Re: Anti-slap pad on Birdwatcher
I think I suggested that too.
In order to correct a problem, another difficulty is created, thus
cancelling out the original objective.....simplicity.
That was certainly the case with Oink, though I have the slight
excuse, that the original simplicity turned out to be a
liability....boat destructive pounding.
DonB
http://oink.kiwiwebhost.biz/
--- Inbolger@yahoogroups.com, "John B. Trussell" <John.Trussell@w...>
wrote:
laminate, fill, and carve an anti-slap pad, maybe a design other than
a modified flat bottomed boat would give you more bang for the buck.
In order to correct a problem, another difficulty is created, thus
cancelling out the original objective.....simplicity.
That was certainly the case with Oink, though I have the slight
excuse, that the original simplicity turned out to be a
liability....boat destructive pounding.
DonB
http://oink.kiwiwebhost.biz/
--- Inbolger@yahoogroups.com, "John B. Trussell" <John.Trussell@w...>
wrote:
> If you are willing to accept the shortcomings of flat bottomedboats, that's fine. If you are not, and if you are prepared to
laminate, fill, and carve an anti-slap pad, maybe a design other than
a modified flat bottomed boat would give you more bang for the buck.
>
> John T
I'm on record with the opinion that BW2 is a needless complication of BW1 and this mind set should probably be considered by anyone reading this.
If I understand PCB's published commentary on sharpies, the disadvantage of this hull shape is that, with the boat heeled, there is a pressure differential between the water moving over the bottom and the water moving over the side. The pressure differential generates eddies along the chine, producing excessive drag and interesting handling.
PCB's solution has been to match the curve of the bottom to the curve in the side. These matching curves reduce the pressure differential and produce a more efficient hull..(An alternative solution is to draw round chines, though this does not lend itself to plywood home building.)
The installation of an anti-slap pad would appear to change the curve of the bottom as the boat heels, and I can't begin to guess if this will have a significant (or even noticeable) impact on performance. However, I think I would wait for some real world feed back before I started reflexively adding pads to every flat bottomed boat.
I would also observe that people build flat bottomed boats because they are quick and simple. The simplicity comes with a price. Flat bottomed boats generally do not perform as well and are not as seaworthy as comparable round bottomed boats (the exception being for boats which operate in very shallow water). But round bottomed boats are much more time consuming and expensive to build than round bottomed boats; and flat bottomed boats perform well enough. The trade off in performance is offset by building savings.
If you are willing to accept the shortcomings of flat bottomed boats, that's fine. If you are not, and if you are prepared to laminate, fill, and carve an anti-slap pad, maybe a design other than a modified flat bottomed boat would give you more bang for the buck.
John T
If I understand PCB's published commentary on sharpies, the disadvantage of this hull shape is that, with the boat heeled, there is a pressure differential between the water moving over the bottom and the water moving over the side. The pressure differential generates eddies along the chine, producing excessive drag and interesting handling.
PCB's solution has been to match the curve of the bottom to the curve in the side. These matching curves reduce the pressure differential and produce a more efficient hull..(An alternative solution is to draw round chines, though this does not lend itself to plywood home building.)
The installation of an anti-slap pad would appear to change the curve of the bottom as the boat heels, and I can't begin to guess if this will have a significant (or even noticeable) impact on performance. However, I think I would wait for some real world feed back before I started reflexively adding pads to every flat bottomed boat.
I would also observe that people build flat bottomed boats because they are quick and simple. The simplicity comes with a price. Flat bottomed boats generally do not perform as well and are not as seaworthy as comparable round bottomed boats (the exception being for boats which operate in very shallow water). But round bottomed boats are much more time consuming and expensive to build than round bottomed boats; and flat bottomed boats perform well enough. The trade off in performance is offset by building savings.
If you are willing to accept the shortcomings of flat bottomed boats, that's fine. If you are not, and if you are prepared to laminate, fill, and carve an anti-slap pad, maybe a design other than a modified flat bottomed boat would give you more bang for the buck.
John T
----- Original Message -----
From: oarmandt
To:bolger@yahoogroups.com
Sent: Monday, May 09, 2005 6:48 PM
Subject: [bolger] Re: Anti-slap pad on Birdwatcher
The point is that Bolger's design catalog is filled with flat bottomed
boats and one of the most persistant criticisms is that they are noisy
at anchor. Here is a way to quiet the thing without undertaking
dubious major structural modifications or waiting for Mr. Bolger to
come out with a redesign. If the existing design is otherwise
suitable in most respects, the simple to execute anti-slap pad could
remove the noise objection and result in more builders getting a boat
they are satified with.
