"Martin Baxter" wrote in message
...
Gregory Hall wrote:
wrote in message
...
On Feb 24, 12:09 pm, "Gregory Hall" wrote:
... I think GRP includes carbon fiber unless you don't add any resin to
the
carbon fiber cloth, that is. Doh! ...
"Doh"?

GRP = Glass Reinforced Plastic.

FRP = Fiber Reinforced Plastic.

Carbon is fiber but carbon is not glass...

-- Tom.

Did you ever hear of FRP? It just so happens that FRP and GRP are used
pretty much interchangeably.

Fiber reinforced plastic definitely includes carbon fiber just as it
includes glass fiber.

Very good Greg, you are learning. Now go back and read Neal's original
post, he specifically stated "GRP", as you seem to have learned, the "G"
stands for GLASS, not carbon.

Cheers
Marty

Picky, picky, picky! But, technically you win.

Greg

Gregory Hall wrote:

Picky, picky, picky! But, technically you win.

Yeah I know, but thanks. You're a bigger man than Wilbur\Kneal\Crapton......


Cheers
Marty

wrote:.
Yes it is. What I have used is 0.185" thick Meranti plywood.

Once the layouts have been done and the parts all cut out and labelled.

A coat of two parts epoxy is applied on each part individually and allows to
dry. Then the parts are assembled (dry) according to the drawing using the
stitching method. Afterward, the assembly is validated and corrected, as
needed it. After that, the epoxy fillets are applied with fibreglass tape
and let to dry.

Subsequently, a second coat to of two parts epoxy is applied inside out.
Before painting (for UV protection), a third and fourth coasts of epoxy is
applied. As you can see, the construction is light and strong. The
hardwood gunwales and keel also add to the stiffness of the boat

No cloth layed over the panels, just at the seams? Seems like a waste
of resin, if you were going to put on two coats you might as well have
put on some cloth which would improve strength & abrasion resistance.

Foam core would have been lighter & stronger; I've seen a number of
tenders & dinghies built using 4mm and 5mm plywood and that's what
convinced me to use foam core.... those boats you have to step very
carefully in & out of.

Fresh Breezes- Doug King

wrote in message
...
wrote:.
Yes it is. What I have used is 0.185" thick Meranti plywood.

Once the layouts have been done and the parts all cut out and labelled.

A coat of two parts epoxy is applied on each part individually and allows
to
dry. Then the parts are assembled (dry) according to the drawing using
the
stitching method. Afterward, the assembly is validated and corrected, as
needed it. After that, the epoxy fillets are applied with fibreglass
tape
and let to dry.

Subsequently, a second coat to of two parts epoxy is applied inside out.
Before painting (for UV protection), a third and fourth coasts of epoxy
is
applied. As you can see, the construction is light and strong. The
hardwood gunwales and keel also add to the stiffness of the boat

No cloth layed over the panels, just at the seams? Seems like a waste
of resin, if you were going to put on two coats you might as well have
put on some cloth which would improve strength & abrasion resistance.

Foam core would have been lighter & stronger; I've seen a number of
tenders & dinghies built using 4mm and 5mm plywood and that's what
convinced me to use foam core.... those boats you have to step very
carefully in & out of.

Fresh Breezes- Doug King

Good comments,
My email was intended to be a brief description on how its done not a step
by step procedures.
Twelve years ago my daughter build a 11'2" Shellback sailing Dinghy applying
four coats (as I have described) of epoxy (No cloth layed over the panels,
just at the seams) plus coats of UV paint. Since then this sailing dinghy
has been stored outside 12 months a year along the rocky edge of the La
Have river NS behind her property. During the Canadian winter its covered
with show and ice. This sailing dinghy is used about 4 - 5 time every week
during the summer. Kids are often dragging the dinghy on the rocky beach,
So far the only maintenance done was painting it with a good quality latex
outside house paint every 2 to 3 years. A quick survey was done amongst her
friends that have build the same dinghy at the same time using only on coat
of epoxy and storing it outside all year.
The finding revealed that none of these dinghies were in use anymore.
Water, snow, ice, rain and quick freezing temperature and melt down have
caused water infiltration and below freezing temperature causing
delaminating of the material used. So far my daughter's Shellback is
holding up good. Every time I visit her I keep telling her to cover the
boat during the winter.

wrote:
My email was intended to be a brief description on how its done not a step
by step procedures.

