Re: Cartopper: Centreboard case and hull sheath, advice please?
I read Jamie's comments with interest. The cartopper case is pretty
small stiff so I haven't used any screws at all on the centreboard case
or its fixing. Epoxy should be enough given the surface areas being
glued. When I glued it in only minimal clamping was required to keep
it in place while the epoxy hardened.
Andrew
small stiff so I haven't used any screws at all on the centreboard case
or its fixing. Epoxy should be enough given the surface areas being
glued. When I glued it in only minimal clamping was required to keep
it in place while the epoxy hardened.
Andrew
I read Jamie's comments with interest. The cartopper case is pretty
small stiff so I haven't used any screws at all on the centreboard case
or its fixing. Epoxy should be enough given the surface areas being
glued. When I glued it in only minimal clamping was required to keep
it in place while the epoxy hardened.
Andrew
small stiff so I haven't used any screws at all on the centreboard case
or its fixing. Epoxy should be enough given the surface areas being
glued. When I glued it in only minimal clamping was required to keep
it in place while the epoxy hardened.
Andrew
Hi,
I am only a few steps ahead of you in constructing my cartopper. I
should be putting some paint on the inside tomorrow.
Before assembling the centreboard case I got a scrap of kitchen
benchtop laminate from a kitchen manufacturer for free and glued it
onto the inside of the faces of the case where it would be rubbing
against the board. I used thickened epoxy to glue and a hacksaw to
cut and trim the laminate. It wasn't pretty but I will never see it
again.
for the centreboard case i attached two "logs" to the outside lower
edges of the case (70x19mm dressed hardwood from Bunnings hardware).
The bottom edge of these two pieces were cut/planed to be the same
shape as the bottom of the boat and the bottom of the centreboard
casing.
These logs were glued to the case sides with thickened epoxy.
Then the whole assembly was trial fitted on the inside of the floor
(no slot cut at this stage). I found that things weren't quite
square and there were some gaps under the logs at some points. I
planed the bottom of the case and the logs until the fit was pretty
good all along and then I glued it in place with thickened epoxy. I
later filletted and fibreglass taped the outside of these joints just
to be sure. The slot was then cut in the bottom from the outside and
a router bit with end guide used to trim up the slot so that it
matched the slot in the case.
On the subject of sheathing - I used Dynel for the first time on this
project. It drinks up heaps of epoxy and is opaque when dry so you
can't see the woodgrain anymore - but it is supposed to be much more
puncture resistant and it is HEAPS easier to use. No glass fibres to
irritate. It stretches this way and that without creasing. I did
the cartopper hull in two lengths joined lengthwise and there were no
creases or stretch marks at all despite the curves and corners around
chines.
Regards,
Andrew
Warrandyte,
Victoria,
Australia
--- Inbolger@yahoogroups.com, "sandersmark42" <sandersmark42@...>
wrote:
I am only a few steps ahead of you in constructing my cartopper. I
should be putting some paint on the inside tomorrow.
Before assembling the centreboard case I got a scrap of kitchen
benchtop laminate from a kitchen manufacturer for free and glued it
onto the inside of the faces of the case where it would be rubbing
against the board. I used thickened epoxy to glue and a hacksaw to
cut and trim the laminate. It wasn't pretty but I will never see it
again.
for the centreboard case i attached two "logs" to the outside lower
edges of the case (70x19mm dressed hardwood from Bunnings hardware).
The bottom edge of these two pieces were cut/planed to be the same
shape as the bottom of the boat and the bottom of the centreboard
casing.
These logs were glued to the case sides with thickened epoxy.
Then the whole assembly was trial fitted on the inside of the floor
(no slot cut at this stage). I found that things weren't quite
square and there were some gaps under the logs at some points. I
planed the bottom of the case and the logs until the fit was pretty
good all along and then I glued it in place with thickened epoxy. I
later filletted and fibreglass taped the outside of these joints just
to be sure. The slot was then cut in the bottom from the outside and
a router bit with end guide used to trim up the slot so that it
matched the slot in the case.
On the subject of sheathing - I used Dynel for the first time on this
project. It drinks up heaps of epoxy and is opaque when dry so you
can't see the woodgrain anymore - but it is supposed to be much more
puncture resistant and it is HEAPS easier to use. No glass fibres to
irritate. It stretches this way and that without creasing. I did
the cartopper hull in two lengths joined lengthwise and there were no
creases or stretch marks at all despite the curves and corners around
chines.
