Re: Birdwatcher-2 pictures
Hello Bob,
Thank you very much for posting the update! I came across your site
while searching for "Birdwatcher", after I read the WoodenBoat article.
Your work looks very good and it's really inspiring! It sure helps
while I'm contemplating this design. Good luck on your boatbuilding.
I'm looking forward to the next steps...
Greets, Leon Steyns.
Thank you very much for posting the update! I came across your site
while searching for "Birdwatcher", after I read the WoodenBoat article.
Your work looks very good and it's really inspiring! It sure helps
while I'm contemplating this design. Good luck on your boatbuilding.
I'm looking forward to the next steps...
Greets, Leon Steyns.
--- Inbolger@yahoogroups.com, Bob Larkin <boblark@p...> wrote:
>
> I have updated the building photos at
>http://www.proaxis.com/~boblark/bw2_main.htm
> The recent ones have their links marked "new."
>
> The boat is almost ready for the polycarbonate and inner walls.
>
> Bob Larkin
> Corvallis, Oregon
>
John, the beams that I made up were 2 inches wide and had cheapy 1/8
inch Luan doorskin on each side of the 1-inch pink foam, all as a
sandwich. I posted (temporarily) a picture of one of these at
http://www.proaxis.com/~boblark/bw2_foam_beam1.jpgThe Luan material
was interesting, as it has almost no bending resistance on its own!
I was really trying to evaluate different gluing systems and their
water resistance, but it also showed the strength of the struture. I
call it a "beam," since the foam has the same ability to increase
strength as the web of an I-beam. In both cases the bending strength
goes up as the square of the thickness, as long as the structrure
fails by tension in the outside surface, which the Luan will. A good
piece of 1/4-inch plywood might well result in the foam crushing,
which is the other failure mode. In any event, the 2-inch wide beam,
10 inches long would support a weight of 15 lb or so.
Other than playing with glues, the conclusion was that a sandwich of
1/4 inch ply, 1-inch foam, and 1/8 inch ply is a major structural
improvement over the 1/4 plywood. I guess people that build balsa
(and other) cored decks figured this out a long time ago.
Bob
--- Inbolger@yahoogroups.com, john h wright <jhargrovewright2@j...>
wrote:
inch Luan doorskin on each side of the 1-inch pink foam, all as a
sandwich. I posted (temporarily) a picture of one of these at
http://www.proaxis.com/~boblark/bw2_foam_beam1.jpgThe Luan material
was interesting, as it has almost no bending resistance on its own!
I was really trying to evaluate different gluing systems and their
water resistance, but it also showed the strength of the struture. I
call it a "beam," since the foam has the same ability to increase
strength as the web of an I-beam. In both cases the bending strength
goes up as the square of the thickness, as long as the structrure
fails by tension in the outside surface, which the Luan will. A good
piece of 1/4-inch plywood might well result in the foam crushing,
which is the other failure mode. In any event, the 2-inch wide beam,
10 inches long would support a weight of 15 lb or so.
Other than playing with glues, the conclusion was that a sandwich of
1/4 inch ply, 1-inch foam, and 1/8 inch ply is a major structural
improvement over the 1/4 plywood. I guess people that build balsa
(and other) cored decks figured this out a long time ago.
Bob
--- Inbolger@yahoogroups.com, john h wright <jhargrovewright2@j...>
wrote:
>could
> I have not bought Dow blue foam in a few years but at that time it
> be bought in many thicknesses and in different densities(weights). My
> observation is that it is much more rigid (harder) and I think abetter
> material that the OC pink for most of our purposes. Does anyoneout
> there have better info than this. I am interested. Could youdescribe
> the test "beam" construction that you tested.I
>
> On Sat, 15 Oct 2005 18:07:51 -0000 "Bob larkin" <boblark@p...>
> writes:
> Peter, thanks for the comments.
>
> Good question about the foam. In the local stores, I only see the
> Owens-Corning Formular 150. I bought a sheet and made up some test
> beams, 2-inches wide. These were impressively strong, and I further
> tested it by walking (wearing sneakers) on the sheet laying on the
> floor. It left no permanent indication, other than from my dirty
> shoes. This is all not very scientific, but it looked better than
> thought the stuff would be! I have never seen the Dow Styrafoamblue
> type, and would like to learn more. Can you add to this, as I still
> can switch? There must be someone selling Dow in Oregon.
>
> Bob
>
>
I have not bought Dow blue foam in a few years but at that time it could
be bought in many thicknesses and in different densities (weights). My
observation is that it is much more rigid (harder) and I think a better
material that the OC pink for most of our purposes. Does anyone out
there have better info than this. I am interested. Could you describe
the test "beam" construction that you tested.
On Sat, 15 Oct 2005 18:07:51 -0000 "Bob larkin" <boblark@...>
writes:
Peter, thanks for the comments.
Good question about the foam. In the local stores, I only see the
Owens-Corning Formular 150. I bought a sheet and made up some test
beams, 2-inches wide. These were impressively strong, and I further
tested it by walking (wearing sneakers) on the sheet laying on the
floor. It left no permanent indication, other than from my dirty
shoes. This is all not very scientific, but it looked better than I
thought the stuff would be! I have never seen the Dow Styrafoam blue
type, and would like to learn more. Can you add to this, as I still
can switch? There must be someone selling Dow in Oregon.
