Re: [bolger] Re:Dakota / Wyo
Sounds like the Dakota is built different than the Wyo. The Wyo has 3 layers of 1/2" staggered at 8" intervals. All panels except the very front are laid width ways down the length and there is no center shoe. In fact there is nothing on the bottom, it's perfectly flat and smooth.
You lay out the entire bottom flat to glue up and finish, then turn over. Next mount the bulkheads and test fit the side panels. As you put the side panels and intercoastals on you start from the rear and work forward, jacking it up to conform. The rear 2/3 of the bottom as a flat run so that should stiffen it up enough to allow the jacking procedure to work, I hope.
I figured I could lay out the bottom in three pieces by just using screws, not gluing the seams in three areas until it's flipped. That way instead of weighing 2000 lbs, each piece would by 600 or 700 and much easier and safer to handle. Once turned, line it back up, glue and nail into place. It has to be jacked up to about 45 degrees on each side to finish the chine so I can finish the two splices at the same time.
I figure on just temporarily drawing an outline on the bottom to guide the epoxy/glass proceedures but not actually cut the bottom profile until all is turned and glued up. That way pry bars and such won't mar up the actually chine edge.
I may go even heavier or double layer on the bottom glass. When a 10,000 pound boat scrubs the bottom, it'll take a lot of glass to keep it protected.
Thanks for the information Vince. This big of a boat will be a challenge physically. I'm looking forward to it.
Jeff
[Non-text portions of this message have been removed]
You lay out the entire bottom flat to glue up and finish, then turn over. Next mount the bulkheads and test fit the side panels. As you put the side panels and intercoastals on you start from the rear and work forward, jacking it up to conform. The rear 2/3 of the bottom as a flat run so that should stiffen it up enough to allow the jacking procedure to work, I hope.
I figured I could lay out the bottom in three pieces by just using screws, not gluing the seams in three areas until it's flipped. That way instead of weighing 2000 lbs, each piece would by 600 or 700 and much easier and safer to handle. Once turned, line it back up, glue and nail into place. It has to be jacked up to about 45 degrees on each side to finish the chine so I can finish the two splices at the same time.
I figure on just temporarily drawing an outline on the bottom to guide the epoxy/glass proceedures but not actually cut the bottom profile until all is turned and glued up. That way pry bars and such won't mar up the actually chine edge.
I may go even heavier or double layer on the bottom glass. When a 10,000 pound boat scrubs the bottom, it'll take a lot of glass to keep it protected.
Thanks for the information Vince. This big of a boat will be a challenge physically. I'm looking forward to it.
Jeff
[Non-text portions of this message have been removed]
Jeff,
1. I built a "strongback" of heavy timbers placed in the athwart
(crosswise) direction every 1 1/2 meters. (I had some salvaged 4" x 6"
X 12' fir beams). The timbers were shimmed progressively higher off the
floor toward the ends to the curvature of the bottom (from the profile
view, NOT from the topsides expansion). I used 2" x 6" blocking and
bracing to lock them solidly in place. I stretched a string and marked
the centerline on each strongback member. I measured out from the
centerline 1/2 the width of the shoe each side of center on each
strongback member and added some 2" material on the tops of the
strongbacks outboard of the shoe. I tacked on squares of polyethylene in
places where glue might squeeze out onto the strongback.
I think it shows fairly well in this file picture (If this long URL
wraps around you may have to copy and paste it):
http://groups.yahoo.com/group/bolger/files/Dakota/2%20placing%20starboard%20side%20panel.jpg
2. I set up a 40' workbench of planks on sawhorses alongside the
strongback. This made it much easier to splice the sheets together, put
on the fiberglass sheathing, sand fill and finish the bottom panels,
etc. at a comfortable working height.
3. I made up 40 foot panels for each layer because the long panels bend
more easily. (Like the difference between a pencil and a fly rod).
4. I ripped 10 sheets in half lengthwise and spliced 4 long panels 2ft.
x 40ft. for the CENTER SHOE. I clamped these 40 ft. panels together with
the edges aligned, laid out the curve from the plan and cut it with my
circular saw. (My 7 1/4" saw blade didn't quite cut through the bottom
panel, but it left a saw kerf I could follow to finish the cut later).