Regards,
Andrew
Warrandyte,
Victoria,
Australia
--- Inbolger@yahoogroups.com, "sandersmark42" <sandersmark42@...>
wrote:
>how I'm going to attach and
> Hi,
>
> I'm building my first boat, a cartopper, and am a bit stuck about
> seal the centreboard case. I've got the hull finished and ready toglass, but Dynamite's book
> seems to be a bit light on the next bit? I suppose this alsoapplies equally well to any other of
> Bolger's small sail craft.cloth I observe that Dynamite
> While I'm on the subject, When I cover the outside of the hull in
> cuts the fibreglass sheath off flush with the top of the hull. Isthere any reason why I don't
> wrap the the fabric over the lip to protect my exposed soft marineply laminated edges, prior
> to sticking on the Gunwhale?
>
> Cheers!
>
> Mark,
>
> Auckland NZ
>
Mark,
I have the plans for Cartopper but haven't built it yet (I've
developed a severe dislike of epoxy). I have installed a centreboard
case in a Chebacco, though, which is built the same way as Cartopper.
Bolger's plans show the the whole case sitting on top of the bottom,
but I didn't follow that. To get a good seal and to prevent the case
getting out of alignment during installation, I made the slot in the
bottom wide enough for both the board and the plywood sides of the
case. The sides and end posts of the case were left long and trimmed
later. The bedlogs along the side of the case landed on the bottom.
To get a good seal on the ends, I rebated them so there was a shelf
that landed on the bottom like the bedlogs, the slot was cut to match
the rebated case. That is, the slot length is NOT as long as the
unrebated case. This gives two surfaces for bedding instead of one,
as well as locking the whole assembly in place. As you're bedding it
in epoxy, it's going to be virtually impossible to have a leak. This
also stops epoxy from squeezing out into the slot where it would have
to be removed.
If you've already made the case as designed however, the above won't
help you, so get the best fit you can between case and bottom, then
clamp it in place, using one or two bar clamps bearing on sticks
across the openings in the top of the case and under the bottom. Get
it perfectly aligned and clamped, then drill through the bottom into
the bedlogs for your screws. Take it apart, bed it in epoxy and put
it back together with glue and screws. Use plenty of thick glue.
I'd have screws every 3", staggered so they don't cause a split in
the bedlogs.
Whether you go with my method or not, the clamps will take the worry
out of the job. Something else to consider is wedging (lightly) the
centreboard case apart from below before drilling for the screws.
The Chebacco case was 4' long and I wanted to be sure the sides
didn't creep in (I did hear of one boat where this happened). The
Cartopper case is much shorter but depending on your bedlog wood it
may still want to bow in. If you're not following my method be sure
to wrap the wedge(s) in wax paper so they don't get glued in place
when the epoxy oozes into the slot.
To seal the plywood edges later I rounded them, painted them with
epoxy then glassed them, going an inch and a half into the case and
the same outside on the bottom. It was difficult to sand the edge of
the glass smooth inside the case after it cured, so wipe away the
excess before it cures if you do this. Wrapping sandpaper around a
stick will allow you to sand inside the case, it's a pain in the butt
but worth the trouble as having glass there will give you a sure
seal. I used six ounce glass which I found will wrap around a
quarter inch radius (not diameter). Lighter glass might bend around
a tighter radius but may be harder to wet out. Cutting the glass on
a bias helps it lie down and stay down.
From this, you may guess that wrapping the glass over the top of the
sides will be difficult. However, your gunwales will be flush with
the top of the sides, so the glassed side will be safely sandwiched
and can't delaminate. Round the inner edge and seal with epoxy
before painting and it should be fine too.
Sorry to be so long-winded!
Jamie,
Victoria BC
--- Inbolger@yahoogroups.com, "sandersmark42" <sandersmark42@...>
wrote:
I have the plans for Cartopper but haven't built it yet (I've
developed a severe dislike of epoxy). I have installed a centreboard
case in a Chebacco, though, which is built the same way as Cartopper.
Bolger's plans show the the whole case sitting on top of the bottom,
but I didn't follow that. To get a good seal and to prevent the case
getting out of alignment during installation, I made the slot in the
bottom wide enough for both the board and the plywood sides of the
case. The sides and end posts of the case were left long and trimmed
later. The bedlogs along the side of the case landed on the bottom.
To get a good seal on the ends, I rebated them so there was a shelf
that landed on the bottom like the bedlogs, the slot was cut to match
the rebated case. That is, the slot length is NOT as long as the
unrebated case. This gives two surfaces for bedding instead of one,
as well as locking the whole assembly in place. As you're bedding it
in epoxy, it's going to be virtually impossible to have a leak. This
also stops epoxy from squeezing out into the slot where it would have
to be removed.
If you've already made the case as designed however, the above won't
help you, so get the best fit you can between case and bottom, then
clamp it in place, using one or two bar clamps bearing on sticks
across the openings in the top of the case and under the bottom. Get
it perfectly aligned and clamped, then drill through the bottom into
the bedlogs for your screws. Take it apart, bed it in epoxy and put
it back together with glue and screws. Use plenty of thick glue.
