Budget kayak build [Archive]

Spelunx

3rd November 2018, 10:14 AM

labr@

3rd November 2018, 01:42 PM

A few random thoughts to get things started:

For a budget build consider doing taped seams but no glass on the rest. Won't last as long but is cheaper and also quicker.

I suspect you will still need close to 5kg of epoxy if you want to make it completely waterproof. For a shorter life expectancy you can just coat it with a marine grade single part urethane. You would need to put this over epoxy anyway to protect it from the sun. Suitable urethane are available at the big green shed.

Even for a budget build I would only use 1 of 3 brands of epoxy, West, Bote Cote or FGI.

Marine ply from the big green shed will be usable but inferior. There are various types of ply with waterproof glue but the Marine grades should also have even ply thickness, more plies for the same thickness and little or no voids.

Start a build log when you get started so we can all give you plenty of conflicting advice:U

Arron

3rd November 2018, 04:14 PM

Bit of background. I made three stitch and glues about 10 years ago. In my normal way, I started out building expensive but ended up building inexpensive. All three boats have revealed no faults and all look now pretty much like new - none of the incrementally cheapening decisions I made about materials made the slightest difference - at least not in the first decade of their lifespan.

Wooden canoes will last a very long time if they are not left to sit in water, not left with water sitting in them, and kept out of the weather and sun. When done, I take my boats out of the water, dry off any obvious water, and store them in the garage. If your kids wont do that, or they are hard on things generally, save yourself the pain and buy a cheap secondhand fibreglass canoe.

But if you want to go ahead, and to limit the spending, this is what I'd use.

Consider using a good quality outdoor ply. Marine plies are better, no question of that, but outdoor plies use the same waterproof glue. The plies are thicker, there will be more surface faults, and there may be internal voids if you don't choose well, but a well chosen external grade ply will do the job for kids. I have a kayak a friend made of external ply when we were kids (marine ply, fibreglass and marine paints were far too dear for us back then) and its still with me and doing well today - 45 years later. Well built and always treated well. Shop around and find external ply with no voids - it is possible.

For marine ply I used variously Okume (expensive) Fijian cedar (medium) and cheap nameless Asian-sourced hardwood. All have done the job well, though I think the Okume was nicest because it was lightest and strongest.

If you go marine ply, the Bunnings stuff is the same as the Asian sourced hardwood mentioned above. It will be fine though it will be a bit heavy and stiff. At least you wont be destroying any desperately endangered West African rainforests.

Use epoxy as a glue only - ie use it for scarfing, taping seams, filleting seams, gluing on gunwhales etc. I think you will need 1-2 kg for that.

Use polyester resin for sheathing the bottom, and maybe inside around the cockpit as kids are pretty clueless when getting in and out.

Any fibreglass cloth will do - its simply not a quality issue.

Use a marine varnish for topsides. Skip the epoxy soak coat. A full epoxy envelope is a wonderful thing to have, but its expensive and more suited to something you want to last forever.

For the few timbers that are required, I used recycled Oregon from our old pergola. A light wood perfect for ribs, gunwhales, bulkheads, keel or whatever else is needed.

In one case I needed those frames that run perpendicular to the keel. These were 19mm thick or thereabouts. I used ordinary external ply for these. There were voids. I filled them. It hasn't mattered.

For paint, I love marine paints but they are expensive. Basically, the difference between marine paints and house paints is one of incremental quality and UV resistance. A house paint will do the job if you store the boat as mentioned above.

I think if you do this you will get a boat with a 10-20 year lifespan if treated well.

Id probably still be going secondhand fibreglass for kids.

If I can find it, I'll attach a photo of one of my stitch and glues, for motivation.

cheers

Arron

ian

4th November 2018, 10:28 AM

Hey everyone, i got a book on stitch and glue boats from the library the other week, and now i have an itch i need to scratch! I want to build a stitch and glue kayak for the kids to use on the estuary during holidays, so it doesnt need to be a masterpiece. Looking into the prices of marine ply, i can save a fair bit of money buying it from Bunnings. Then comes the epoxy, fibreglass, etc.

being for the kids, and my first build, I amd trying to keep the budget as low as possible, whats the bare minimum i can get away with? Will cheap marine ply be ok? What about budget brands of fibreglass and epoxy? Any recommendations or experience to pass on?

I have all the tools, workshop etc, and have built furniture, decks, etc in the past, so i am keen to extend my skills to something fun for the kids.....
perhaps the most important criteria is how easy will the kayak you build be for the kids to control.

lighter is always good when it comes to moving the boat both on and off the water. Unfortunately, light and inexpensive are mutually exclusive.

will the boat be a single, double or triple seater?

deck rigging (something to hang onto after they fall out or capsize) and internal flotation (so the boat has positive boyancy even when full of water) are always good.

don't underestimate the effort involved in lofting and cutting the ply to shape. A friend who at last count had built 3 kayaks, went with pre-cut kits for boats 2 and 3 to avoid the lofting, cutting and fine shaping.

I'd recommend using epoxy (thickened where needed) to glue the seams, and thickened epoxy for fairing (though I believe you can buy fairing compounds.)

glass wise. Definitely glass the outside of the hull and internal areas subject to high wear. I'm not convinced that the internal seams need to be taped as well, but I suggest an epoxy primer coat is a good idea.
For lower cost, a lighter fabric will require less filling coats.

my boat
http://www.woodworkforums.com/attachment.php?attachmentid=445214&d=1541287918

the build table
http://www.woodworkforums.com/attachment.php?attachmentid=445213&d=1541287823

Spelunx

4th November 2018, 06:09 PM

Thanks guys! All that info is amazing, great to see I can build a boat using cheaper materials, and still end up with a halfway decent result.

I really like the Mill Creek 13 design in the Chris Kulczycki book I have read. It looks like something the kids can safely use on holiday, as well as being big enough for myself to have a paddle.

I still have a long way to go before I commit myself to the project, however the answers above have given me more confidence!

They will definitely be kept dry and out of the weather, stored on top of the camper trailer in the shed.

Arron

4th November 2018, 06:26 PM

The mill creek design is from Chesapeake Light Craft. The first two boats I did were CLC designs - the North Bay and the Oxford Shell. The last one was a self-design but based on CLCs Annapolis Wherry. I only bought the book and scaled up the plans - I didn’t buy the full size plans. Millions of people have built his plans - he probably has no idea how many. They are simple and no-nonsense plans.

I think the mistake I made was to build overlong boats - 18 to 23 feet long. This has lead to problems storing as we have moved houses etc. Nice on the water but difficult to find the space.