pickett of Flounder Bay Lumber Co. All seemed to think this was a workable solution to the goal of glued lap planking with cedar as an outer surface. This next week I plan to resaw some clear W. R. cedar to 1/8" thickness and bond it to some leftover 3 mm Occume and actually do some sample glued laps with it after first coating the samples with varnish in a similiar manner as I would do a complete boat. These "samples" will be around 5 feet long. Then I'll expose these pieces to 3 - 4 hours of soaking after which they'll lay out on my shop deck in this nice hot Texas sunshine. I plan to do this daily for 30 days. Bob Pickett suggested boiling some of them and laying them out in the sun.....will do that too. Will post the results in about a month.......really have my heart set on a cedar Piccolo with glued lap construction.....hang the expense and time required to do it....!!

[John A. Campbell]

I discussed the lamination of 3 mm occume to 1/8" western red cedar veneer with Gougeon Brothers, M. L. Condon Lumber Co., and with Bob Pickett of Flounder Bay Lumber Co. All seemed to think this was a workable solution to the goal of glued lap planking with cedar as an outer surface. This next week I plan to resaw some clear W. R. cedar to 1/8" thickness and bond it to some leftover 3 mm Occume and actually do some sample glued laps with it after first coating the samples with varnish in a similiar manner as I would do a complete boat. These "samples" will be around 5 feet long. Then I'll expose these pieces to 3 - 4 hours of soaking after which they'll lay out on my shop deck in this nice hot Texas sunshine. I plan to do this daily for 30 days. Bob Pickett suggested boiling some of them and laying them out in the sun.....will do that too. Will post the results in about a month.......really have my heart set on a cedar Piccolo with glued lap construction.....hang the expense and time required to do it....!!

[Todd Bradshaw]

I think it's a neat idea. When you're testing the laminated stuff, don't forget to make sure that it will still bend and twist enough to do the job. It may turn out surprisingly stiff.

[Todd Bradshaw]

I think it's a neat idea. When you're testing the laminated stuff, don't forget to make sure that it will still bend and twist enough to do the job. It may turn out surprisingly stiff.

[Todd Bradshaw]

I think it's a neat idea. When you're testing the laminated stuff, don't forget to make sure that it will still bend and twist enough to do the job. It may turn out surprisingly stiff.

[John A. Campbell]

I think you're correct, Todd, about the stiffness of the laminate. I did some laminations last night with 4 mm Occume to 1/16" western red cedar (didn't have any 3 mm Occume) with w.r. bonded to 1 side of a sample and w. r. bonded to both sides of another sample. This morning I checked them and I believe they are indeed considerably stiffer than expected. Gougeon Bros. claims that two equal thicknesses bonded together are no stiffer than a single thickness twice as thick as the two separate ones but I don't agree with that. I plan to experiment a little with some 1.5 mm Occume (from Boulter Plywood Corp.) bonded to 3/32" w.r. cedar , with the cedar on one side and another sample with cedar on both sides. Also, I plan to document the various weights encountered with this little experiment. I'm giving each sample of laminate an epoxy coating on both sides of the bonded surface....takes 20 cc of epoxy "mix" per glue line per square foot. Gougeon Bros. claims that laminating with clamps results in 12.8 square feet per pound of epoxy per glue line and I'm sure this takes into account coating both sides of the bond. Also, I'm giving each sample 5 coats of Epifanes varnish, both sides and edges, sanded lightly between coats.

Yesterday, while resawing the western red on my trusty Delta 14-inch bandsaw (w/riser), I sliced out a piece 1/4" thick just to see how it would feel. This is the thickness called for in the plans for Piccolo's planking. The piece was 24" long X 7 1/4" wide.....a mild attempt to put a slight twist in this sample immediately resulted in a split of about 4" length so, needless to say, I won't be using 1/4" "pure" western red cedar in this boat in the traditional planking fashion. I'm convinced the western red needs a plywood "mate" in cases where the overall thickness is specified as 1/4". The question now is how to get the best flexibility....thicker cedar with thinner plywood or just the opposite.....or should both materials ideally be the same thickness. I'll be talking to Boulter Plywood about this....they sell the 1.5 mm Occume and have a resawing service that may be able to furnish the w. r. cedar veneer of required size. More later.....