Maybe building a Vee bottom would be more time and material efficient.
This is a hobby, not a business, so efficiency is not highly valued.
I enjoy the building process at least as much as using the end
product. Carving this bit of sculpture was rather satisfying on its own.
Doug
--- Inbolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@y...> wrote:
> > > New photos in Bolger 5 under "Anti-slap Pad"...
>
> The pictures show a very neat job of building. Although I'm sure it
> will quite the bow somewhat, I wonder if, overall, it might not be
> just as easy to build a v-bottom boat in the first place. Or, one that
> is v-eed only in the bow.
>
> Peter
Bolger rules!!!
- no cursing, flaming, trolling, spamming, 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
------------------------------------------------------------------------------
Yahoo! Groups Links
a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/bolger/
b.. To unsubscribe from this group, send an email to:
bolger-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
------------------------------------------------------------------------------
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005
[Non-text portions of this message have been removed]
The point is that Bolger's design catalog is filled with flat bottomed
boats and one of the most persistant criticisms is that they are noisy
at anchor. Here is a way to quiet the thing without undertaking
dubious major structural modifications or waiting for Mr. Bolger to
come out with a redesign. If the existing design is otherwise
suitable in most respects, the simple to execute anti-slap pad could
remove the noise objection and result in more builders getting a boat
they are satified with.
Maybe building a Vee bottom would be more time and material efficient.
This is a hobby, not a business, so efficiency is not highly valued.
I enjoy the building process at least as much as using the end
product. Carving this bit of sculpture was rather satisfying on its own.
Doug
boats and one of the most persistant criticisms is that they are noisy
at anchor. Here is a way to quiet the thing without undertaking
dubious major structural modifications or waiting for Mr. Bolger to
come out with a redesign. If the existing design is otherwise
suitable in most respects, the simple to execute anti-slap pad could
remove the noise objection and result in more builders getting a boat
they are satified with.
Maybe building a Vee bottom would be more time and material efficient.
This is a hobby, not a business, so efficiency is not highly valued.
I enjoy the building process at least as much as using the end
product. Carving this bit of sculpture was rather satisfying on its own.
Doug
--- Inbolger@yahoogroups.com, "pvanderwaart" <pvanderwaart@y...> wrote:
> > > New photos in Bolger 5 under "Anti-slap Pad"...
>
> The pictures show a very neat job of building. Although I'm sure it
> will quite the bow somewhat, I wonder if, overall, it might not be
> just as easy to build a v-bottom boat in the first place. Or, one that
> is v-eed only in the bow.
>
> Peter
You have made a nice job of the bow pad Doug.
I'm in no way being critical of you, but I do wonder at the various
contortions being designed, to eliminate bow slap in a basic simple
hull. It has sort of reached the point in my opinion, where one gets
so involved with the solution to a problem, that one disappears up
ones own fundamental orifice....if you get my drift....that is,it
seems to me that a solution has been reached which is perhaps more
difficult than the thing it was designed to replace.
There is nothing difficult to building a round bow, giving a better
result aesthetically and performancewise.
I built the round bow onto my Micro Navigator, but it would have been
far easier if it had been designed into it at the beginning.
I think the nearest Bolger has got to a compromise and pleasing
solution is the filleted bow of Windermere. Even then I doubt that you
would save time and effort over a 'designed from the beginning' round bow.
DonB
http://oink.kiwiwebhost.biz/
I'm in no way being critical of you, but I do wonder at the various
contortions being designed, to eliminate bow slap in a basic simple
hull. It has sort of reached the point in my opinion, where one gets
so involved with the solution to a problem, that one disappears up
ones own fundamental orifice....if you get my drift....that is,it
seems to me that a solution has been reached which is perhaps more
difficult than the thing it was designed to replace.
There is nothing difficult to building a round bow, giving a better
result aesthetically and performancewise.
I built the round bow onto my Micro Navigator, but it would have been
far easier if it had been designed into it at the beginning.
I think the nearest Bolger has got to a compromise and pleasing
solution is the filleted bow of Windermere. Even then I doubt that you
would save time and effort over a 'designed from the beginning' round bow.
DonB
http://oink.kiwiwebhost.biz/
--- Inbolger@yahoogroups.com, "oarmandt" <oarman89@v...> wrote:
> New photos in Bolger 5 under "Anti-slap Pad" show the quieting pad on
> the bow of my Birdwatcher. I thought that this would be adaptable to
> other flat-bottomed designs where the owners are annoyed by wave
> noise. The BW 2 plans show this pad as five layers of 1/2" plywood,
> apparently with substantial epoxy putty to fair it. My version uses
> four layers of 3/4" lumber. I carved it to shape and so needed very
> little putty to fair it. I selected solid wood rather than plywood
> for ease of shaping with edged tools. There is about a 1/8" fillet
> where the bottom course meets the bottom.
