DaveH6
Foredeck insulation
The blue styrofoam was 13/16 " thick thus too tall to fit between my laminated ribs which were slightly less than 3/4" thick. I used my surface planer to knock down the thickness of the insulation so it stood slightly proud between the ribs. Though the foam seemed easy to plane, I'm not sure how well the planer blades tolerated the foam's components.
I used a table saw to cut the foam into 3 5/8' strips to fit between the ribs. I used spacers when installing the ribs thus my care was rewarded as the foam strips fit without having to fuss with their widths. Some excitement in cutting the foam when the just cut strip was very succeptable to kick back if not controlled properly. Though a feather weight foam strip being expelled from the table saw posed little danger, it instinctly scared the dickens out of me as I ducked for cover.
The foam dust apparently had a static charge on it as the stuff stuck to vertical sufaces. Yup, I wore a respirator but looked like I had a blue snow cone on top of my head.
Before installing the foam, I coated the foredeck interior surfaces with epoxy to provide some moisture protection to the 4mm bottom panels and laminated ribs. I installed the foam into the wet epoxy, put some boards down on the foam and provided weight via limestone blocks. The cured epoxy held the foam tightly, at least in the short term.
Using a long board with 40 grit paper I leveled the foam with the tops of the ribs. The foam gives one a useful perspective of rib height and I found one rib that was standing proud probably from a wood scrap under it when epoxied in place. Epoxy was applied to the underside of the 6mm top plywood panels for moisture protection and perhaps some adherence to the foam thus meeting a requirement of "sandwich" construction in that the core is attached to both skins. Since the foredeck has ribs running throughout it thus a torsion box, it is academic whether the core is firmly attached to the inner and outer skins but it is always fun to find something else to postulate over.
The second of the two 1" wide ribs at the mid length location of the foredeck was necessary to correct an error I made in locating a rib (in relationship to the rib for the butt joint) at the point that the foredeck rests on the mahogany beam. Before correcting this error, I couldn't space the 1" wide ribs consistently to provide the mounting points for the decorative maghogany strips that will be installed on the interior of the foredeck. When I butt up the 6mm top panels, I will use the second rib for the mounting point thus make me feel that my measuring error provided a real or imagined strength benefit as the butt joints are now staggered over two ribs. However, the seam for the butt joint will now need to be glassed and faired. More weight and work as a consequence of my error. Perhaps I should just cover the bottom sheet's butt joint with the prescribed mahogany strip and live with a modest spacing error between two strips. Not sure if this paragraph makes sense but I lack the ability to explain it clearer.
In conclusion, the rib and decorative covering mahogany strip occurring at the plywood butt joint are the center of the universe when laying out the ribs . I got fixated on the rib occurring at the 1 3/4" wide main mahogany beam which led to getting the 1" rib locations out of sorts in regards to a dead on spacing between the decorative mahogany strips.
Though the plans prescribed 3" wide laminated plywood for the landing spot for the windshield, I made them 4' wide to give me wiggle room in response to my proclivity for foredeck measurement errors. Once the windshield is located, I can trim back back any excess on the port side plywood. Tom's plans specify how much the outer windshield frames sweep back from the center window thus how to position the port and starboard windshield landing spots. Much pondering on rib installation on the starboard side where it meets the bulkhead that will support the steering station. Not that difficult an issue but some thinking ahead required on how the steering wheel box and side decks attach to the aft end of the foredeck. Too early to declare victory but I believe I got it right.
*Edit 5/7/2012: The rib that is just aft of the windshield blocking appears to be unnecessary. The foredeck will be trimmed back to the windshield frame on the port and the middle sections.
*Edit 1/3/2013: I screwed up installing the plywood backing for the port and starboard windshield frame landing points. The pictured plywood for these frames sweep back about 145 degrees from the awartship plywood backing for the center windshield. Too severe an angle which should have been about 164 degrees.
Foredeck insulation
The blue styrofoam was 13/16 " thick thus too tall to fit between my laminated ribs which were slightly less than 3/4" thick. I used my surface planer to knock down the thickness of the insulation so it stood slightly proud between the ribs. Though the foam seemed easy to plane, I'm not sure how well the planer blades tolerated the foam's components.
I used a table saw to cut the foam into 3 5/8' strips to fit between the ribs. I used spacers when installing the ribs thus my care was rewarded as the foam strips fit without having to fuss with their widths. Some excitement in cutting the foam when the just cut strip was very succeptable to kick back if not controlled properly. Though a feather weight foam strip being expelled from the table saw posed little danger, it instinctly scared the dickens out of me as I ducked for cover.
The foam dust apparently had a static charge on it as the stuff stuck to vertical sufaces. Yup, I wore a respirator but looked like I had a blue snow cone on top of my head.
Before installing the foam, I coated the foredeck interior surfaces with epoxy to provide some moisture protection to the 4mm bottom panels and laminated ribs. I installed the foam into the wet epoxy, put some boards down on the foam and provided weight via limestone blocks. The cured epoxy held the foam tightly, at least in the short term.
Using a long board with 40 grit paper I leveled the foam with the tops of the ribs. The foam gives one a useful perspective of rib height and I found one rib that was standing proud probably from a wood scrap under it when epoxied in place. Epoxy was applied to the underside of the 6mm top plywood panels for moisture protection and perhaps some adherence to the foam thus meeting a requirement of "sandwich" construction in that the core is attached to both skins. Since the foredeck has ribs running throughout it thus a torsion box, it is academic whether the core is firmly attached to the inner and outer skins but it is always fun to find something else to postulate over.
The second of the two 1" wide ribs at the mid length location of the foredeck was necessary to correct an error I made in locating a rib (in relationship to the rib for the butt joint) at the point that the foredeck rests on the mahogany beam. Before correcting this error, I couldn't space the 1" wide ribs consistently to provide the mounting points for the decorative maghogany strips that will be installed on the interior of the foredeck. When I butt up the 6mm top panels, I will use the second rib for the mounting point thus make me feel that my measuring error provided a real or imagined strength benefit as the butt joints are now staggered over two ribs. However, the seam for the butt joint will now need to be glassed and faired. More weight and work as a consequence of my error. Perhaps I should just cover the bottom sheet's butt joint with the prescribed mahogany strip and live with a modest spacing error between two strips. Not sure if this paragraph makes sense but I lack the ability to explain it clearer.
In conclusion, the rib and decorative covering mahogany strip occurring at the plywood butt joint are the center of the universe when laying out the ribs . I got fixated on the rib occurring at the 1 3/4" wide main mahogany beam which led to getting the 1" rib locations out of sorts in regards to a dead on spacing between the decorative mahogany strips.
Though the plans prescribed 3" wide laminated plywood for the landing spot for the windshield, I made them 4' wide to give me wiggle room in response to my proclivity for foredeck measurement errors. Once the windshield is located, I can trim back back any excess on the port side plywood. Tom's plans specify how much the outer windshield frames sweep back from the center window thus how to position the port and starboard windshield landing spots. Much pondering on rib installation on the starboard side where it meets the bulkhead that will support the steering station. Not that difficult an issue but some thinking ahead required on how the steering wheel box and side decks attach to the aft end of the foredeck. Too early to declare victory but I believe I got it right.
*Edit 5/7/2012: The rib that is just aft of the windshield blocking appears to be unnecessary. The foredeck will be trimmed back to the windshield frame on the port and the middle sections.
*Edit 1/3/2013: I screwed up installing the plywood backing for the port and starboard windshield frame landing points. The pictured plywood for these frames sweep back about 145 degrees from the awartship plywood backing for the center windshield. Too severe an angle which should have been about 164 degrees.