Re: Micro bulkhead option
Glen - I'm building to plans, but I'll certainly at least build
fillets all around the bulkheads's sides. I'm using 10 mm ply all
around, with double thickness bottom.
I have a lot of tape that I might use (9 oz biaxial) to reinforce
everything. The added weight would be almost nothing... but the added
time is not going to be marginal. Consider that you'll have to fair
the tape weave - a nasty job.
By the way, my wife will have her exam in 2 days... Please wish her
the best of luck, and welcome me back to boatbuilding by then!
Best, Pippo
fillets all around the bulkheads's sides. I'm using 10 mm ply all
around, with double thickness bottom.
I have a lot of tape that I might use (9 oz biaxial) to reinforce
everything. The added weight would be almost nothing... but the added
time is not going to be marginal. Consider that you'll have to fair
the tape weave - a nasty job.
By the way, my wife will have her exam in 2 days... Please wish her
the best of luck, and welcome me back to boatbuilding by then!
Best, Pippo
--- Inbolger@egroups.com, glen_gibson@3... wrote:
>
>
> I'm planning on purchasing the wood for and starting construction
on
my hull
> early next month (I've been working on the masts, fun stuff). I've
been giving
> some thought to the bulkheads. My boat was going to be all 3/8"
marine, but I'm
> considering going with 1/2" bulkheads, no framing lumber, and using
nice fillets
> with fiberglass cloth to reinforce the bulkhead/side/bottom
junctions. Similar
> to the way Sam Devlin builds his boats (www.devlinboat.com). Both
his 16 and
> 18 foot sailboats, Nancy's China and WinterWren, use this method.
>
> Has anyone done such a thing? I thought I'd heard of someone
doing
it this
> way. I'm not looking to save time, in fact this might take
slightly longer.
> But I think this would look much better, be easier to clean, and at
least as
> strong, if not stronger (especially vs Bolgers specified 1/4"
sides/bulkheads).
> Bow bulkhead would be double, or maybe even triple 1/2" ply.
>
> Any thoughts would be appreciated. Thanks in advance!!!
>
> Glen Gibson
> Waiting for the kids to be out of school so I can take over the
garage ;-)
--- Inbolger@egroups.com, glen_gibson@3... wrote:
My 30-foot bolger is designed with 1/2 ply bull and bulkheads,
Attachment of buldheads to hull is with fillets; no tape was used
although I think that would be a good idea. It's a double chine hull
and the chines are tack and tape -- lots of tape. There's also a
solid
wood longitudinal in the middle of the bilge panel and lots of for
and
awd sringers in the bottom and deck.
One response is right; it is difficult to hold everything in place
with temporary screw or nails into the 1/2 inch bulkheads...
Gary Blankenship
Tallahassee, FL
>marine, but I'm
> My boat was going to be all 3/8"
> considering going with 1/2" bulkheads, no framing lumber, and usingnice fillets
> with fiberglass cloth to reinforce the bulkhead/side/bottomjunctions.
My 30-foot bolger is designed with 1/2 ply bull and bulkheads,
Attachment of buldheads to hull is with fillets; no tape was used
although I think that would be a good idea. It's a double chine hull
and the chines are tack and tape -- lots of tape. There's also a
solid
wood longitudinal in the middle of the bilge panel and lots of for
and
awd sringers in the bottom and deck.
One response is right; it is difficult to hold everything in place
with temporary screw or nails into the 1/2 inch bulkheads...
Gary Blankenship
Tallahassee, FL
To:bolger@egroups.com
From:glen_gibson@...
Date sent: Fri, 19 May 2000 09:24:47 -0700
Send reply to:bolger@egroups.com
Subject: [bolger] Micro bulkhead option
This is common practice in ply racing dinghies and powerboats
which are highly stressed Glen. I have used this method several
times.
I am certain that it will be very strong if properly done.
We trust this method to join the sides don't we?
I think a 1/2 inch bottom would be a minimum though.
Don
From:glen_gibson@...
Date sent: Fri, 19 May 2000 09:24:47 -0700
Send reply to:bolger@egroups.com
Subject: [bolger] Micro bulkhead option
This is common practice in ply racing dinghies and powerboats
which are highly stressed Glen. I have used this method several
times.
I am certain that it will be very strong if properly done.
We trust this method to join the sides don't we?
I think a 1/2 inch bottom would be a minimum though.