[John A. Campbell]

I think you're correct, Todd, about the stiffness of the laminate. I did some laminations last night with 4 mm Occume to 1/16" western red cedar (didn't have any 3 mm Occume) with w.r. bonded to 1 side of a sample and w. r. bonded to both sides of another sample. This morning I checked them and I believe they are indeed considerably stiffer than expected. Gougeon Bros. claims that two equal thicknesses bonded together are no stiffer than a single thickness twice as thick as the two separate ones but I don't agree with that. I plan to experiment a little with some 1.5 mm Occume (from Boulter Plywood Corp.) bonded to 3/32" w.r. cedar , with the cedar on one side and another sample with cedar on both sides. Also, I plan to document the various weights encountered with this little experiment. I'm giving each sample of laminate an epoxy coating on both sides of the bonded surface....takes 20 cc of epoxy "mix" per glue line per square foot. Gougeon Bros. claims that laminating with clamps results in 12.8 square feet per pound of epoxy per glue line and I'm sure this takes into account coating both sides of the bond. Also, I'm giving each sample 5 coats of Epifanes varnish, both sides and edges, sanded lightly between coats.

Yesterday, while resawing the western red on my trusty Delta 14-inch bandsaw (w/riser), I sliced out a piece 1/4" thick just to see how it would feel. This is the thickness called for in the plans for Piccolo's planking. The piece was 24" long X 7 1/4" wide.....a mild attempt to put a slight twist in this sample immediately resulted in a split of about 4" length so, needless to say, I won't be using 1/4" "pure" western red cedar in this boat in the traditional planking fashion. I'm convinced the western red needs a plywood "mate" in cases where the overall thickness is specified as 1/4". The question now is how to get the best flexibility....thicker cedar with thinner plywood or just the opposite.....or should both materials ideally be the same thickness. I'll be talking to Boulter Plywood about this....they sell the 1.5 mm Occume and have a resawing service that may be able to furnish the w. r. cedar veneer of required size. More later.....

[John A. Campbell]

I think you're correct, Todd, about the stiffness of the laminate. I did some laminations last night with 4 mm Occume to 1/16" western red cedar (didn't have any 3 mm Occume) with w.r. bonded to 1 side of a sample and w. r. bonded to both sides of another sample. This morning I checked them and I believe they are indeed considerably stiffer than expected. Gougeon Bros. claims that two equal thicknesses bonded together are no stiffer than a single thickness twice as thick as the two separate ones but I don't agree with that. I plan to experiment a little with some 1.5 mm Occume (from Boulter Plywood Corp.) bonded to 3/32" w.r. cedar , with the cedar on one side and another sample with cedar on both sides. Also, I plan to document the various weights encountered with this little experiment. I'm giving each sample of laminate an epoxy coating on both sides of the bonded surface....takes 20 cc of epoxy "mix" per glue line per square foot. Gougeon Bros. claims that laminating with clamps results in 12.8 square feet per pound of epoxy per glue line and I'm sure this takes into account coating both sides of the bond. Also, I'm giving each sample 5 coats of Epifanes varnish, both sides and edges, sanded lightly between coats.

Yesterday, while resawing the western red on my trusty Delta 14-inch bandsaw (w/riser), I sliced out a piece 1/4" thick just to see how it would feel. This is the thickness called for in the plans for Piccolo's planking. The piece was 24" long X 7 1/4" wide.....a mild attempt to put a slight twist in this sample immediately resulted in a split of about 4" length so, needless to say, I won't be using 1/4" "pure" western red cedar in this boat in the traditional planking fashion. I'm convinced the western red needs a plywood "mate" in cases where the overall thickness is specified as 1/4". The question now is how to get the best flexibility....thicker cedar with thinner plywood or just the opposite.....or should both materials ideally be the same thickness. I'll be talking to Boulter Plywood about this....they sell the 1.5 mm Occume and have a resawing service that may be able to furnish the w. r. cedar veneer of required size. More later.....

