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Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Wed Nov 14, 2018 4:47 pm
by Christer
Right, so I've been trying to research Ken Hankinson's Wild/Bear Cats, and things don't bode well for building any of them. There are a number of issues with both plans, building and the finished products.

As a member of the WoodenBoat forums so eloquently put it in this thread, http://forum.woodenboat.com/showthread. ... dcat-Cuddy
the plans are pathetic
asthetically ugly
with that useless tug boat style gunwhale (changed)
designed for old style plystringer construction not stitch and glue
needed considerable changes
taking away useless bits and reinforcing oterareas like transom transom knees ect

when you get all the frames up and stuck together and try to skin the hull with plyyou find that you cannot bend the ply fairly around the frames and end up with a great disaster requiring the crudest nastiest dirtiest boatbuilding tofair the 2 inch dips between frames
He goes further:
the hulls on the wildcat i think are too narrow and need to be somewhat wider -the tunnel needs to be higheras it rubs the water at anyspeed - lotsof wetted surface

mounting the engines is difficult requiring alot of thought
There is also a BearCat built by Andy Smith Boatworks in the Philippines, which at least was on the water some years back.

This picture shows the waterline; the white is obviously below the waterline. Notice how short/low the sponsons are.

Image

Here it is on the water:

Image

And finally one showing the stern:

Image

There is next to no clearance between the tunnel ceiling and the water, which I suspect will cause wave slamming at any speed and at any sea conditions with the possible exception of glassy water.

There was a question on the Glen-L forums about whether the height of the sponsons could be increased to reduce the wave slamming, and the answer was "We do not recommend increasing the height of the sponsons." In other words, the boat will not be pleasant to drive.

So that leaves only one real alternative, the bateau.com CT22, which I want to tweak in ways it can't. What to do, what to do...

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Wed Nov 14, 2018 7:46 pm
by Christer
There's a new contender, Schionning Marine's Prowler VT650:

Image

Fantastic looking boat, and suits my program perfectly. I guess the CT22 could be built to look similar to the VT650...

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Wed Nov 14, 2018 9:15 pm
by fallguy1000
Christer wrote: Wed Nov 14, 2018 7:46 pm There's a new contender, Schionning Marine's Prowler VT650:

Image

Fantastic looking boat, and suits my program perfectly. I guess the CT22 could be built to look similar to the VT650...
There is a lot to like about a kit boat.

Fast build.

The only thing I don't like is there ain't much beam and that means you have a 9' limit on the sea. But you don't likely want to be out in anything bigger than 4' in a small boat anyhow.

Costs will be higher. But the design has some provimg done.

Still open, though.

Ask the designer to critique the boat and see what he says.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 5:14 am
by Christer
fallguy1000 wrote: Wed Nov 14, 2018 9:15 pm
Christer wrote: Wed Nov 14, 2018 7:46 pm There's a new contender, Schionning Marine's Prowler VT650:

Image

Fantastic looking boat, and suits my program perfectly. I guess the CT22 could be built to look similar to the VT650...
There is a lot to like about a kit boat.

Fast build.

The only thing I don't like is there ain't much beam and that means you have a 9' limit on the sea. But you don't likely want to be out in anything bigger than 4' in a small boat anyhow.

Costs will be higher. But the design has some provimg done.

Still open, though.

Ask the designer to critique the boat and see what he says.
The boat is designed to be built from foam cored fibreglass composite panels, like the Bateau designs. He specifies Divinycell H80 foam and S-glass for the scantlings, which makes for a very light and strong boat, although an expensive build. Also, the plans are more than AUD3000 alone, so while I like the looks of it, I have to get something that can be built from locally sourced marine plywood.

I would also like 3 ft more length and 1.5ft wider boat for a 7.6x3m or 25x9.75ft beam, to get a little more room inside. We likely won't be out in anything more than 1-2' chops voluntarily, but it would be good to know that the boat can handle 6-8' seas and get us back to shore without falling apart.

