Fiberglass inside and out?

[haydensimons]

So I'm building the free laker as my "starter". I've got a pretty good background in hobbiest woodworking so I've definitely got all the tools to build a strip kayak. I needed somethign quick though since summer is upon us. I figured if this one works out, the winter will be time to build a really nice one.

So I'm using 1/8 luan from HD, since its the closet thing I could find to the thin plywood that is needed locally. Called all over and no marine grade under 1/2 inch in sight.

I looked for sheets without voids. I've got all the parts cut out, stitched, taped and epoxy'd the bottom, stitched on the sides and am now in the process of stitching/taping the deck. So my plan was to use fiberglass tape on the inside joints and a sheet of cloth over the outside of the bottom and sides. No fiberglass on top (except for the tape on the inside joints.

Now I'm concerned that I need fiberglass cloth on the inside bottom as well. Then I started thinking, heck, I need it on the top too. Then I figured, if I continue this way, I'd have been much better off buying a plastic kayak for the summer.

So, thoughts? I wasn't planning on installing any ribs/dry bulkheads...just going to leave the inside open. Do I need another layer of fiberglass on the inside bottom? Top?

[Teddy Madison]

I'm in the same boat (couldn't resist), I too am building the free laker. I have 5.2mm from Lowes and I would suggest you glass the whole thing, inside and out. This stuff is pretty bendy.

Edit: I forgot to add that it will check if it's not glassed. I was playing with the coaming and just that little bend made it crackle.

[jem]

You do need fiberglass coverage on the inside and outside of each seam. The exception being bond the deck to the hull. We use a wooden batten (strip) on the inside for that.

[haydensimons]

Thanks, Wayne. Anyone that's completed this kayak with the thin material got any input? The plans don't actually call for fiberglassing both inside and out. I'm at the point now of maybe giving up on this. If I have to use cloth on both inside and out, I'll probably end up needing more epoxy as well. I've already dropped 200 in epoxy in fiberglass.

If I need to fiberglass all sides, I'll probably need to fork over another 200. All for something that I'm planning to upgrade anyway. Thinking if I need to do this, I should have probably saved the 300 I've already spent on materials plus the 200 I'd need to spend and purchased a kayak in a store.

Please tell me I don't need to fiberglass all sides.

[haydensimons]

So it sounds like you're saying that just tape on all the seams (except the hull to deck) and fiberglass cloth along the whole bottom and sides should be enough?

I'm feeling much, much better.

[jem]

Thanks, Wayne. Anyone that's completed this kayak with the thin material got any input? The plans don't actually call for fiberglassing both inside and out.

Yes they do.

I'm at the point now of maybe giving up on this. If I have to use cloth on both inside and out, I'll probably end up needing more epoxy as well. I've already dropped 200 in epoxy in fiberglass.

If I need to fiberglass all sides, I'll probably need to fork over another 200. All for something that I'm planning to upgrade anyway. Thinking if I need to do this, I should have probably saved the 300 I've already spent on materials plus the 200 I'd need to spend and purchased a kayak in a store.

Please tell me I don't need to fiberglass all sides.

How much epoxy and fiberglass did you buy? If you follow the build instructions, you'll only need what's specified in the Bill of Materials that came with the plans.

[jem]

So it sounds like you're saying that just tape on all the seams (except the hull to deck) and fiberglass cloth along the whole bottom and sides should be enough?

I'm feeling much, much better.

You could apply fiberglass tape only to the seams, inside and out.

Or you could apply cloth to all wood surfaces.

Or you could mix and match. But the seams need fiberglass (except when using a seam batten like for the deck).

[haydensimons]

My thought was that I'd do the lightweight option 1. if my math is right, 1/8 inch is a shade thicker than the 4mm that the lightweight option 1 calls for.

I bought 1.5 gallons of epoxy, 2 quarts of thickener (fumed silica I think), 50 yards of 4 inch tape.

When I was placing the order, I got a little nervous, so I started thinking that taping all seams as the instructions called for as well as layering the fiberglass cloth over the bottom would give me a little more strength and a little more durability. So, I added 6 yards of 38 inch cloth.

So I'm planning to tape seams inside and out and also put the cloth on the bottom and sides.

[jem]

Be careful not to over use your epoxy. Only use enough to wet out the fiberglass. Try not to waste by mixing large batches and not using all the epoxy.

Always do a dry run and sort of orchestrate your steps. You should have enough epoxy. Might get close to running out if you're applying tape to all seams then fiberglass to all surfaces. So be very careful.

3mm is just a hair under 1/8".

4mm is close to 5/32 or 3/16.

[hairymick]

G'day Hayden,

I built the prototype of this great boat. I used 3.2mm or 1/8th luaun ply that was utter rubbish.

I would perseveer with your build if I were you. I don't care what plastic kayak you are thinking about buying, it will never be as good to paddle as a laker - period.

I would completely encapsulate you Laker in light weight fibreglass cloth - inside and out. This will protect your cheap interior grade ply and add much needed strength. You have gone this far, the cost of the extra resin and cloth is minimal compared to what you will pay for a plastic boat (unless you are considering one of those super cheap Chinese made plastic pigs that are flooding the market now.)

I have shot grade two rapids, bounced of many rocks (not advised) played in surf and target serious sport fish in my laker. She is vary capable in all of them.

Would I consider building another one should mine ever fail. HELL YES!!
Mate, this is my go to boat. She is the one, i can grab easily, throw on the roof of my car and take off for a couple of hours on the water. No fuss, lightweight, great to paddle and a delight to own.

keep going with your build mate. You won't regret it.