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Off Topic: Foamie Fishing Kayak w/ a question about epoxy
By:Josh Bryie
Date: 4/11/2016, 9:48 pm

Hey all! Long time reader, new actual member. My apologies if I'm posting this in the wrong section; please correct me if I've got it wrong. I wanted to share my latest, and 2nd build. It is a foamie fishing kayak based off of Rowerwet's Sawfish kayak (found primarily on Instructables.com) built from pink EPS insulation foam from the orange big box store. She is 12' long, 39" at her widest, with a tapering front half. The first couple of pics is her, the BattleYak, on the first (and only so far) fishing trip. The name is inspired from the battle ship look that stems from the front cargo lid.

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I spent, literally, months creeping around this forum, as well as several other apparently popular forums. Talk about slipping down the rabbit hole! The amount of knowledge and depth of experience is dizzying! While I could never recall all those whose ideas were taken into consideration for this build, I would like to thank all those that have and do share their thoughts and insight. Your welcoming attitudes and willingness to share have inspired me to share this build.

Back to the yak; like I said, it is made from the pink insulation foam, glued together with PLP, folded Great Stuff expanding foam, and (in certain low strength areas) 3M spray adhesive. Building on a budget, I followed Josh's (Rowerwet) build and made my first attempt at poor man's fiberglass (PMF) using Titebond II and various fabrics. I realize that this boat won't take the beating the manufactured yaks will. However, it should be easy, quick, and cheap to fix. Once I earn some more honey-do-list capital and make the boss happy, I may opt to build another and actually glass it.

Motor and battery excluded as I already had them, I'm into this boat for about $375 plus a crap ton of time. The time actually wasn't that bad; a good portion of it was spent staring at the bones with a beer in hand trying to figure out how not to screw up the next step. :P I'm told that's actually a requisite as told in the unspoken boat builders' handbook. Honestly, my best guess is maybe 40-50 hours spread over about 6 weeks. She's actually about 99% complete with a few tweaks and finishing touches left.

The performance is great considering I tried my luck at hand-shaping foam for the first time ever. She actually came out to a satisfactory level of symmetrical. After the first trial run, I only hand one tweak to make, and she tracks straight, glides forever (for a relatively light boat of 12'), and is stable enough for me to stand up and fish from. The stability was a major driving force for me to sell my Flats Rat and build this one. I loved my 8' Rat, but at 6'5", 245lbs, she lacked the stability for me to stand and fish, stretching my legs. The BattleYak is stable enough for me to cast from while standing up.

Another consideration is budget (isn't it always for us DIY'ers!?). The recent explosion in roto-molded fishing kayaks has the average one selling for $700 or more for just the basic model yak. I've even seen some for $2500+. Granted, those are Swiss Army yaks that can include anything you could possibly want, there's no way I'm dropping that much money on a yak.

My budget was $400 with everything included; that's materials for the hull, hardware (hitch clips, eye bolts, wiring), glue, paint, pedals, and seat. I've got to say, the budgeted amount went pretty quick. As much as I wanted to, the budget eliminated the possibility of using fiberglass and epoxy resin. I only ever did a rough estimate on how much resin I would need. I stopped after estimating it was going to cost me an additional $150-$175 to go with fg and epoxy.

To counter the absence of actual fiberglass, I tried to compensate the weaker covering by using thicker fabrics in high-wear areas. I have three 6" wide runners on the underside of the hull. The center strake is angled on the corners, tapering to the bow (which turned out better than I could've ever hope for). The other two runners are a conceptual mix of pontoons and what I call hips. They're attached at the extreme side edges of the otherwise flat underside. My thinking on this (as ignorant and inexperienced as it is) was that the hips would provide me that stand-up stability I sought. Whether it is the hips, the overall length, the width, or a combination of the three, it worked. The center is covered with burlap, glued with a generous amount of TB II. Due to the budget drying up, I opted to go with denim from old, unsalvageable blue jeans for the other two runners. Don't laugh too hard; the denim laid perfectly without having to make a single cut, accommodating the unusual contours. :D This pic shows what I'm talking about...

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This is the point where my question comes into play. I am using Behr Premium Low-lustre Patio and Porch paint. However, due to the abrasive nature of concrete at the boat ramp and the physics involved with friction, the paint did not entirely survive the launch and landing. Sections of paint on the bow and stern of the center strake already have exposed burlap. The burlap itself in these areas is surprisingly hard (like broken arm in a cast hard) due to a good deal of saturation with the TB II. My concern is that the "water RESISTENT" glue won't hold up to hours-long fishing trips. With everything that I've laid out, I'll finally pose my question.

With as little money as possible invested, what types of materials, epoxy, or coatings can I use (in conjunction with the paint or not) to make the runners more resilient? Polyester resin is out due to my shop being in the attached garage--can't have overly-pungent fumes entering the house. My concern with standard epoxy resin is that 1) it's expensive and 2) I don't know how the epoxy will react with the foam substrate (flexing, expanding/contracting foam with hard epoxy). My ignorance and inexperience have me at a loss on this one. I know there are all kinds of after market carbon fiber add-ons and other products to save the keel of kayaks, but all the examples I've seen are expensive. Seeing a trend yet? :P Work for Uncle Sam, wife in school, two kids, two cars.....broke. All the time....lol.

I gladly welcome any and all suggestions, comments, recommendations, critiques, and general words. I've got more than 180 pics from this build, so if some elaboration is desired, that can easily be accomplished. Again, thanks in advance and my apologies for the book on my first actual post.

Messages In This Thread

Off Topic: Foamie Fishing Kayak w/ a question about epoxy
Josh Bryie -- 4/11/2016, 9:48 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/12/2016, 5:20 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Bill Hamm -- 4/14/2016, 1:46 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Curtis Fisher -- 4/14/2016, 8:28 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Rob Macks/Laughing Loon CC&K -- 4/14/2016, 11:11 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/14/2016, 4:37 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
scottbaxter -- 4/14/2016, 7:14 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/14/2016, 10:00 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
John D. VanBuren -- 4/15/2016, 7:26 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/15/2016, 2:46 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
John D. VanBuren -- 4/15/2016, 4:13 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/15/2016, 9:36 pm
Re: Off Topic: Foamie Fishing Kayak w/ a question
John D. VanBuren -- 4/16/2016, 9:39 am
Re: Off Topic: Foamie Fishing Kayak w/ a question
Josh Bryie -- 4/16/2016, 2:38 pm