Don
>
>
> I'm planning on purchasing the wood for and starting construction on my hull
> early next month (I've been working on the masts, fun stuff). I've been giving
> some thought to the bulkheads. My boat was going to be all 3/8" marine, but I'm
> considering going with 1/2" bulkheads, no framing lumber, and using nice fillets
> with fiberglass cloth to reinforce the bulkhead/side/bottom junctions. Similar
> to the way Sam Devlin builds his boats (www.devlinboat.com). Both his 16 and
> 18 foot sailboats, Nancy's China and WinterWren, use this method.
>
> Has anyone done such a thing? I thought I'd heard of someone doing it this
> way. I'm not looking to save time, in fact this might take slightly longer.
> But I think this would look much better, be easier to clean, and at least as
> strong, if not stronger (especially vs Bolgers specified 1/4" sides/bulkheads).
> Bow bulkhead would be double, or maybe even triple 1/2" ply.
>
> Any thoughts would be appreciated. Thanks in advance!!!
>
> Glen Gibson
> Waiting for the kids to be out of school so I can take over the garage ;-)
>
>
>
> ------------------------------------------------------------------------
> The world's largest musician community, with over 50,000 gear
> reviews and over 15,000 pages of content, is a click away.
>http://click.egroups.com/1/3737/10/_/3457/_/958753650/
> ------------------------------------------------------------------------
>
>
>
Talk like this must be a leading source of grey hair among designers!
First, I'm not sure if you mean to eliminate the longitudinal
stringers (chine logs, etc.) Don't. Don't. Don't!
As for the bulkheads, You might borrow an idea the Bruce Kirby used
for his Norwalk Island Sharpies. He had the regular bulkhead of, say,
1/2" ply. Then he put a another layer of ply on each side. These were
about 2-3 inches wide. So the finished bulkhead is 1 1/2 inches thick
around the outside perimeter. The total amount of wood is about the
same as the Bolger method using natural lumber, and he feels it is
stronger. In the boat I saw, the edges of the doublings had been
nicely rounded over so they appeared more as moldings than as
reenforcements.
There have been comments on this list that the bottom of a Micro
built to the plans is fairly flexible. This suggests to me that
leaving out some of the stiffening is not a good idea.
Peter
First, I'm not sure if you mean to eliminate the longitudinal
stringers (chine logs, etc.) Don't. Don't. Don't!
As for the bulkheads, You might borrow an idea the Bruce Kirby used
for his Norwalk Island Sharpies. He had the regular bulkhead of, say,
1/2" ply. Then he put a another layer of ply on each side. These were
about 2-3 inches wide. So the finished bulkhead is 1 1/2 inches thick
around the outside perimeter. The total amount of wood is about the
same as the Bolger method using natural lumber, and he feels it is
stronger. In the boat I saw, the edges of the doublings had been
nicely rounded over so they appeared more as moldings than as
reenforcements.
There have been comments on this list that the bottom of a Micro
built to the plans is fairly flexible. This suggests to me that
leaving out some of the stiffening is not a good idea.
Peter
I, too, would not try building the bulkheads without the framing
lumber. The framing lumber gives you something that screws or ring
nails can bite into and hold the boat together. Epoxy is strong
stuff and might do all right by itself, but how are you going to hold
the pieces together while it sets up? If you notice, the plans all
put the framing lumber where it is least noticeable. The only
framing you can readily see from inside is the aft cabin bulkhead.
If you do a nice job on this, the framing lumber is like trim (or
cover it with another sheet of plywood inside).
Tom Etherington
tetherin@...
-I'm
lumber. The framing lumber gives you something that screws or ring
nails can bite into and hold the boat together. Epoxy is strong
stuff and might do all right by itself, but how are you going to hold
the pieces together while it sets up? If you notice, the plans all
put the framing lumber where it is least noticeable. The only
framing you can readily see from inside is the aft cabin bulkhead.
If you do a nice job on this, the framing lumber is like trim (or
cover it with another sheet of plywood inside).
Tom Etherington
tetherin@...
-I'm
> considering going with 1/2" bulkheads, no framing lumber, and usingnice fillets
> with fiberglass cloth to reinforce the bulkhead/side/bottomjunctions
Glen,
I would expect that your plan might be weaker. Any edge fasteners won't be
much good, and fillets aside, your joint will be smaller. The edges of
your bulkheads will be less reinforced (thinner by 1/2). Your boat will be
heavy; with all that extra material wasting in the middle - you want that
on the edges where the loads are. Pound for pound, the frame thickened at
the edges can't be beat.