[John A. Campbell]

I had previously mentioned experimenting with a lamination of western red cedar veneer to okoume plywood and the following are results so far:

I bonded (with West System epoxy) 1/16" w.r.c to both sides of a 6" X 24" piece of 4 mm Okoume.....did 2 samples of this. Also bonded 1/16" w.r.c. to one side of 6" X 24" piece of 4 mm Okoume ......2 samples of this. I then gave each sample piece 4 coats of Epifanes and added 2 additional pieces (6" X 24") of Okoume to the "test batch" and coated them with 4 coats of Epifanes. I soaked the "batch" in fresh water every night for 2 weeks and left them out in the Texas sun during the day for the same 2 weeks. At this time, the pieces with w.r.c. bonded to one side have both warped 1/8" across the grain (measured edge to edge) and 3/16" with the grain (measured end to end) . In the "cross grain warp", the plywood is on the convex side whereas the cedar is on the convex side " with the grain". The other 4 samples are still arrow straight so at this point, it looks like it will be necessary to laminate w.r.c. to BOTH sides of Piccolo's Okoume planking stock. . It is noted that the cedar samples are clear and flat sawn material. I have not yet tried to laminate to the 1.5 mm and 3 mm Okoume but plan to do so soon and am thinking of using vertical grain cedar for that test. Bob Pickett of Flounder Bay Lumber Co. had recommended vertical grain and somewhere I've read that vertical grain cedar is more flexible than flat sawn. I certainly hope so as the test pieces I've done so far have definitely become more stiff than I expected. Would appreciate any questions, comments, etc.

[John A. Campbell]

I had previously mentioned experimenting with a lamination of western red cedar veneer to okoume plywood and the following are results so far:

I bonded (with West System epoxy) 1/16" w.r.c to both sides of a 6" X 24" piece of 4 mm Okoume.....did 2 samples of this. Also bonded 1/16" w.r.c. to one side of 6" X 24" piece of 4 mm Okoume ......2 samples of this. I then gave each sample piece 4 coats of Epifanes and added 2 additional pieces (6" X 24") of Okoume to the "test batch" and coated them with 4 coats of Epifanes. I soaked the "batch" in fresh water every night for 2 weeks and left them out in the Texas sun during the day for the same 2 weeks. At this time, the pieces with w.r.c. bonded to one side have both warped 1/8" across the grain (measured edge to edge) and 3/16" with the grain (measured end to end) . In the "cross grain warp", the plywood is on the convex side whereas the cedar is on the convex side " with the grain". The other 4 samples are still arrow straight so at this point, it looks like it will be necessary to laminate w.r.c. to BOTH sides of Piccolo's Okoume planking stock. . It is noted that the cedar samples are clear and flat sawn material. I have not yet tried to laminate to the 1.5 mm and 3 mm Okoume but plan to do so soon and am thinking of using vertical grain cedar for that test. Bob Pickett of Flounder Bay Lumber Co. had recommended vertical grain and somewhere I've read that vertical grain cedar is more flexible than flat sawn. I certainly hope so as the test pieces I've done so far have definitely become more stiff than I expected. Would appreciate any questions, comments, etc.

