# Building a modified Bateau FS 18 (FS18-ish)



## itchy (Mar 3, 2019)

It didn't take me long to make the project overly complicated:
Rather than cut out the frames from the plans, I transferred drew up the frames and cut them out on a CNC router. The router only has about a 2' x 2' cut volume, so I had to build the frames out of a few different puzzle pieces.


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## itchy (Mar 3, 2019)

Here are all the frames cut out, glued up and attached to the strongback.


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## itchy (Mar 3, 2019)

In the shot above, you can see on frame B where I extended the gunnel location out by about 3". The reason for this is to build in some modest spray rails in an attempt to make the skiff run a little drier.

While this step took a little extra planning and thinking, it didn't add a significant amount of time. The rounded chine option, however, does add more work (cutting, stitching, gluing and most certainly fairing).


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## itchy (Mar 3, 2019)

More build pics, not really in a chronological order but generally all this was about the same time.

Stitched, gaps filled. Seams glassed, then glassed with the wide cloth.

On the transom, you can see the first materials deviation. For the build, I used okume plywood for the panels that would need to bend (be "developable") but for the flat frames I used divinycell. H80 for the interior bulkheads and higher density foam for the transom, transom knees, etc. Going 100% composite isn't recommended by the designer because the need for more layers of glass (to build sufficient impact strength) kills any weight savings found using the foam core in the hull.


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## itchy (Mar 3, 2019)

It takes two seconds to look at these pictures, but the fairing step is definitely very tedious, very labor intensive, and not very photogenic. 

Five plus rounds of fairing, three rounds of System 3 two part primer.


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## itchy (Mar 3, 2019)

Once the hull was primed, we built a cradle, flipped the boat, and put the strongback on casters.

Then, more progress on the inside. Sanding any drips from the stitching process, glassing the inside, glassing in stringers and bulkheads.


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## itchy (Mar 3, 2019)

Once the stringers and bulkheads are in, you get a sense for how strong and stiff the boats built using the stitch and glue method really are. The 18 foot long structure probably weighs less than 140 pounds, but just feels solid.


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## itchy (Mar 3, 2019)

I foamed the cockpit area under the sole as well as the outboard section of the front compartment between the stringers and the hull. There about 900 pounds of positive displacement in there.

Also, you can see the two chase tubes running from the back section to the front hatch...one side for fuel line, one for wiring. Both runs have conduit bends (not sharp 90') so that - hopefully - running lines is painless.


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## itchy (Mar 3, 2019)

For the sole, I used 1" thick nidacore rather than plywood. This approach is lighter and when glassed on both sides, much, much stiffer. I had read other build threads with complaints of soft spots in the sole. I didn't want that to be the case here.

Here I glassed the underside of the nidacore, then bonded that to the sole at the hull edges and along the stringers. Followed that up by glassing the top of the as well as about 4" of hull side.


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## itchy (Mar 3, 2019)

Glassing in the sole. You can see the location for the cockpit drain to the bilge.


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## itchy (Mar 3, 2019)

Even through 1" nidacore and two layers of biax, you can see the stringer grid. (Interestingly, it shows up in pictures more clearly than when you look at it)


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## itchy (Mar 3, 2019)

For the front hatch area, I added some scrap divinycell foam over the flotation foam and glassed it in. Also added some supports for the fuel tank, leaving easy path for water to drain back and plenty of air circulation.


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## MAK (Dec 15, 2017)

Looks like a great build. How far did you get with it and how much are you asking?


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## 17376 (May 5, 2017)

I’m just going to right up front.. this is badass and I am going to copy this.. 

I have built a couple of FS18’s and I just recently built the Conchfish. I will say that the FS18 is a dryer boat than the CF. Now with you adding these spray rails, I can’t imagine how much dryer this will be. It looks awesome!!


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## Guest (Mar 4, 2019)

Very nice!


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## Guest (Mar 4, 2019)

Travis Smith said:


> I’m just going to right up front.. this is badass and I am going to copy this..
> 
> I have built a couple of FS18’s and I just recently built the Conchfish. I will say that the FS18 is a dryer boat than the CF. Now with you adding these spray rails, I can’t imagine how much dryer this will be. It looks awesome!!


I wanna see foam core, carbon innegra/ basalt layup and a vacuum bag this time! I’ll help ya set up a cheap system!


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## 17376 (May 5, 2017)

Boatbrains said:


> I wanna see foam core, carbon innegra/ basalt layup and a vacuum bag this time! I’ll help ya set up a cheap system!


I’m down let me know when!


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## Guest (Mar 4, 2019)

Travis Smith said:


> I’m down let me know when!


As soon as I get some hatches installed in a blue skiff, get X-Caliber in her owners possesion, and get a johnsen skiff stretched 3’ with a cap


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## DuckNut (Apr 3, 2009)

Holy crap, you built a half of a boat in a day.

Great job Itchy.


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## Jred (Sep 22, 2013)

itchy said:


> Glassing in the sole. You can see the location for the cockpit drain to the bilge.


Is that a layer of Lantor Soric between the glass and the nidacore?


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## itchy (Mar 3, 2019)

The green material is high-density foam core (left over material from the transom). I used thickened epoxy to glue it into the honeycomb. Honeycomb core is great, but a PITA if you are planning on cutting or drilling.


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## Tautog166 (Jul 7, 2018)

Would have loved to see you finish this. So nice.


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## TX_Brad (Jun 8, 2018)

itchy said:


> The green material is high-density foam core (left over material from the transom). I used thickened epoxy to glue it into the honeycomb. Honeycomb core is great, but a PITA if you are planning on cutting or drilling.


Any chance you got some finished pictures to share from whomever you sold it to? I’m about to start an FS18 and think this is exactly what I want to do with the Hull.


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