Step 1: Balance
-One sheet rigid foam insulation 2" thick. ($25) but really it was free from Swap, who gave me a bunch of sheets he didn't need. I added some extra scrap to make it unnecessarily a bit longer. Boys are funny that way...
-Two tubes of construction adhesive $6 (the large ones. You'll be cutting them open so don't worry about a caulking gun)
-A fine notch plastic trowel $1.50
-A wood rasp. Garage sale price. Who on Earth know$?
-An optional 1/4" sheet of plywood (left over from a $8 sheet) for decking.
-Lots of heavy things for glue pressure. Sandbags work fine.
Total cost for DDC was low. You can buy everything you need for less than $50. But you will agree that price is only a small part of the cost for makers. The real cost- the only truly limited commodity- is time.
Step 2: Expense
1. Lay out the paddle board shape. I didn't have exact measurements to use so I just tried to more or less match the pictures. I took a little time tracing and retracing the profile I wanted onto the plywood and used the cut offs from that to transfer the profile onto the foam Since the SUP will be 4" thick I wanted to make it only 24" wide. Keep in mind that this is kid-sized- 4x24x108"- and if you want to make a 12 footer you'll need to buy more foam.
I liked the idea of a wooden deck but now I see that leaving the whole thing foam by itself would be much easier to make and provides a more grippy footing. Not as pretty though. The best tool for cutting the foam was a fully extended snap razor.
2. Use the caulk to glue the foam together. The best way to do this is to cut the ends off the caulk tubes and then slice open one side. The caulk should roll right out of the tube onto your bottom piece of foam. Use the trowel to spread the caulk evenly, leaving a nice wavy trowel pattern (all the pleasures of a zen pebble rake while still achieving something useful) and then press the upper half down onto it. Place heavy stuff on top and right up to the edges to make sure the halves really stick. Leave them overnight. I wish I had had more sand tubes. Those would've been perfect weights. As it was I used tool boxes, buckets of lead, scrap pewter, casting sand and coolers of water for clamping pressure. I am lousy with hobbies.
Step 3: Rocker and Sculpting
3. We can't leave the board flat. There should be a rocker of a few degrees on both ends. I added a piece of foam to the top of the nose so that I could increase the angle of the nose rocker. I would not do this again. I may as well have just left the top flat; adding that foam increased the SUP's buoyancy by precisely zero since it is never near being submerged.
Cricket here helped me trace out the curve of the nose rocker onto the profile. Once decided on the shape we moved on to the sculpting with a long razor. I love to slice foam- so smooth and easy and consistent.
Once the shape is roughed out I used a wood rasp to remove the rest and to make the curves more hydrodynamic. All this foam is a mess, by the way. I recommend setting up some dust collection plan. I found that kids really enjoy sucking up foam dust with a shop vac almost as much as I disliked emptying the shop vac. Dust all down my front. Luckily I was wearing my tincloth apron but unluckily the polyurethane foam dust married the tincloth coating and won't come off. Now that apron has a dusty pink layer.
Finish the smoothing with an orbital sander, stepping down the grits.
Step 4: Meanwhile, the Deck
Step 5: Absurdly Easy
There is so much beautiful water here in Duluth that we just can't stay out of it. And we have been blessed with a perfect summer so having a new toy on the cheap adds a lot to the fun. The SUP glides beautifully, effortlessly. It makes an unexpectedly good kid kayak too and best of all it can be carried on a 5 year old's head down to the water.