When I went to see about buying one of Thule's fine Portage canoe carriers, I simply couldn't justify spending $120 on a device that I might use 2-3 times a year at most. So I made my own for a little over $10.
Step 1: Where the Inspiration Came From
I'd love to say that the carriers I made were made from space-age materials, carbon fiber, various polymers, and was capable of carrying 50 times the weight of my canoe. Well, that's not the case. They're made from a scrap of 2x4, 1/4" plywood, a piece of 1x3, about $11 in nuts and bolts from the hardware store, and a sheet of craft foam. I went the I-can-afford-it-route instead of the if-I-mess-up-I'm-out-a lot-of-dough route. The cheap route worked fine as the set up I made helped stabilize my 17' Old Town Camper canoe on a 700 mile round trip drive last week. Woohoo, they worked!
A little about how the Thule system works: it is designed to prevent the canoe from sliding laterally under the stresses of you turning your vehicle to the left or right. It is not the only thing that holds the canoe in place while you're driving; you'll also need to strap it down to your roof rack as well as anchor it to the front and rear of your vehicle. If your vehicle lacks rear anchor points, check out my other instructable about how to cure that here:
The canoe's gunwales sit on the carriers. They are pressed by the carrier's raised sides. The carrier is clamped to the roof rack or rack system on your vehicle effectively "holding" the canoe by it's inverted top edge. You can see the design and how it attaches in the pictures I borrowed from the web of Thule's excellent product.
This project was a little more of a test for me as I am a very new woodworker and I wanted this to not only look like the product I was mimicking, but to function like it (for the most part) as well. I had a couple of trials and realizations during and after the fact that will hopefully steer you right where I steered wrong first. Let's get started!
Step 2: Materials and Tools
What you'll need:
20" section of 2x4 - left over from other things
20" section of 1x3 - left over from other things
2' sq 1/4" plywood - left over from other things
8 - 3" 1/4-20 panhead bolts - $4.00
8 washers - pack of 12, used 8 - $3.00
8 1/4-20 wingnuts - $4.00
1 - 8" sq sheet of self-adhesive craft foam - "borrowed" from my daughter's craft supplies
These are the tools I used, but use what you have available or suits your preference
drill with 1/4" bit
1/2" wood chisel
measuring tape or a ruler
speed square/combination square or the like
Waterproof wood glue (Titebond III is good)
Step 3: Ripping and "dado-ing" the 2x4
First thing you want to do after collecting you materials is to rip the 2x4 in half lengthwise, giving you two equal halves of 1x4. Take one of the halves and cut a channel down the middle of it that 3/4" wide and is slightly less deep than half the thickness of the wood. I don't have a dado blade or a router so I made several passes to remove wood with the table saw. I then used a chisel to remove the excess material easily.
Make sure to always use a push stick to help move the wood through the saw blade and not your fingers! The picture above was just to show how the saw was removing material!
Step 4: Measure Twice -maybe Three Times- Cut Once
Cut the channeled half and the other 2x4 half into 4, 5-inch wide sections. Make sure your measurements are as accurate as possible because you want your carriers to all be the same! You can see that I have them labeled "top" and "bottom"... I have been known to grab the wrong piece for the wrong reason and ruin it because I wasn't paying attention. This helps.
Step 5: Cutting the Blocks to Shape
A band saw or a jig saw makes short work of this step, but a coping saw or a hack saw would work just as well too.
I measured the tab that the gunwale will sit on to be 2 1/2 inches wide which is also the width of the cross member on my Honda Odyssey's roof rack.I measured a half inch in and from that point, angled down to one inch above the opposite edge on the outside. This created a triangular plan view of the top piece of the carrier. I made it this shape to give my fingers clearance when tightening or loosening the wing nuts when mounting the carriers to the car. I carefully used the band saw to cut it to shape following the guidelines drawn on the wood.
Step 6: Making the Riser Piece
This is the piece that will resist the side-to-side movement of the canoe while you're traveling the most, so it needs to be well attached to its base. I had been told that this method of attachment was very strong so this is what I went with. The channel I cut into the base to hold the riser was 3/4" and a tight fit - exactly how it should be. Don't get me wrong, it took a little sanding to get the fit just right - I very rarely hit the bulls eye first time around.
As you can see in the photo, the 1x3 is actually a 3/4 x 21/2. This means that only 2" of riser will be holding the canoe laterally - and that's all that's needed, so we're good to go there.
