Narrowing Beam on XF20

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Stein
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Narrowing Beam on XF20

Post by Stein »

I've been researching a lot of options for a boat for my lake house in Arkansas. I'm near the White River which is an excellent trout river. It is very shallow when generation is low so I'm looking for a shallow draft boat to build. Pretty much everyone down there has a Shawnee or Supreme river boat which is a 20' fiberglass Jon boat.

I'm going to build a Barrelback 19 Chris Craft copy for my retirement boat for Bull Shoals lake so this is my practice wood and epoxy boat to work on technique.

As I want to build a tunnel hull boat with a jet outboard the XF20 seems the logical choice but it's just huge at 8' beam. I've considered the Sabine from Spira which is 19' with a 6'4" beam but it is a flat bottom and is very heavy. He designs more for construction lumber boats so it's 2x4's and ACX plywood and glassed on the outside only.

I want a minimalist boat and even with the large size of the XF20 it's coming in at under 500 lbs. The Sabine is 750. Spira also has the Bayou Jubilee which is 18' and 4'6" beam which is closer to the boats they normally run here and it's about 450 lbs but I want the extra 2' of length for fishing three people.

I'm planning on a small jet outboad - 25-40hp depending on what I can find in a two stroke. Seems all now are 4 stroke and too heavy for me. I'm not looking for speed. I want shallow draft running up river to get back to the boat ramp.

So the long road to a short question is, what's the best way to narrow an XF20 to a max 7' beam? Take a foot out of all frame measurements? take a foot out of the wide section and smooth it fore and aft and maybe 6" out of the rest of the boat?



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topwater
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Re: Narrowing Beam on XF20

Post by topwater »

Take a look at the GF 18 it has 7' 1" beam , pretty much what you are looking for.
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Re: Narrowing Beam on XF20

Post by Jeff »

Stein, Topwater is correct in that the GF18 may be a better choice for you. Let's wait and give Jacques (designer) a little time to respond to your initial question. He is on the West Coast (FL) due to Hurricane Matthew with limited access to his internet. He will be back up and running soon!! Sorry to delay in respondibg, Jeff

Stein
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Re: Narrowing Beam on XF20

Post by Stein »

I looked at the GF18 but I really want the extra two feet in length and the jet outboard tunnel.

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Re: Narrowing Beam on XF20

Post by Jeff »

Stein, got it!! I have noted your question and will ensure Jacques gets back to you!! Jeff

Stein
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Re: Narrowing Beam on XF20

Post by Stein »

Looking at both again it might be easier to just add one frame for additional length on the GF18. I think I have read some threads here where the designer sometimes will throw in the tunnel diagrams on the GF18. I haven't written of the Sabine but it's a heavy boat when it doesn't need to be.

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Re: Narrowing Beam on XF20

Post by topwater »

The tunnel on the XF 20 is for a prop , much to big for a jet. That's why i suggested the GF 18 ,you're
going to have to build your own jet tunnel anyway. Go to jetoutboards.com there is alot of info there
on how and what size of tunnel to build. Outboard tunnels and jet tunnels are two different animals
but jet tunnels are smaller and easier to build.
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Stein
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Re: Narrowing Beam on XF20

Post by Stein »

I was looking at the Flats Stalker 18 last night. Built with the low shear option it is a good looking boat and works well with a small motor. Might see about stretching it 2 feet.

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Re: Narrowing Beam on XF20

Post by jacquesmm »

The Flats Stalker is very narrow and your OP said you wanted beam.
The GF18 as designed but with an outboard jet would be perfect. It is very roomy, no need to lengthen her.
If you ask for it, I give the XF20 tunnel plans with the GF18 but what are you going to gain? 2" underway.
The shallow draft of the XF20 comes form the larger waterplane. Reduce the beam and you reduce the waterplane which increase draft.
There is also a rpcie to pay in performance for a tunnel. You can do it, I would not.

And I agree about the Spira boats being 2x4 monsters: heavy and much more difficult to built than my designs.
Jacques Mertens - Designer
http://boatbuildercentral.com

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Re: Narrowing Beam on XF20

Post by Stein »

I purchased plans for the XF20 the other day. Structurally can Frame C be used for construction purposes as a jig only and then removed from the finished boat? I am planning on decking from Frame B forward.

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