MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
@x42g2000yqx.googlegroups.com, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

On Sat, 25 Sep 2010 12:58:15 -0700 (PDT), Frogwatch
wrote:

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

If this sail boat isn't going to be dragged up on the beach and then
jumped in but is always going to be afloat when supporting a load I
don't see a thing wrong with your plans.

I currently build dinghys about the size of a Mini Cup out of 3 mm ply
sides and bottom. The transom would be 8 mm ply with a doubled where
the engine mount is and a honeycomb seat top bracing it on the inside.
Designed for a 3 HP motor. I do add a 3 mm doubler in the area where
the oar locks are mounted as I am afraid of the sides flexing if
someone puts long oars in it.

I cover the entire outside with the lightest cloth I can locate -
probably about 4 oz. cloth in your numbers. The inside bottom is also
covered, more for a wearing surface.

All joints are faired and taped, as the boats are stitch and glue.

My boats have a small bow seat, more as a structural member then a
seat and a stern seat. Both are topped with honeycomb that I make my
self with 3mm ply skins and core. the center thwart is the same thing,
i.e.. skins and core.

I used to build essentially the same design with 1/4 inch ply but it
was really too heavy for one man to handle without davets, thus the
change to 3 mm.



Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

In article ,
says...

On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...

--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

On Sep 27, 6:58*am, I am Tosk wrote:
In article ,
says...





On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. *#2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. *While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. *Am almost done. *However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. *Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. *Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. *Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. *I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars..
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. *I have devised a much improved gooseneck where
the two spars attach to the mast. *Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...

--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

More thoughts. Bottom would have 8 oz glass for better wear. The
cockpit would be glassed inside with 4 oz. All seams taped with 6 oz
with epoxy filets inside and out.
The center widthwise support made from 2X2" would not be used. It
only serves to stiffen the joint of two sheets and this can be done
with glass. Most of the curve of the bottom would be produced by the
fore and aft cockpit bulkheads. These would all have 3/4 X 3/4"
reinforcing at the edges just as the MiniCup does for ease of screwing
together and to yield a large glue surface. These will all be epoxy
filleted and glassed. My MiniCups made from 3/16" ply have needed
reinforcing across the wide foredeck and aft deck areas so I will
provide this.
The transom of the original MiniCup is very poor and I had to make it
stronger. I will use 1/4" ply glassed on both sides AND the G10
composite to attach the rudder pintles (or are they gudgeons?) to the
transom. The transom will be attached with 20 oz biax to the sides
and bottom.
I do not see how to make this boat as stitch and glue so will simply
update the use of "stringers" as attachments for the sides to the
bottom and deck to sides.

In article 2e2c5957-2511-4c6f-915f-5f32257af937
@n3g2000yqb.googlegroups.com, says...

On Sep 27, 6:58*am, I am Tosk wrote:
In article ,
says...





On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. *#2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. *While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. *Am almost done. *However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. *Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. *Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. *Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. *I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. *I have devised a much improved gooseneck where
the two spars attach to the mast. *Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...

--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

More thoughts. Bottom would have 8 oz glass for better wear. The
cockpit would be glassed inside with 4 oz. All seams taped with 6 oz
with epoxy filets inside and out.
The center widthwise support made from 2X2" would not be used. It
only serves to stiffen the joint of two sheets and this can be done
with glass. Most of the curve of the bottom would be produced by the
fore and aft cockpit bulkheads. These would all have 3/4 X 3/4"
reinforcing at the edges just as the MiniCup does for ease of screwing
together and to yield a large glue surface. These will all be epoxy
filleted and glassed. My MiniCups made from 3/16" ply have needed
reinforcing across the wide foredeck and aft deck areas so I will
provide this.
The transom of the original MiniCup is very poor and I had to make it
stronger. I will use 1/4" ply glassed on both sides AND the G10
composite to attach the rudder pintles (or are they gudgeons?) to the
transom. The transom will be attached with 20 oz biax to the sides
and bottom.
I do not see how to make this boat as stitch and glue so will simply
update the use of "stringers" as attachments for the sides to the
bottom and deck to sides.

