Flyfishing kick boat cat

5kg????? You're gonna die of thirst.

 

Restock at lunch time

With the new hull I can pack more stuff!

 

Put vertical bow and stern shapes. That gets more bouyancy for the length.
If you have too much then narrow each hull (much better).

Take a look at your hull shape underwater. It is so close to a round shape you might as well just strip the bottom (only).
If you do, sink the foot about 1 1/2 inches so it will have some longitudinal stability. This was a painfull lesson for me.
If not, be prepared to put a small skeg on the stern, both hulls.

How wide is each individual hull? looks very fat.

 

Well its kind of too late. I cut all the boards. It is fat. I think from a traditional efficient catamaran perspective its very fat but I can't have these really long narrow hulls or it will become too difficult to turn and often one is among small channels and in amongst the lillies and weed beds so I opted for shorter fatter hulls. Anyway whats done is done. Busy epoxy coating the panels already. They are quite small little hulls. I think it will be fine. So long as they are stable buoyant enough. Its really just floating around. There is very little speed involved here!

 

Good luck

 

stitching underway... when I put the top chines on I realised it was too high! So I shaved an inch and a half from the sheer. They look workable. They seem huge on the desk and tiny when I sit between the hulls. I have a feeling I may need to lower the seating position to get the center of gravity down a tad. Just need to skim the water with my butt.

from a construction point of view I can see now where my design was a bit silly... mostly in the second chine where the ends were too curved which made it very hard to get the panels to open up. so I shaved the curves to a much gentler radius and then it all worked fine. All good... learning lots. Enjoyed the process but its murder on hands!

 

Thinking about what you said about the skeg... Are you saying more from a longitudinal tracking stability perspective? otherwise I'm not following 100%. But I am thinking a hardwood strip along the bottom which could be laminated into a skeg could help to strengthen things along the bottom for rocks and just dragging it onto the shore... like skids almost? Thanks!

 

I was saying that if you rounded the bottom, you needed to drop the bow and stern into the water about 1".
If you didn't do that with a round bottom, you might not be able to keep it in a straight line, so then you would need a skeg.

With the shape you have I have no idea if you would need one. Personally I wouldn't put one on unless it showed to be required. And yes I was talking about longitudinal tracking stability.

Skids? Your choice - you know how you will use the boat.

 

Some good progress. I'm not 100% sure what exactly to do moving forward. I've stitched and glued and removed the stitches and half faired the outside of the hulls and put on a coat of white tinted epoxy to help see whats going on with the faring. I'll probably focus on interior seam taping and mechanism for attaching the pontoons to the frame next.

 

Hello... After a rather disappointing epoxy application and just life getting very busy, the project got relegated to the rafters where it has gathered dust. I had come to realize there was way too much boat above the waterline. Initial tests on a windy day has the thing blowing all over the place. Not ideal as wind is no fun in a kick boat.

So it's now mid winter and I choose now to get it down, man up, and just cut roughly 5 inches off the top of the hulls, and soldier on in a more freeform fashion. I did prior to cutting it, do a test with a bunch of exercise weights, 5 liter water bottles, a cooler full of water and a 20 liter bucket. Close enough to 95kg. Then took note of the waterline as a guide to how much to cut off. I also did a in use test and kicked around on it. It felt surprisingly stable and very easy to turn and propel even without flippers so that was very encouraging.

So now it's onto glassing the insides, glueing on the decks, doing some inwales on the middle sections with tie down points, glassing the hulls outsides and figuring out how to attach the seat H frame to the bulkheads and make them a bit stronger. I have some ideas.

Open to any advice... Thanks

 

The rabbit holes we travel down.... My first thought would be to build foam strip hulls and heavily reinforce the keel strip. But with symmetric fore and aft hulls you could could make one half hull mold and cast four bits......
Actually your project looks interesting and doable, the multi chine hulls with drop down ends are a significant improvement over initial design.
Since you are now in construction, peel ply on glass work will simplify your life.

 

Do you belly flop on this thing to propel it?

 

Flippers sitting backwards mostly although a little trolling motor and battery would be more than adequate. But mostly one just slowly kicks around with flippers while fishing. There are many inflatable kick boat/float tube/belly boats out there. I have inflatable ones but you kinda sit half in the water, they are terrible in the wind and bladder punctures or failures can ruin ones day. Also they are slow due to pretty much being a blob in the water . Much more practical for transportation.
My friend has the bigger blue one where you sit quite high. And most of the pontoons stick out the water which makes for a lot of windage.

 

Yes I'm using peel ply now! Did quite a lot of sanding . I have been building up the 4 bulkheads with some fairly heavy cloth and epoxy as they will transfer the weight down to the water. Still not too sure how I'll go about fixing the frame to the hulls just yet. Nor what to build the frame from. I'm wondering if just the glass tape and a coat of epoxy on the insides of the 4 closed sections will be fine



Not too worried about strength. I'm not even sure I need hatches on the 4 closed sections. Perhaps just drain bungs.

 

Well, you did ask for input .. and this is the first time I have seen this posting.

The build will be a considerably different experience compared to a float tube of the type you have pictured. The things that have been listed which are positive with a solid design may be more than offset by the drawbacks, just my humble experience. Over 50 years tinkering with one man fishing craft of just about every sort, kayaks, rafts, s u p's, presently own 15 one man crafts most of which are float tubes of various designs.

The main drawbacks for me as regards the Build would be the weight at least double or more; the lack of built in pockets for storage available with most FT; harder to control because of varying exposure as each separate hull is never identical in water resistance because of weight balance/ currents affecting one pontoon more than the other, shallow water hang ups of one and not another, being trapped by protruding rocks getting caught between the toons; too bulky to easily Portage by using removable back straps to walk around difficult areas, Etc. Fins may not give suitable propulsion Force because considerable appendage drag of legs and fins, usually don't work in shallow water under 1 m and can be dangerous due to possible entanglement with strainers, Etc. The weight with a traditional added motor and Battery may further tax the existing design carrying capacity. One way around the motor weight issue that I use , which also allows for working the flats down to 25 cm is to rig up a drill propeller for propulsion, as Illustrated in this link;



Of course, I don't know what kind of waters you will be visiting or what kind of exploration you will be doing in your Pursuits. So, It's possible my thoughts/ ideas will not be of any use to you, or some others, and can be ignored!