[John A. Campbell]

I had previously mentioned experimenting with a lamination of western red cedar veneer to okoume plywood and the following are results so far:

I bonded (with West System epoxy) 1/16" w.r.c to both sides of a 6" X 24" piece of 4 mm Okoume.....did 2 samples of this. Also bonded 1/16" w.r.c. to one side of 6" X 24" piece of 4 mm Okoume ......2 samples of this. I then gave each sample piece 4 coats of Epifanes and added 2 additional pieces (6" X 24") of Okoume to the "test batch" and coated them with 4 coats of Epifanes. I soaked the "batch" in fresh water every night for 2 weeks and left them out in the Texas sun during the day for the same 2 weeks. At this time, the pieces with w.r.c. bonded to one side have both warped 1/8" across the grain (measured edge to edge) and 3/16" with the grain (measured end to end) . In the "cross grain warp", the plywood is on the convex side whereas the cedar is on the convex side " with the grain". The other 4 samples are still arrow straight so at this point, it looks like it will be necessary to laminate w.r.c. to BOTH sides of Piccolo's Okoume planking stock. . It is noted that the cedar samples are clear and flat sawn material. I have not yet tried to laminate to the 1.5 mm and 3 mm Okoume but plan to do so soon and am thinking of using vertical grain cedar for that test. Bob Pickett of Flounder Bay Lumber Co. had recommended vertical grain and somewhere I've read that vertical grain cedar is more flexible than flat sawn. I certainly hope so as the test pieces I've done so far have definitely become more stiff than I expected. Would appreciate any questions, comments, etc.

[Don Maurer]

Plywood stiffness increases as the cube of the thicknes. Therefore if you laminated a 1/16" veneer to each side of 4mm plywood, it should, in theory, be a little over 5 times stiffer.

[ 09-03-2002, 06:13 PM: Message edited by: Don Maurer ]

[Don Maurer]

Plywood stiffness increases as the cube of the thicknes. Therefore if you laminated a 1/16" veneer to each side of 4mm plywood, it should, in theory, be a little over 5 times stiffer.

[ 09-03-2002, 06:13 PM: Message edited by: Don Maurer ]

[Don Maurer]

Plywood stiffness increases as the cube of the thicknes. Therefore if you laminated a 1/16" veneer to each side of 4mm plywood, it should, in theory, be a little over 5 times stiffer.

[ 09-03-2002, 06:13 PM: Message edited by: Don Maurer ]

[John A. Campbell]

Thanks for the info, Don. I'll be trying the 1/16" wrc veneer bonded to both sides of a piece of 1.5 mm Okoume real soon. Hopefully it won't be any stiffer than, for example, a comparable size piece of "regular" 6 mm Okoume. I suspect the West epoxy itself adds to the stiffness.....no real solid info on this yet. With the 1.5 mm Okoume, my concern here is......will the plywood impart enough strength....read "control".......to stabilize the western red cedar? As Bruce Taylor has pointed out, Piccolo is a pretty substantial construction project without all this western red cedar added to it and I know of no other way to prove that this will work other than these steps I'm taking. Any thoughts?

[John A. Campbell]

Thanks for the info, Don. I'll be trying the 1/16" wrc veneer bonded to both sides of a piece of 1.5 mm Okoume real soon. Hopefully it won't be any stiffer than, for example, a comparable size piece of "regular" 6 mm Okoume. I suspect the West epoxy itself adds to the stiffness.....no real solid info on this yet. With the 1.5 mm Okoume, my concern here is......will the plywood impart enough strength....read "control".......to stabilize the western red cedar? As Bruce Taylor has pointed out, Piccolo is a pretty substantial construction project without all this western red cedar added to it and I know of no other way to prove that this will work other than these steps I'm taking. Any thoughts?

[John A. Campbell]

Thanks for the info, Don. I'll be trying the 1/16" wrc veneer bonded to both sides of a piece of 1.5 mm Okoume real soon. Hopefully it won't be any stiffer than, for example, a comparable size piece of "regular" 6 mm Okoume. I suspect the West epoxy itself adds to the stiffness.....no real solid info on this yet. With the 1.5 mm Okoume, my concern here is......will the plywood impart enough strength....read "control".......to stabilize the western red cedar? As Bruce Taylor has pointed out, Piccolo is a pretty substantial construction project without all this western red cedar added to it and I know of no other way to prove that this will work other than these steps I'm taking. Any thoughts?