I'd have screws every 3", staggered so they don't cause a split in
the bedlogs.
Whether you go with my method or not, the clamps will take the worry
out of the job. Something else to consider is wedging (lightly) the
centreboard case apart from below before drilling for the screws.
The Chebacco case was 4' long and I wanted to be sure the sides
didn't creep in (I did hear of one boat where this happened). The
Cartopper case is much shorter but depending on your bedlog wood it
may still want to bow in. If you're not following my method be sure
to wrap the wedge(s) in wax paper so they don't get glued in place
when the epoxy oozes into the slot.
To seal the plywood edges later I rounded them, painted them with
epoxy then glassed them, going an inch and a half into the case and
the same outside on the bottom. It was difficult to sand the edge of
the glass smooth inside the case after it cured, so wipe away the
excess before it cures if you do this. Wrapping sandpaper around a
stick will allow you to sand inside the case, it's a pain in the butt
but worth the trouble as having glass there will give you a sure
seal. I used six ounce glass which I found will wrap around a
quarter inch radius (not diameter). Lighter glass might bend around
a tighter radius but may be harder to wet out. Cutting the glass on
a bias helps it lie down and stay down.
From this, you may guess that wrapping the glass over the top of the
sides will be difficult. However, your gunwales will be flush with
the top of the sides, so the glassed side will be safely sandwiched
and can't delaminate. Round the inner edge and seal with epoxy
before painting and it should be fine too.
Sorry to be so long-winded!
Jamie,
Victoria BC
--- Inbolger@yahoogroups.com, "sandersmark42" <sandersmark42@...>
wrote:
>how I'm going to attach and
> Hi,
>
> I'm building my first boat, a cartopper, and am a bit stuck about
> seal the centreboard case. I've got the hull finished and ready toglass, but Dynamite's book
> seems to be a bit light on the next bit? I suppose this alsoapplies equally well to any other of
> Bolger's small sail craft.cloth I observe that Dynamite
> While I'm on the subject, When I cover the outside of the hull in
> cuts the fibreglass sheath off flush with the top of the hull. Isthere any reason why I don't
> wrap the the fabric over the lip to protect my exposed soft marineply laminated edges, prior
> to sticking on the Gunwhale?
>
> Cheers!
>
> Mark,
>
> Auckland NZ
>
Fiberglas won't wrap an edge like that and look good. I seal the inside
pieces of a centerboard before assembly, use epoxy as the glue and
screws to hold it on.
HJ
sandersmark42 wrote:
pieces of a centerboard before assembly, use epoxy as the glue and
screws to hold it on.
HJ
sandersmark42 wrote:
> Hi,
>
> I'm building my first boat, a cartopper, and am a bit stuck about how I'm going to attach and
> seal the centreboard case. I've got the hull finished and ready to glass, but Dynamite's book
> seems to be a bit light on the next bit? I suppose this also applies equally well to any other of
> Bolger's small sail craft.
> While I'm on the subject, When I cover the outside of the hull in cloth I observe that Dynamite
> cuts the fibreglass sheath off flush with the top of the hull. Is there any reason why I don't
> wrap the the fabric over the lip to protect my exposed soft marine ply laminated edges, prior
> to sticking on the Gunwhale?
>
> Cheers!
>
> Mark,
>
> Auckland NZ
>
>
>
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Hi,
I'm building my first boat, a cartopper, and am a bit stuck about how I'm going to attach and
seal the centreboard case. I've got the hull finished and ready to glass, but Dynamite's book
seems to be a bit light on the next bit? I suppose this also applies equally well to any other of
Bolger's small sail craft.
While I'm on the subject, When I cover the outside of the hull in cloth I observe that Dynamite
cuts the fibreglass sheath off flush with the top of the hull. Is there any reason why I don't
wrap the the fabric over the lip to protect my exposed soft marine ply laminated edges, prior
to sticking on the Gunwhale?
Cheers!
Mark,
Auckland NZ
I'm building my first boat, a cartopper, and am a bit stuck about how I'm going to attach and
seal the centreboard case. I've got the hull finished and ready to glass, but Dynamite's book
seems to be a bit light on the next bit? I suppose this also applies equally well to any other of
Bolger's small sail craft.
While I'm on the subject, When I cover the outside of the hull in cloth I observe that Dynamite
cuts the fibreglass sheath off flush with the top of the hull. Is there any reason why I don't
wrap the the fabric over the lip to protect my exposed soft marine ply laminated edges, prior
to sticking on the Gunwhale?
Cheers!
Mark,
Auckland NZ