I pre-glassed and finished the one on top. flipped it over onto the
center of the strongback. I slathered on thickened epoxy and added the
next layers. I used lots of weight and clamps to get each layer snug
against the one below. Once I had enough thickness for galvanized deck
screws, I used those as well.
5. I spliced six panels 4 feet by 40 feet, one on top of the other. I
took care to keep the edges as straight as possible. I sheathed, filled
and prefinished the top panel as it would be flipped over and become 1/2
of the first bottom layer.
6. I clamped all six layers together with all the edges aligned, layed
out the curvature of 1/2 the bottom from the expansions provided on the
plan, and sawed the curve with a circular saw.
7. I slathered glue on 1/2 of the center shoe. Then I flipped the top
panel over finished side down and laid it on the strongback. The 40 foot
long panels are quite flexible. I used weight and screws into the center shoe.
8. I flipped the next panel over on the workbench first and then
pre-fiberglassed and finished it. I spread glue on the other half of the
center shoe then slid the second bottom panel over onto the strongback
and secured it with weight and screws into the center shoe.
I won't go on, but the basic idea is that you build the curvature in as
you lay it up one layer at a time. When you get ready to bend on the
topsides after the chine logs are in place, you can still make minor
adjustments to the curve of the bottom with a jack, pry pole, or shims.
It is somewhat flexible even after the topsides are on and doesn't
really stiffen up until you get the bullkheads, berth fronts, cabinetry
etc. built in. Once the ceiling and roof beams are on it is like a rock.
BTW, I'm with you on the weight of glass for this size boat --
especially on the bottom. (Abrasion and impact resistance)
Vince Chew
1. I built a "strongback" of heavy timbers placed in the athwart
(crosswise) direction every 1 1/2 meters. (I had some salvaged 4" x 6"
X 12' fir beams). The timbers were shimmed progressively higher off the
floor toward the ends to the curvature of the bottom (from the profile
view, NOT from the topsides expansion). I used 2" x 6" blocking and
bracing to lock them solidly in place. I stretched a string and marked
the centerline on each strongback member. I measured out from the
centerline 1/2 the width of the shoe each side of center on each
strongback member and added some 2" material on the tops of the
strongbacks outboard of the shoe. I tacked on squares of polyethylene in
places where glue might squeeze out onto the strongback.
I think it shows fairly well in this file picture (If this long URL
wraps around you may have to copy and paste it):
http://groups.yahoo.com/group/bolger/files/Dakota/2%20placing%20starboard%20side%20panel.jpg
2. I set up a 40' workbench of planks on sawhorses alongside the
strongback. This made it much easier to splice the sheets together, put
on the fiberglass sheathing, sand fill and finish the bottom panels,
etc. at a comfortable working height.
3. I made up 40 foot panels for each layer because the long panels bend
more easily. (Like the difference between a pencil and a fly rod).
4. I ripped 10 sheets in half lengthwise and spliced 4 long panels 2ft.
x 40ft. for the CENTER SHOE. I clamped these 40 ft. panels together with
the edges aligned, laid out the curve from the plan and cut it with my
circular saw. (My 7 1/4" saw blade didn't quite cut through the bottom
panel, but it left a saw kerf I could follow to finish the cut later).
I pre-glassed and finished the one on top. flipped it over onto the
center of the strongback. I slathered on thickened epoxy and added the
next layers. I used lots of weight and clamps to get each layer snug
against the one below. Once I had enough thickness for galvanized deck
screws, I used those as well.
5. I spliced six panels 4 feet by 40 feet, one on top of the other. I
took care to keep the edges as straight as possible. I sheathed, filled
and prefinished the top panel as it would be flipped over and become 1/2
of the first bottom layer.
6. I clamped all six layers together with all the edges aligned, layed
out the curvature of 1/2 the bottom from the expansions provided on the
plan, and sawed the curve with a circular saw.
