Tandem SOT Build Log: Blue Fin

[scottrunnr]

I spent most of this week finishing off insulating the stern fish storage area. I use the aft storage area basically as a large cooler for what I catch. On hot summer days I had to put 10-15 lbs of ice in there to keep the fish fresh. So I figured a few pounds spent on creating a water-tight insulated area was worth it.

Below are the steps I took. I used pink foam-board insulation with a layer of 1.5mm ply over it to make it water-tight. The seams where fileted and glassed. I did the front & back ends first. Then I worked my way from the bottom left/right sides upwards.

1. Below is the foam-board installed with Liquid Nails to the back of the rear-bulkhead.



2. Below is the 1.5mm Okume ply filleted to the hull and quarter-round over top of the foam-board.



3. I ripped some pine and glued on the hull bottom centerline to provide a glueing/support base for the ply. Then I used liquid nails to put the foam in.



4. I forgot to take more pictures along the way. The finished pictures are below. Basically I used epoxy/wood flour to fillet the bottom panels to the ripped pine at the centerline, to the hull up higher, and to the front/back ends. The centerline seam was glassed. Then I did the next panel up on left/right. Foam in and then ply filleted to the bottom one just installed, the hull higher up, and the ends. The lower side was then glassed at the seam. I repeated this working my way up to the quarter round supports for the deck.

[scottrunnr]

Opps, forgot to include pictures of the stern getting insulated.

[scottrunnr]

Nearing completion!

I tack welded the aft-deck w/accessories and did a final sanding/saturation coat before glassing to the hull. Same with the fore-deck. Also played with the stern. See photos below.


1. Aft-deck saturation coated and glassed.



2. Aft-deck holes cut for hatch, rod holders, safety flag, & carrying handle.



3. All of the above installed in aft-deck.



4. Aft-deck tack-welded to hull.



5. Aft-deck/hull joint sanded and saturation coat applied in preperation for glassing to the hull.



6. Fore-deck/hull joint sanded and saturation coat applied in preperation for glassing to the hull.



7. When I sanded the transom, red appeared. Apparently it was just below a very thin surface layer of the ply. I used one of the bulk-head frames to create a new transom as I made the stern just a bit wider above the waterline for more storage space. Serves me right for fiddling and using scrap pieces. So my daughter and I came up with a drawing which we applied using BEM's instructions using tissue paper and a printer. Also used white and brown epoxy pigment additive for covering up some of the red spots and as back-ground for the print. My daughter got a big kick out of doing this with me. She's named the fish Bubbles and Duck.

[scottrunnr]

The fore and aft decks have been glassed to the hull and the seam sanded. Below are photos after I took it outside for sanding but before applying epoxy coats. Not the best pictures I'm afraid.

I'll take more photos after I get the final epoxy coats on but before varnishing. I'll take a set of photos without the side decks (the canoe-type configuration) and a set with them (fishing kayak configuration).

Oh, I almost forgot to give you the latest weight figures! Base boat without large hatches, rod holders, and insulation/etc...about 70lbs! With all of it... about 90lbs! That's 50+ lbs or a third+ lighter than the original!

Decks glassed & sanded but, no final epoxy coat

[scottrunnr]

an update on the weight. In my excitement I forgot to account for the weights I used to balance the kayak because of the tight quarters in my basement. The full up weight with my hatches, rod holders, and insulation with secondary walls is 84lbs. That means a base weight of about 64 lbs!

[scottrunnr]

Matt,
Between lousy weather this spring and my kids having sports events every weekend, I haven't been able to give the new yak her maiden voyage. I finally got to take her out this past Saturday with my wife. We took her out on a quiet stretch of the Charles river as the water temp is still pretty cold.

The 50 lbs we took out of her compared with the previous build make her so make easier to handle both in and out of the water! She was a joy in the water! Below are pictures from the maiden voyage. It'll probably be another 3 weeks before I can take her out on the harbor for her first fishing run and really put her through her paces. I can't wait!

[scottrunnr]

The base weight (before hatches, rod holders, battery compartment, etc) was 67lbs! The weight with hatches, rod holders, etc. was 85 lbs. That means we dropped 58lbs off the original loaded tandem! That's a 40% drop in weight!

I then insulated the aft fish compartment and added secondary glassed walls to it which brought the weight up to 90lbs. (I'm saving 10lbs of ice this way). That's still 53 lbs lighter than the old kayak!

[scottrunnr]

Matt,
I'm sorry it's been so long since I updated you on the new tandem. I've gotten out 3 or 4 time in the last month or so. The new tandem is fantastic! The 50+ lbs we took out of her has made her incredibly manueverable, fast, and easy to transport. We had to race in to beat a thunderstorm on one outing. She just flew through the water and tracked dead straight. Amazing! We've faced some good waves and fished hard and found her extremely stable.

Going without the cockpit side-walls has produced several benefits in addition to weight saving and easier build. First, the wider cockpit is more comfortable and makes it easier to land fish. This is especially so for my large 230lb buddy. Second, since the cockpit floor has nothing attached to it other than a hatch, it is absolutley air tight. When I open the hatch after the temp has risen, it's like letting air out of a balloon! The air woshes out. The lighter hull also has us rising above the waves better. The lack of a cockpit combing has not resulted in any more water coming in when we face waves. Whatever water does comes in drains easily with us riding higher from less weight.

In short, I'm absolutely thrilled with her! Below you'll find some photos. Some photos have my 230lb buddy in them that we designed this for in the first place. He loves going out and has become a very good paddler.

Rigged for fishing







Hull shots









Friend with fish

[hairymick]

Geez Scott,

Your boats and your builds just continue to get better! - better even than your remarkably very good first one.

Your build thread is like a complete "how to" on a very complex build and is as superb as the boat itself.

Congratulations mate - enjoy

[scottrunnr]

Thanks Mick! You'll note throughout the build that quite a few aspects of the build are inspired by/copied from you!

This boat has been a blast to fish from. It's great to share the fun in a tandem with my friend or my son or my daughter. Doesn't get much better than that!