Sounds like it should work fine, I have built several hybrids (stitch
and tape/tack and glue/glue and screw) which included several methods of
joinery in one vessel. As to your idea to "have 3/4 X 3/4"
reinforcing at the edges just as the MiniCup does for ease of screwing
together and to yield a large glue surface. These will all be epoxy
filleted and glassed". Why fillet and glass after already putting the
extra 1-1/2" extra glue area with the 3/4 x 3/4 already there? You are
trying to save weight.

And personally, I might still consider 6mm sheets of occume (22 lbs
each, much lighter than standard Marine ply) and lighter glass on the
sides. Glass and Epoxy is pretty heavy too.

The last issue I would address is rot and "encapsulation". I have found
over the years is sealing with glass or epoxy, both sides of a hull
surface. I know I have noted it before and the howls usually follow, but
to me the glass and epoxy will let moisture in, but make it hard for it
to wick out. I prefer epoxy cloth on the outside surfaces or wet
surfaces, and paint (which can breathe) on the inside. Sometimes I will
use a thinned coat of epoxy as a sanding sealer to stand up the grain
and make a nice base for the primer. Still the inside sealer for me is
always paint since years ago when I saw some "encapsulated" boats with
severe rot problems.

Just my opinion.
--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

On Mon, 27 Sep 2010 10:57:13 -0700 (PDT), Frogwatch
wrote:

On Sep 27, 6:58*am, I am Tosk wrote:
In article ,
says...





On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. *#2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. *While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. *Am almost done. *However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. *Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. *Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. *Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. *I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. *I have devised a much improved gooseneck where
the two spars attach to the mast. *Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...

--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...

More thoughts. Bottom would have 8 oz glass for better wear. The
cockpit would be glassed inside with 4 oz. All seams taped with 6 oz
with epoxy filets inside and out.

I'm not sure that is the best solution, although it certainly can be
argued. My own experience is that if one plans on dragging a
fiberglass boat up on beaches it is better to use some form of
sacrificial "wear strips" - perhaps wood laths glued on the bottom to
protect the bottom, although this certainly can be argued.

By the way, I'm sure that you know that 8 oz. cloth actually weighs
approximately twice that figure when installed due to the resin used.

The fillets are there to ensure that the cloth adheres to the complete
joint as glass cloth cannot be bent 90 degrees. So anywhere the cloth
is planned to be applied the surfaces must be a smooth radius. It is
"epoxy filler", by the way :-)

The center widthwise support made from 2X2" would not be used. It
only serves to stiffen the joint of two sheets and this can be done
with glass. Most of the curve of the bottom would be produced by the
fore and aft cockpit bulkheads. These would all have 3/4 X 3/4"
reinforcing at the edges just as the MiniCup does for ease of screwing
together and to yield a large glue surface. These will all be epoxy
filleted and glassed. My MiniCups made from 3/16" ply have needed
reinforcing across the wide foredeck and aft deck areas so I will
provide this.
The transom of the original MiniCup is very poor and I had to make it
stronger. I will use 1/4" ply glassed on both sides AND the G10
composite to attach the rudder pintles (or are they gudgeons?) to the
transom. The transom will be attached with 20 oz biax to the sides
and bottom.
I do not see how to make this boat as stitch and glue so will simply
update the use of "stringers" as attachments for the sides to the
bottom and deck to sides.

I have essentially stopped using fasteners in building small wooden
boats as a properly designed epoxy joint is already stringer then the
parent wood. A thought about the stringers - they might be 3/4 X 3/4
three sided stringers which would give the gluing surfaces and reduce
the requirement of fairing considerably. Epoxy is heavy and the less
one can use the lighter the structure.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

On Mon, 27 Sep 2010 06:58:45 -0400, I am Tosk
wrote:

In article ,
says...

On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...


Agreed that a layer of glass on one side is inferior to glass on both
sides but I would argue that it is far more then simply a sealer. In
fact if it is simply a sealer there would be no sense in applying the
cloth as glass cloth is far from being water proof, quite the contrary
in fact.

If sealing were the sole purpose then all the boat designers wouldn't
be recommending "glass over...." .