7. I slathered glue on 1/2 of the center shoe. Then I flipped the top
panel over finished side down and laid it on the strongback. The 40 foot
long panels are quite flexible. I used weight and screws into the center shoe.
8. I flipped the next panel over on the workbench first and then
pre-fiberglassed and finished it. I spread glue on the other half of the
center shoe then slid the second bottom panel over onto the strongback
and secured it with weight and screws into the center shoe.
I won't go on, but the basic idea is that you build the curvature in as
you lay it up one layer at a time. When you get ready to bend on the
topsides after the chine logs are in place, you can still make minor
adjustments to the curve of the bottom with a jack, pry pole, or shims.
It is somewhat flexible even after the topsides are on and doesn't
really stiffen up until you get the bullkheads, berth fronts, cabinetry
etc. built in. Once the ceiling and roof beams are on it is like a rock.
BTW, I'm with you on the weight of glass for this size boat --
especially on the bottom. (Abrasion and impact resistance)
Vince Chew
Jeff --
I'm curious why you're with this weight of glass. Durability? Ding resistance?
I'm curious why you're with this weight of glass. Durability? Ding resistance?
>175 board feet of 1 1/2 Fir @ 3.80 per BF. $ 665.00
>22 sheets Meranti @ 55.00 each includes shipping. $1210.00
>78 sheets MDO @ $40.56 each including sales tax. $3163.00
>30 gals epoxy (Raka) $ 995.00
>100 yards 8.75 T cloth $ 697.00
A question for Vince who's building the Dakota.
Was it hard to get the 1 1/2" bottom to curve up to meet the sides as
you attached them?
Seems it would be very stiff and hard to get it to conform to the
side shape. Especially since it's glued up flat on the floor.
****************************************
Also, did a final tally on the Wyo for Plywood. I had estimated
before but looks still like 100 sheets is correct. I've decide that
I would go for a mixture of MDO and Meranti. Meranti for above the
shear and interior bulkheads, MDO for all else. That will give me
the option for a mahogany look on the topsides if I wanted to just
epoxy/varnish. Interior would be varnished mahogany look above the
shear line, painted below. Roof panels will all be MDO as is the
lower sides and bottom.
175 board feet of 1 1/2 Fir @ 3.80 per BF. $ 665.00
22 sheets Meranti @ 55.00 each includes shipping. $1210.00
78 sheets MDO @ $40.56 each including sales tax. $3163.00
30 gals epoxy (Raka) $ 995.00
100 yards 8.75 T cloth $ 697.00
Looks like I need to spend around $6600 to get things rolling. Of
course lot's of SS ring shank nails, sand paper, screws, etc.
Finances in order, time table ticking away, wife excited, I'm
excited, kids confused, and my Boger Nymph almost done so I guess
it's time to get out the check book and........
Jeff
Was it hard to get the 1 1/2" bottom to curve up to meet the sides as
you attached them?
Seems it would be very stiff and hard to get it to conform to the
side shape. Especially since it's glued up flat on the floor.
****************************************
Also, did a final tally on the Wyo for Plywood. I had estimated
before but looks still like 100 sheets is correct. I've decide that
I would go for a mixture of MDO and Meranti. Meranti for above the
shear and interior bulkheads, MDO for all else. That will give me
the option for a mahogany look on the topsides if I wanted to just
epoxy/varnish. Interior would be varnished mahogany look above the
shear line, painted below. Roof panels will all be MDO as is the
lower sides and bottom.
175 board feet of 1 1/2 Fir @ 3.80 per BF. $ 665.00
22 sheets Meranti @ 55.00 each includes shipping. $1210.00
78 sheets MDO @ $40.56 each including sales tax. $3163.00
30 gals epoxy (Raka) $ 995.00
100 yards 8.75 T cloth $ 697.00
Looks like I need to spend around $6600 to get things rolling. Of
course lot's of SS ring shank nails, sand paper, screws, etc.
Finances in order, time table ticking away, wife excited, I'm
excited, kids confused, and my Boger Nymph almost done so I guess
it's time to get out the check book and........
Jeff