Bob
--- Inbolger@yahoogroups.com, "Peter Lenihan" <peterlenihan@h...>
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[Non-text portions of this message have been removed]
be bought in many thicknesses and in different densities (weights). My
observation is that it is much more rigid (harder) and I think a better
material that the OC pink for most of our purposes. Does anyone out
there have better info than this. I am interested. Could you describe
the test "beam" construction that you tested.
On Sat, 15 Oct 2005 18:07:51 -0000 "Bob larkin" <boblark@...>
writes:
Peter, thanks for the comments.
Good question about the foam. In the local stores, I only see the
Owens-Corning Formular 150. I bought a sheet and made up some test
beams, 2-inches wide. These were impressively strong, and I further
tested it by walking (wearing sneakers) on the sheet laying on the
floor. It left no permanent indication, other than from my dirty
shoes. This is all not very scientific, but it looked better than I
thought the stuff would be! I have never seen the Dow Styrafoam blue
type, and would like to learn more. Can you add to this, as I still
can switch? There must be someone selling Dow in Oregon.
Bob
--- Inbolger@yahoogroups.com, "Peter Lenihan" <peterlenihan@h...>
> but I just have to ask why you went with the pink styrofoam insteadBolger rules!!!
> of the denser blue styrofoam?
>
> Continued building success!!
>
> Sincerely,
>
> Peter Lenihan
>
- no cursing, flaming, trolling, spamming, respamming, or flogging dead
horses
- stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
- Pls add your comments at the TOP, SIGN your posts, and snip away
- Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax:
(978) 282-1349
- Unsubscribe:bolger-unsubscribe@yahoogroups.com
- Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
SPONSORED LINKS Boating safety Alaska outdoors Boating magazine
Great outdoors
YAHOO! GROUPS LINKS
Visit your group "bolger" on the web.
To unsubscribe from this group, send an email to:
bolger-unsubscribe@yahoogroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
I've used the blue and the pink foam for boatbuilding and windsurfer board
building and weighed samples of both for comparison. They weighed the same
and appeared to be the same texture etc. I heard the pink was lighter,
which was why I weighed them. Wherever I've bought it only one color was
offered.
Gary Lepak
building and weighed samples of both for comparison. They weighed the same
and appeared to be the same texture etc. I heard the pink was lighter,
which was why I weighed them. Wherever I've bought it only one color was
offered.
Gary Lepak
----- Original Message -----
From: "Peter Lenihan" <peterlenihan@...>
>
> Beautiful workmanship Mr.Larkin! Thanks for the pictures/up-dates
> but I just have to ask why you went with the pink styrofoam instead
> of the denser blue styrofoam?
>
Peter, thanks for the comments.
Good question about the foam. In the local stores, I only see the
Owens-Corning Formular 150. I bought a sheet and made up some test
beams, 2-inches wide. These were impressively strong, and I further
tested it by walking (wearing sneakers) on the sheet laying on the
floor. It left no permanent indication, other than from my dirty
shoes. This is all not very scientific, but it looked better than I
thought the stuff would be! I have never seen the Dow Styrafoam blue
type, and would like to learn more. Can you add to this, as I still
can switch? There must be someone selling Dow in Oregon.
Bob
--- Inbolger@yahoogroups.com, "Peter Lenihan" <peterlenihan@h...>
Good question about the foam. In the local stores, I only see the
Owens-Corning Formular 150. I bought a sheet and made up some test
beams, 2-inches wide. These were impressively strong, and I further
tested it by walking (wearing sneakers) on the sheet laying on the
floor. It left no permanent indication, other than from my dirty
shoes. This is all not very scientific, but it looked better than I
thought the stuff would be! I have never seen the Dow Styrafoam blue
type, and would like to learn more. Can you add to this, as I still
can switch? There must be someone selling Dow in Oregon.
Bob
--- Inbolger@yahoogroups.com, "Peter Lenihan" <peterlenihan@h...>
> but I just have to ask why you went with the pink styrofoam instead
> of the denser blue styrofoam?
>
> Continued building success!!
>
> Sincerely,
>
> Peter Lenihan
>
--- Inbolger@yahoogroups.com, Bob Larkin <boblark@p...> wrote:
but I just have to ask why you went with the pink styrofoam instead
of the denser blue styrofoam?
Continued building success!!
Sincerely,
Peter Lenihan
>Beautiful workmanship Mr.Larkin! Thanks for the pictures/up-dates
> I have updated the building photos at
>http://www.proaxis.com/~boblark/bw2_main.htm
> The recent ones have their links marked "new."
>
> The boat is almost ready for the polycarbonate and inner walls.
>
> Bob Larkin
> Corvallis, Oregon
>
but I just have to ask why you went with the pink styrofoam instead
of the denser blue styrofoam?
Continued building success!!
Sincerely,
Peter Lenihan
Bob,
Tkanks for the update. I'm looking forward to seeing your progress on
that afterdeck.
Paul
Tkanks for the update. I'm looking forward to seeing your progress on
that afterdeck.
Paul
> I have updated the building photos at
>http://www.proaxis.com/~boblark/bw2_main.htm
I have updated the building photos at
http://www.proaxis.com/~boblark/bw2_main.htm
The recent ones have their links marked "new."
The boat is almost ready for the polycarbonate and inner walls.
Bob Larkin
Corvallis, Oregon
http://www.proaxis.com/~boblark/bw2_main.htm
The recent ones have their links marked "new."
The boat is almost ready for the polycarbonate and inner walls.
Bob Larkin
Corvallis, Oregon