The layer of glass actually makes the 3 mm ply substantially more
resistant to bending then bare ply would be. A parallel might be
fabric covered aircraft where the airframe is covered with a cloth
which is perhaps less strong then a bed sheet, which is then
reinforced with coats of cellulose dope.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

In article ,
says...

On Mon, 27 Sep 2010 06:58:45 -0400, I am Tosk
wrote:

In article ,
says...

On Sat, 25 Sep 2010 18:21:02 -0400, I am Tosk
wrote:

In article 084c9f63-3d17-496f-8a21-74c4d53f4a02
, says...

MiniCup #`1 is still sitting on sawhorses while I decide whether or
not to rebuild her. #2 which I have been using developed cracks from
rot in the 3/16" poor quality ply I used on her even though she had
been glassed with 4 oz glass and epoxy. While fixing this I found
more rot so ended up covering her entire rear with another layer of
glass. Am almost done. However, she seems to have absorbed some
water that I cannot get rid of as she seems heavy even with ports cut
in all her spaces.
Am looking over the old MiniCup plans and considering how to design a
modern version that will be much lighter. Considering using 3mm
Okuome Ply covered with 8 oz glass all over with stiffening ribs of
foam and glass. All interior joints would be glass taped and interior
epoxied as well to seal the wood. Transom would be reinforced with
thicker ply and G10 glass composite for the rudder stresses. Cockpit
and mast step would be self bailing and all hardware of either bronze
or SS. Instead of being a "hardware store boat", I'd specify buying
actual boatbuilding screws and pulleys made for boats. I'd reccomend
buying 1/8" Al tubing for the mast and 1/16" for the two other spars.
The sail should be sewn from white polytarp, none of this duct tape
stuff and visqueen. I have devised a much improved gooseneck where
the two spars attach to the mast. Any other ideas?

Sounds to me like you are going to use 1/8 inch ply and glass for
structure.. Glass doesn't add structure really it should be used for
protection if not laminated into a hull... Use 6mm plywood and protect
it with 4 oz tight weave if you need abrasion protection and such...

Err.. why is it that glass over plywood doesn't add structure while
glass cloth over foam does?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Laminated glass might. One layer over a 3mm plywood, not so much... In
most applications for small boats such as this, the glass is more as a
sealer and protection than a structural component. Especially one layer
of 4 oz tight weave...


Agreed that a layer of glass on one side is inferior to glass on both
sides but I would argue that it is far more then simply a sealer.

Not what I said at all, for smaller boats, glass on both sides only
invites more rotting and moisture retention...

In
fact if it is simply a sealer there would be no sense in applying the
cloth as glass cloth is far from being water proof, quite the contrary
in fact.

Of course there would be "sense" in applying the glass. To understand
you must first understand that glass it to hold resin, resin is to fill
glass.. They work together, it's just the way it is...

If sealing were the sole purpose then all the boat designers wouldn't
be recommending "glass over...." .

Sure they would, cause glass it to hold resin...

The layer of glass actually makes the 3 mm ply substantially more
resistant to bending then bare ply would be. A parallel might be
fabric covered aircraft where the airframe is covered with a cloth
which is perhaps less strong then a bed sheet, which is then
reinforced with coats of cellulose dope.

Don't know much about airplanes but I bet the framework is substantial
under that skin. Either way, a 4 oz layer of glass over 6mm Occoume does
not all all that much stiffness. Glass is good for adding structure when
laminated into fillets, but trying to use it to stiffen a plywood hull
is a waste of time and poor design.

The guy who taught me to use glass and resin had over 40 years in the
shop, fabricating with glass, resin, and other combinations of
materials. He knew more than either of the two distributors I bought
from as to be expected as his experience was all hands on in the shop.
Most boat builders I know don't really understand as much about glass
and resin as they think they do, but I know how my ideas are taken here
and not to be an ass, I know how you are about being challenged on such
issues so I will leave this as my last post to this thread..

Take it for what it's worth... I will note that I have built over 50
plywood, glass, and resin, stitch and tape, tack and tape, and glue and
screw type boats in my day...

Cheers to you too
Scotty from SmallBoats.com

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)



--
OH, I could do the 105 footer, but I would hate to waste the last few
seconds of my life with my eyes closed, screaming like a little
girl...