Gregg
At 09:24 AM 5/19/2000 -0700, you wrote:
I would expect that your plan might be weaker. Any edge fasteners won't be
much good, and fillets aside, your joint will be smaller. The edges of
your bulkheads will be less reinforced (thinner by 1/2). Your boat will be
heavy; with all that extra material wasting in the middle - you want that
on the edges where the loads are. Pound for pound, the frame thickened at
the edges can't be beat.
Gregg
At 09:24 AM 5/19/2000 -0700, you wrote:
>I'm planning on purchasing the wood for and starting construction on my hullgiving
>early next month (I've been working on the masts, fun stuff). I've been
>some thought to the bulkheads. My boat was going to be all 3/8" marine,but I'm
>considering going with 1/2" bulkheads, no framing lumber, and using nicefillets
>with fiberglass cloth to reinforce the bulkhead/side/bottom junctions.Similar
>to the way Sam Devlin builds his boats (www.devlinboat.com). Both his 16and
>18 foot sailboats, Nancy's China and WinterWren, use this method.sides/bulkheads).
>
>Has anyone done such a thing? I thought I'd heard of someone doing it this
>way. I'm not looking to save time, in fact this might take slightly longer.
>But I think this would look much better, be easier to clean, and at least as
>strong, if not stronger (especially vs Bolgers specified 1/4"
>Bow bulkhead would be double, or maybe even triple 1/2" ply.
>
>Any thoughts would be appreciated. Thanks in advance!!!
>
>Glen Gibson
>Waiting for the kids to be out of school so I can take over the garage ;-)
>
>------------------------------------------------------------------------
>The world's largest musician community, with over 50,000 gear
>reviews and over 15,000 pages of content, is a click away.
>http://click.egroups.com/1/3737/10/_/3457/_/958753650/
>------------------------------------------------------------------------
Glen,
I have just about completed my bulkheads and am about to go three
dimensional with the "Firefly". My 1/4 inch bulkheads seem to be
sufficient as they are backed up on all sides with framing material
to
take the fastenings. The framing material will hold the screws
better
than 1/2" ply. Do you plan on filleting and glass taping the frames
as
well? It seems to be adding a lot more weight above the water line
than is necessary.
I am using the 1/4" sides, and frames, and will have a double
bottom and 3/8 deck.
David Jost
I have just about completed my bulkheads and am about to go three
dimensional with the "Firefly". My 1/4 inch bulkheads seem to be
sufficient as they are backed up on all sides with framing material
to
take the fastenings. The framing material will hold the screws
better
than 1/2" ply. Do you plan on filleting and glass taping the frames
as
well? It seems to be adding a lot more weight above the water line
than is necessary.
I am using the 1/4" sides, and frames, and will have a double
bottom and 3/8 deck.
David Jost
I'm planning on purchasing the wood for and starting construction on my hull
early next month (I've been working on the masts, fun stuff). I've been giving
some thought to the bulkheads. My boat was going to be all 3/8" marine, but I'm
considering going with 1/2" bulkheads, no framing lumber, and using nice fillets
with fiberglass cloth to reinforce the bulkhead/side/bottom junctions. Similar
to the way Sam Devlin builds his boats (www.devlinboat.com). Both his 16 and
18 foot sailboats, Nancy's China and WinterWren, use this method.
Has anyone done such a thing? I thought I'd heard of someone doing it this
way. I'm not looking to save time, in fact this might take slightly longer.
But I think this would look much better, be easier to clean, and at least as
strong, if not stronger (especially vs Bolgers specified 1/4" sides/bulkheads).
Bow bulkhead would be double, or maybe even triple 1/2" ply.
Any thoughts would be appreciated. Thanks in advance!!!
Glen Gibson
Waiting for the kids to be out of school so I can take over the garage ;-)
early next month (I've been working on the masts, fun stuff). I've been giving
some thought to the bulkheads. My boat was going to be all 3/8" marine, but I'm
considering going with 1/2" bulkheads, no framing lumber, and using nice fillets
with fiberglass cloth to reinforce the bulkhead/side/bottom junctions. Similar
to the way Sam Devlin builds his boats (www.devlinboat.com). Both his 16 and
18 foot sailboats, Nancy's China and WinterWren, use this method.
Has anyone done such a thing? I thought I'd heard of someone doing it this
way. I'm not looking to save time, in fact this might take slightly longer.
But I think this would look much better, be easier to clean, and at least as
strong, if not stronger (especially vs Bolgers specified 1/4" sides/bulkheads).
Bow bulkhead would be double, or maybe even triple 1/2" ply.
Any thoughts would be appreciated. Thanks in advance!!!
Glen Gibson
Waiting for the kids to be out of school so I can take over the garage ;-)