Sure... but it's a subject of great interest to many; IMHO the best
production dinghies are far too expensive and still have faults...

Twelve years ago my daughter build a 11'2" Shellback sailing Dinghy applying
four coats (as I have described) of epoxy (No cloth layed over the panels,
just at the seams) plus coats of UV paint. Since then this sailing dinghy
has been stored outside 12 months a year along the rocky edge of the La
Have river NS behind her property. During the Canadian winter its covered
with show and ice. This sailing dinghy is used about 4 - 5 time every week
during the summer. Kids are often dragging the dinghy on the rocky beach,
So far the only maintenance done was painting it with a good quality latex
outside house paint every 2 to 3 years. A quick survey was done amongst her
friends that have build the same dinghy at the same time using only on coat
of epoxy and storing it outside all year.
The finding revealed that none of these dinghies were in use anymore.

So the longevity is about ten years? That's pretty good. Sounds like
you are getting good penetration of the epoxy, plus using good wood. I
have built several epoxy & plywood dinghies, usually using cheap ply
like lauan which lasts only 5 years or less regardless of care. The
ones I built using good marine ply lasted longer plus had a sheath of
fine FG cloth. Several people now are using stuff like Dynel which is
supposed to be more abrasion-resistant.

Epoxy resin is heavy. I've weighed the various components of dinghies
that I've built and usually the resin was at least 25% of the weight,
thus my comment that you might as well have added some cloth over the
panel surfaces. I'm also convinced that any boat which could be layed
out in ply panels & assembled could also be built in foam core at only
slightly greater expense and it would be much lighter & stiffer (not
necessarily stronger but more rigid); with good skills & the right
materials it could also be much stronger without much increase in
weight.

The most recent dinghy that I've built is by far the fanciest and also
by far the best
http://sports.webshots.com/album/82561569ZSrzNA


..... So far my daughter's Shellback is
holding up good. Every time I visit her I keep telling her to cover the
boat during the winter.

Very good idea. I've kept boats inside and still lost them to gradual
water penetration (again mostly using cheap plywood). One of the best,
and one which I will probably build another of using better materials,
is Bolger's Shoebox design. The 1/4" (7.5mm) luaun ply version
weighed about 60lbs (27.3kg) which is too heavy for a small pram; I
think using good marine ply you could shave off maybe 10% of the
weight, but using foam core you could take off 50% or more of the
weight.

The Shellback is also a very nice design. I am thinking of getting the
sailing rig of the Shellback to put on the "Winnie's Perfect Dinghy."
There is also some talk of putting it into production with an option
for a nesting/folding version.

Fresh Breezes- Doug King

wrote:

wrote in message
...

wrote:.

Yes it is. What I have used is 0.185" thick Meranti plywood.

Once the layouts have been done and the parts all cut out and labelled.

A coat of two parts epoxy is applied on each part individually and allows
to
dry. Then the parts are assembled (dry) according to the drawing using
the
stitching method. Afterward, the assembly is validated and corrected, as
needed it. After that, the epoxy fillets are applied with fibreglass
tape
and let to dry.

Subsequently, a second coat to of two parts epoxy is applied inside out.
Before painting (for UV protection), a third and fourth coasts of epoxy
is
applied. As you can see, the construction is light and strong. The
hardwood gunwales and keel also add to the stiffness of the boat

No cloth layed over the panels, just at the seams? Seems like a waste
of resin, if you were going to put on two coats you might as well have
put on some cloth which would improve strength & abrasion resistance.

Foam core would have been lighter & stronger; I've seen a number of
tenders & dinghies built using 4mm and 5mm plywood and that's what
convinced me to use foam core.... those boats you have to step very
carefully in & out of.

Fresh Breezes- Doug King


Good comments,
My email was intended to be a brief description on how its done not a step
by step procedures.
Twelve years ago my daughter build a 11'2" Shellback sailing Dinghy applying
four coats (as I have described) of epoxy (No cloth layed over the panels,
just at the seams) plus coats of UV paint. Since then this sailing dinghy
has been stored outside 12 months a year along the rocky edge of the La
Have river NS behind her property. During the Canadian winter its covered
with show and ice. This sailing dinghy is used about 4 - 5 time every week
during the summer. Kids are often dragging the dinghy on the rocky beach,
So far the only maintenance done was painting it with a good quality latex
outside house paint every 2 to 3 years. A quick survey was done amongst her
friends that have build the same dinghy at the same time using only on coat
of epoxy and storing it outside all year.
The finding revealed that none of these dinghies were in use anymore.
Water, snow, ice, rain and quick freezing temperature and melt down have
caused water infiltration and below freezing temperature causing
delaminating of the material used. So far my daughter's Shellback is
holding up good. Every time I visit her I keep telling her to cover the
boat during the winter.