It's a partially open boat :) The targa arch makes it easy to attach a button-up roof over the cabin and aft cockpit, and depending on how the soft roof is made, it could be possible to heat it somewhat. I think that arrangement works well enough, and also allows for a head to be installed. An enclosed pilothouse works even better, but I've come to the realization that it requires a much bigger boat, at least 28ft and over, in order to be actually useful and not feel cramped. A dual console with a button-on top and a front door to keep the weather out I think would work well enough.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 7:25 am
by piperdown
Christer wrote: Thu Nov 15, 2018 5:14 am
fallguy1000 wrote: Wed Nov 14, 2018 9:15 pm
Christer wrote: Wed Nov 14, 2018 7:46 pm There's a new contender, Schionning Marine's Prowler VT650:

Image

Fantastic looking boat, and suits my program perfectly. I guess the CT22 could be built to look similar to the VT650...
There is a lot to like about a kit boat.

Fast build.

The only thing I don't like is there ain't much beam and that means you have a 9' limit on the sea. But you don't likely want to be out in anything bigger than 4' in a small boat anyhow.

Costs will be higher. But the design has some provimg done.

Still open, though.

Ask the designer to critique the boat and see what he says.
The boat is designed to be built from foam cored fibreglass composite panels, like the Bateau designs. He specifies Divinycell H80 foam and S-glass for the scantlings, which makes for a very light and strong boat, although an expensive build. Also, the plans are more than AUD3000 alone, so while I like the looks of it, I have to get something that can be built from locally sourced marine plywood.

I would also like 3 ft more length and 1.5ft wider boat for a 7.6x3m or 25x9.75ft beam, to get a little more room inside. We likely won't be out in anything more than 1-2' chops voluntarily, but it would be good to know that the boat can handle 6-8' seas and get us back to shore without falling apart.

It's a partially open boat :) The targa arch makes it easy to attach a button-up roof over the cabin and aft cockpit, and depending on how the soft roof is made, it could be possible to heat it somewhat. I think that arrangement works well enough, and also allows for a head to be installed. An enclosed pilothouse works even better, but I've come to the realization that it requires a much bigger boat, at least 28ft and over, in order to be actually useful and not feel cramped. A dual console with a button-on top and a front door to keep the weather out I think would work well enough.
There's also, according to the website, a cuddy cabin version.
Why not just ask them if it can be scaled by 10%?
The website, at least on the information page, calls for "Built from balsa-core Duflex panels". While I've heard of lots of boats built from balsa I'd be very hesitant to use it. One tiny flaw or nick in the glass and the balsa would be pulling in water like crazy.
I don't have experience with balsa cored boats, only what I've read. However, I've used balsa for other hobby projects and it absorbs water, paint and other liquids more than soft pine.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 8:42 am
by Christer
piperdown wrote: Thu Nov 15, 2018 7:25 am
Christer wrote: Thu Nov 15, 2018 5:14 am The boat is designed to be built from foam cored fibreglass composite panels, like the Bateau designs. He specifies Divinycell H80 foam and S-glass for the scantlings, which makes for a very light and strong boat, although an expensive build. Also, the plans are more than AUD3000 alone, so while I like the looks of it, I have to get something that can be built from locally sourced marine plywood.

I would also like 3 ft more length and 1.5ft wider boat for a 7.6x3m or 25x9.75ft beam, to get a little more room inside. We likely won't be out in anything more than 1-2' chops voluntarily, but it would be good to know that the boat can handle 6-8' seas and get us back to shore without falling apart.

It's a partially open boat :) The targa arch makes it easy to attach a button-up roof over the cabin and aft cockpit, and depending on how the soft roof is made, it could be possible to heat it somewhat. I think that arrangement works well enough, and also allows for a head to be installed. An enclosed pilothouse works even better, but I've come to the realization that it requires a much bigger boat, at least 28ft and over, in order to be actually useful and not feel cramped. A dual console with a button-on top and a front door to keep the weather out I think would work well enough.
There's also, according to the website, a cuddy cabin version.
Why not just ask them if it can be scaled by 10%?
The website, at least on the information page, calls for "Built from balsa-core Duflex panels". While I've heard of lots of boats built from balsa I'd be very hesitant to use it. One tiny flaw or nick in the glass and the balsa would be pulling in water like crazy.
I don't have experience with balsa cored boats, only what I've read. However, I've used balsa for other hobby projects and it absorbs water, paint and other liquids more than soft pine.
I looked at the cuddy cabin version, but no matter how hard I try, I just can't like it.