>
> The BW2 plans show contours for the ply layers. I had to interpolate
> for thicker stock. I knocked the corners off the courses on the table
> saw before guing it up, but still, carving this with hand tools was a
> good workout. I used jack planes mostly. Rough stock removal was
> with a plane that had the blade ground slightly convex. It was
> finished up with a block plane and relatively little sanding. After
> the epoxy filling, it got a covering of dynel, two layers on the front
> half.
>
> Mine is 65" long and from chine to chine at the forward end. The hump
> is biased forward of the mid point. I suspect this could be adapted
> to any hull by drawing contour lines by eye and shaping. If you have
> built any models by the lift method, you've got the idea.
>
> Doug
Doug:
That's an impressive piece of sculpture. Great work. When you get it
launched, please give a progress report to those of us who have
gone "slap-happy" in flat-bottomed boats.
Gary Blankenship
That's an impressive piece of sculpture. Great work. When you get it
launched, please give a progress report to those of us who have
gone "slap-happy" in flat-bottomed boats.
Gary Blankenship
> > New photos in Bolger 5 under "Anti-slap Pad"...The pictures show a very neat job of building. Although I'm sure it
will quite the bow somewhat, I wonder if, overall, it might not be
just as easy to build a v-bottom boat in the first place. Or, one that
is v-eed only in the bow.
Peter
I have adapted a 7" backer to my 4.5" Dewalt high speed grinder. You
have to have a good hold on it when you turn it on, but you (I) can
carve a stack of plywood to a bevel pretty quick with a course
sanding disk. If you do this, please be careful but it is handy for
bolgering. Clyde
oarmandt wrote:
have to have a good hold on it when you turn it on, but you (I) can
carve a stack of plywood to a bevel pretty quick with a course
sanding disk. If you do this, please be careful but it is handy for
bolgering. Clyde
oarmandt wrote:
> New photos in Bolger 5 under "Anti-slap Pad" show the quieting pad on
> the bow of my Birdwatcher. I thought that this would be adaptable to
New photos in Bolger 5 under "Anti-slap Pad" show the quieting pad on
the bow of my Birdwatcher. I thought that this would be adaptable to
other flat-bottomed designs where the owners are annoyed by wave
noise. The BW 2 plans show this pad as five layers of 1/2" plywood,
apparently with substantial epoxy putty to fair it. My version uses
four layers of 3/4" lumber. I carved it to shape and so needed very
little putty to fair it. I selected solid wood rather than plywood
for ease of shaping with edged tools. There is about a 1/8" fillet
where the bottom course meets the bottom.
The BW2 plans show contours for the ply layers. I had to interpolate
for thicker stock. I knocked the corners off the courses on the table
saw before guing it up, but still, carving this with hand tools was a
good workout. I used jack planes mostly. Rough stock removal was
with a plane that had the blade ground slightly convex. It was
finished up with a block plane and relatively little sanding. After
the epoxy filling, it got a covering of dynel, two layers on the front
half.
Mine is 65" long and from chine to chine at the forward end. The hump
is biased forward of the mid point. I suspect this could be adapted
to any hull by drawing contour lines by eye and shaping. If you have
built any models by the lift method, you've got the idea.
Doug
the bow of my Birdwatcher. I thought that this would be adaptable to
other flat-bottomed designs where the owners are annoyed by wave
noise. The BW 2 plans show this pad as five layers of 1/2" plywood,
apparently with substantial epoxy putty to fair it. My version uses
four layers of 3/4" lumber. I carved it to shape and so needed very
little putty to fair it. I selected solid wood rather than plywood
for ease of shaping with edged tools. There is about a 1/8" fillet
where the bottom course meets the bottom.
The BW2 plans show contours for the ply layers. I had to interpolate
for thicker stock. I knocked the corners off the courses on the table
saw before guing it up, but still, carving this with hand tools was a
good workout. I used jack planes mostly. Rough stock removal was
with a plane that had the blade ground slightly convex. It was
finished up with a block plane and relatively little sanding. After
the epoxy filling, it got a covering of dynel, two layers on the front
half.
Mine is 65" long and from chine to chine at the forward end. The hump
is biased forward of the mid point. I suspect this could be adapted
to any hull by drawing contour lines by eye and shaping. If you have
built any models by the lift method, you've got the idea.
Doug