Conchfish AL 17.6T build

[m32825]

Hi guys, first post!

I live in Central Florida and like to fish the inshore areas along our east and west coasts. I'm in the early stages of building a technical poling skiff called a Conchfish. It's built for shallow water fishing, has a tunnel and should be able to run in a few inches of water over hard bottom.

Chris Morejohn designed the hulls of many of the most popular poling skiffs of the last few decades, the Conchfish incorporates his most recent refinements. He is out of the commercial boat building gig, but made non-alloy plans available for diy types a few years ago. I was tempted but ultimately decided to pass because of the chemicals and finishing required. At the beginning of this year he released an aluminum adaptation. I worked with the plan guy to design in a tunnel and make a few other changes, sold my boat, and started learning about aluminum boat building.

I have some experience with aluminum TIG and MIG, but not a lot. I'm still in the early stages, waiting on aluminum. I read through Pollard's "Boatbuilding with Aluminum" then started web surfing, which led me to this forum.

Here's a link with pictures to give you an idea of what I'm trying to build:

    Aluminum Conchfish

Learning a lot looking through old posts. Hopefully some here will find my antics entertaining!    

    -- Carl
 
 
 

[gandrfab]

Looks like fun. 
 https://www.microskiff.com/threads/new- ... st-1049080

Is this a build of the hull you are interested in?

0.jpg (47.96 KiB) Viewed 28811 times

 
 

[m32825]

>Is this a build of the hull you are interested in?

Yes indeed. Matt Phillips is paving the way with the first aluminum hull, he's got it floating. He and his buddy are interested in low rate commercial production. Mine will be the first with a tunnel (assuming no one else beats me to it). I just want one, the better to chase fish with in retirement.

-- Carl

[m32825]

Got my aluminum today! This one gets built upside down, working on a table to put the deck at about 30" or so.

    -- Carl​​​​​​

[gandrfab]

 

[welder]

NICE, keep the pics coming.

[m32825]

Let's try this photo thing. Here's my aluminum.

    -- Carl

IMG_20230810_175100451_HDR_copy_1200x1594_1.jpg (38.34 KiB) Viewed 28701 times

 
 
 

[m32825]

Got the build table together. This one gets built upside down. Deck is on the table, starting to cut and place support channel.

-- Carl

IMG_20230813_000011919_copy_1200x1594_1.jpg (46.46 KiB) Viewed 28700 times

 

[gandrfab]

 
 
 

[welder]

this is going to be fun, nice shop.

 
 
 

[m32825]

>this is going to be fun, nice shop

Thanks, the secret is to build it big enough that you can pile all your stuff into one side and take a picture of the other side that looks relatively uncluttered before it buries you in an avalanche...

[welder]

I like the way you think.

[m32825]

Doubled up some of the front deck support channel.

IMG_20230820_170856566_copy_1200x1594.jpg (37.71 KiB) Viewed 28617 times

 
Cut the front and back hatch support frames.

IMG_20230820_170910769_copy_1200x1594.jpg (43.2 KiB) Viewed 28617 times

 

​​​


 
 
 
 
 
 

[welder]

Thanks for the updates, keep them coming, we love pictures.

[m32825]

Work has been cutting into my project time lately, haven't been able to do much more than think about it. One thing I've been mulling over is fastening the deck to the hull. The plans call for nuts and bolts through a bunch of holes around the perimeter of the deck. Using one-sided fasteners like rivets or rivnuts would make rigging and final assembly easier. This is for a saltwater boat and I plan to paint the top of the deck. Thoughts?

-- Carl

[kmorin]

m32,
If you rivet or bolt the deck to the topsides at the shear (?) you'd have to have some flange or guard deck/shear clamp to rivet or bolt too- if I understand the question?  That piece would be welded to the topsides along the shear- so why not skip that pc (shear clamp/rivet flange) and just weld the deck to the topsides?  It is after all a welded boat....

What am I missing?

Cheers,
Kevin Morin
Kenai, AK

[m32825]

Kevin,

The design incorporates a shear flange for deck attachment:

Screenshot_20230909-192125_copy_657x422.png (81.68 KiB) Viewed 28409 times

The height of the hull ranges from 16" at the back to 21" at the front, most of it covered by deck. Not a lot of room to crawl around in for rigging. I don't see taking it off all the time, but it will make the initial rigging and foam easier, and some of the rigging will be incremental as I get experience using it and have time to work on it.

    -- Carl
 

[m32825]

I'm thinking aluminum rivnuts attached to the shear flange with 1/4-20 stainless steel machine screws going into them. Use tefgel on all the fasteners so they can be disassembled at a later date. The deck is going to be painted, so the stainless steel screw heads won't be on bare aluminum. Maybe a non-metallic washer to make a seal between the screw head and deck? Plans call for butyl tape between the deck and the sheer flange to keep water out of the hull.
 

[m32825]

IMG_20240105_224049832_copy_2956x3452.jpg (52.16 KiB) Viewed 21824 times

IMG_20240201_182804926_copy_1280x964.jpg (79.01 KiB) Viewed 21824 times

IMG_20240204_173740707_copy_1200x1594.jpg (44.03 KiB) Viewed 21824 times

IMG_20240204_173752571_copy_1200x1594.jpg (50.46 KiB) Viewed 21824 times

 

[gandrfab]

 

[m32825]

Tombstone looking good, transom assembly attached.

IMG_20240210_105448452_HDR_copy_1200x1594.jpg (34.19 KiB) Viewed 21790 times

 

IMG_20240210_141223627_copy_1200x1594.jpg (42.84 KiB) Viewed 21790 times

 
 

[m32825]

First pair of panels tacked starting at the transom, nice alignment at the bow.
​​​​​

IMG_20240211_201747700_HDR_copy_1200x1594.jpg (31.98 KiB) Viewed 21772 times

 

[m32825]

Next pair of hull panels tacked in place.

IMG_20240213_133547581_HDR_copy_1200x1594.jpg (40.59 KiB) Viewed 21747 times

 

[gandrfab]

If we had a like button I'd hit it.


 

 

[m32825]

New pair of hull panels in place.
​​​​​

IMG_20240214_202801258_HDR_copy_907x1205.jpg (33.07 KiB) Viewed 21645 times

​​
View from the back.
 

IMG_20240214_203342700_copy_796x600.jpg (96.32 KiB) Viewed 21645 times