Would that be this one?
http://www.woodenboat.com/store/nutbacks.htm
Or is it a different design?

"cavelamb himself" wrote in message
...
wrote:

wrote in message
...

wrote:.

Yes it is. What I have used is 0.185" thick Meranti plywood.

Once the layouts have been done and the parts all cut out and labelled.

A coat of two parts epoxy is applied on each part individually and
allows to
dry. Then the parts are assembled (dry) according to the drawing using
the
stitching method. Afterward, the assembly is validated and corrected,
as
needed it. After that, the epoxy fillets are applied with fibreglass
tape
and let to dry.

Subsequently, a second coat to of two parts epoxy is applied inside out.
Before painting (for UV protection), a third and fourth coasts of epoxy
is
applied. As you can see, the construction is light and strong. The
hardwood gunwales and keel also add to the stiffness of the boat

No cloth layed over the panels, just at the seams? Seems like a waste
of resin, if you were going to put on two coats you might as well have
put on some cloth which would improve strength & abrasion resistance.

Foam core would have been lighter & stronger; I've seen a number of
tenders & dinghies built using 4mm and 5mm plywood and that's what
convinced me to use foam core.... those boats you have to step very
carefully in & out of.

Fresh Breezes- Doug King


Good comments,
My email was intended to be a brief description on how its done not a
step by step procedures.
Twelve years ago my daughter build a 11'2" Shellback sailing Dinghy
applying four coats (as I have described) of epoxy (No cloth layed over
the panels, just at the seams) plus coats of UV paint. Since then this
sailing dinghy has been stored outside 12 months a year along the rocky
edge of the La Have river NS behind her property. During the Canadian
winter its covered with show and ice. This sailing dinghy is used about
4 - 5 time every week during the summer. Kids are often dragging the
dinghy on the rocky beach, So far the only maintenance done was painting
it with a good quality latex outside house paint every 2 to 3 years. A
quick survey was done amongst her friends that have build the same dinghy
at the same time using only on coat of epoxy and storing it outside all
year.
The finding revealed that none of these dinghies were in use anymore.
Water, snow, ice, rain and quick freezing temperature and melt down have
caused water infiltration and below freezing temperature causing
delaminating of the material used. So far my daughter's Shellback is
holding up good. Every time I visit her I keep telling her to cover the
boat during the winter.

Would that be this one?
http://www.woodenboat.com/store/nutbacks.htm
Or is it a different design?

Yes, the design is from the book "How to build the Shellback Dinghy" by Eric
Dow.
The boat and sail are exactly the same configuration as shown on the book's
cover.

wrote:

Good comments,
My email was intended to be a brief description on how its done not a
step by step procedures.
Twelve years ago my daughter build a 11'2" Shellback sailing Dinghy
applying four coats (as I have described) of epoxy (No cloth layed over
the panels, just at the seams) plus coats of UV paint. Since then this
sailing dinghy has been stored outside 12 months a year along the rocky
edge of the La Have river NS behind her property. During the Canadian
winter its covered with show and ice. This sailing dinghy is used about
4 - 5 time every week during the summer. Kids are often dragging the
dinghy on the rocky beach, So far the only maintenance done was painting
it with a good quality latex outside house paint every 2 to 3 years. A
quick survey was done amongst her friends that have build the same dinghy
at the same time using only on coat of epoxy and storing it outside all
year.
The finding revealed that none of these dinghies were in use anymore.
Water, snow, ice, rain and quick freezing temperature and melt down have
caused water infiltration and below freezing temperature causing
delaminating of the material used. So far my daughter's Shellback is
holding up good. Every time I visit her I keep telling her to cover the
boat during the winter.

Would that be this one?
http://www.woodenboat.com/store/nutbacks.htm
Or is it a different design?


Yes, the design is from the book "How to build the Shellback Dinghy" by Eric
Dow.
The boat and sail are exactly the same configuration as shown on the book's
cover.




That's a sweet looking little boat.

While a bit more involved to build than a plywood pram type, it would be
something to be proud of when finished.

Certainly has a chance as the one...

Thanks

Richard