I thought I remembered it called for balsa cored Duflex panels, but the PDF study plans list Divinycell foam and fibreglass. Also, it was late and so I got confused and thought it was another design I looked at...

I've heard the same about balsa - nice and lightweight, but wicks water like a sponge and isn't really suitable for use in boats. I think that Divinycell is a better choice.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 1:54 pm
by jacquesmm
More questions came by email but I want to reply on the forum. Discussions on the forum will help hundreds of readers.

Christers asked about elimination or reducing the size of a cross beam in order to add bow rider style seating forward of the console as in the Hankinson design.
It is not possible.
One of the big differences between the Hankinson and the CT22 is the height of the deck between the hulls (bridge deck). His deck is very low. This provides volume to have a cockpit forward with seating and an enclosed head. That low clearance produces bad slamming under the deck. It can be acceptable for a protected waters boat used with the same program than a pontoon boat. It is unsafe offshore. You can see that very low clearance in the pictures posted above in this thread.
The CT22 has much more bridge deck clearance but it does not leave enough volume to have such a cockpit.
Look at the perspective drawings:
Image
See the box just in front of the console. That is the cross beam we are discussing, the one with a lid.
In the front, the height inside that box is about 6" above the bridge deck!!!
There is no way to bring that down or eliminate it.
Look at the hatches in the foredeck. Those compartments are 17" deep stern side and 10" bow side. That does not leave enough room for seats.

The choice is simple: have a low bridge deck (Hankinson) and lots of comfort but pay a price in blue water ability or have a seaworthy high bridge deck but no extra room for seating.
Anyway, I would never want to sit there in a formed sea, you"ll fly over board.

Seaworthiness or comfort.
That are your choices. It is not an unusual choice, compromises are a major factor in boat design.
The Hankinson and my CT22 are each good designs but for a different program.

The VT650 is another compromise. From what I see, the freeboard is higher, the windage is more than what I like. The bridge deck is lower but not as low as theWild Cat.
That compromise produces enough volume for the bow rider seating but there will be some slamming. Less than with the Wild Cat, more than the CT22.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 6:03 pm
by fallguy1000
jacquesmm wrote: Thu Nov 15, 2018 1:54 pm More questions came by email but I want to reply on the forum. Discussions on the forum will help hundreds of readers.

Christers asked about elimination or reducing the size of a cross beam in order to add bow rider style seating forward of the console as in the Hankinson design.
It is not possible.
One of the big differences between the Hankinson and the CT22 is the height of the deck between the hulls (bridge deck). His deck is very low. This provides volume to have a cockpit forward with seating and an enclosed head. That low clearance produces bad slamming under the deck. It can be acceptable for a protected waters boat used with the same program than a pontoon boat. It is unsafe offshore. You can see that very low clearance in the pictures posted above in this thread.
The CT22 has much more bridge deck clearance but it does not leave enough volume to have such a cockpit.
Look at the perspective drawings:
Image
See the box just in front of the console. That is the cross beam we are discussing, the one with a lid.
In the front, the height inside that box is about 6" above the bridge deck!!!
There is no way to bring that down or eliminate it.
Look at the hatches in the foredeck. Those compartments are 17" deep stern side and 10" bow side. That does not leave enough room for seats.

The choice is simple: have a low bridge deck (Hankinson) and lots of comfort but pay a price in blue water ability or have a seaworthy high bridge deck but no extra room for seating.
Anyway, I would never want to sit there in a formed sea, you"ll fly over board.

Seaworthiness or comfort.
That are your choices. It is not an unusual choice, compromises are a major factor in boat design.
The Hankinson and my CT22 are each good designs but for a different program.

The VT650 is another compromise. From what I see, the freeboard is higher, the windage is more than what I like. The bridge deck is lower but not as low as theWild Cat.
That compromise produces enough volume for the bow rider seating but there will be some slamming. Less than with the Wild Cat, more than the CT22.
Great reply.

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 8:18 pm
by fallguy1000
Here is a boat that is interesting. Not sure I get the bottom design.

http://www.spirainternational.com/study/ValdezStudy.pdf

Re: Christer's planning-to-build-a boat-at-some-point thread

Posted: Thu Nov 15, 2018 9:41 pm
by cracked_ribs
That guy's stuff always looks really heavily framed to me, although some of his designs have pretty nice lines.