For making the riser, I really didn't measure, I just fit the 1x3 into the base, made my marks from tracing that piece's edges and then used a speed square to get my straight lines. Just sort of tracing, really. This way each riser was matched perfectly (well, as perfectly as I could do it) to it base for as good a fit as I could get. I then used a band saw to cut it out. Did a test fit to see how the angles lined up, and then finished it. The last photo is of all the pieces that have been made and that need to be assembled. So far, so good!
Step 7: Marking, Drilling, and a Realization
I wanted the bolt holes to be a fair distance away from the riser so that I could easily get my fingers in between it and the wingnuts to tighten or loosen them without getting my fingers pinched by the wood.
The marks are 3/4" over from the edges and 1/2" up from the bottom. I used a nail set to put the mark in so as to have the drill bit stay put and not "walk" when I started to drill.
Drill two 5/16"*** holes on each base at the marks you made. Do your best to keep your drill as vertical as you can, it will make passing the bolt through and the use of the carrier much easier. I went slightly larger on the holes figuring that humidity might cause them to close up a little being outside and potentially wet from rain or the canoe itself.
The realization I mention came while drilling that there was a pretty good chance of this piece of wood splitting if it ever got hit the wrong way or anything like that. So a little reinforcement was necessary.
Step 8: The Aforementioned Reinforcement
This is where the 1/4" plywood comes into the picture.
I traced the shapes of each base and foot onto the plywood making sure to have the grain of the plywood going the opposite direction of the grain main pieces. Then I cut the plywood reinforcers out on the band saw. Next, I used a waterproof wood glue and a lot of clamps to sandwich the plywood onto the feet and bases. I let the glue dry over night, unclamped them, and then drilled the holes in the plywood using the existing holes in the bases and feet as guides. Worked out pretty simply and added a good deal of extra strength and peace of mind.
Step 9: Test Fit!
This is what it looked like at the initial test fit. All the spacing was good, the width of the pad where the canoe would rest was good, however, even with the bolts tightened down, it was a little wobbly. The solution to this was to contour the bottom of the base and the top of the foot to the shape of the roof rack's cross bar.
Step 10: Contouring the Bottoms of the Bases and Feet
A belt sander really comes in handy for this part as the wheel-end of the sander makes a great, rounded inverted contour. I drew a centerline down the middle of the base and the foot and eyeballed its alignment to the sander and just leaned in. I checked for evenness as I went along so that the base and the foot's contours would be close to the same shape and depth. I repeated this step for all eight pieces and it worked really well.
Step 11: Attaching the Risers to the Bases
Previously, the risers were just held in by the friction of a tight fit, but they needed to be permanently adhered to the bases. I spread on the glue, pressed the risers into their channels and then clamped them into place with several clamps. I left them to dry overnight. I suppose you could also secure them from the underside with a couple of flat head screws for a little extra insurance, but they seemed rock-solid to me as they were.
Step 12: Stain, Polyurethane, Identifiers, and Padding
I chose to stain the carriers black to go with the car and be basically neutral, but feel free to stain, paint, plasti-dip them however you'd like. I thought that the penetrating properties of the stain would be a good barrier against water in combination with the polyurethane.
I applied the stain and polyurethane both with sponge brushes, two coats of stain, 3 coats of polyurethane. Hopefully, that will repel water well enough to prevent the wood from weakening over time.
Since the outset, my goal was to make each of these identical to the other so that it wouldn't matter which base was attached to which foot, but that didn't happen. Minor little variances irked me so that I decided to make each base and each foot a set, like they were numbered in pencil early on in the process, but when the stain went on I had to think of something else. I wound up using a nail set to to tap in 1 through 4 dots on the feet and bases so I would always know which went with which. If you think there's a better way (like making them all identical) go for it!
The padding with the craft foam is probably pretty unnecessary, but it made me feel better about where the gunwales were contacting the carriers.I just used a hobby knife to cut 8 rectangles out that were the size of the exposed riser face and the base in front of it. The craft foam is self adhesive and stuck down really well.
Step 13: Final Assembly and Mounting to the Roof Rack
Assembly is easy. Slip your bolts through the washers and then slip the washered bolts through the foot from the bottom up. Slide the foot with the bolts under your vehicle's roof rack cross member. Holding the foot from below so the bolts don't slide out, place the base over the bolts and screw on the wing nuts. Don't tighten them down all the way yet. Mount the other three the same way. Place your canoe, upside down, on the carriers and adjust their placement as needed. Then go back to each and tighten the wing nuts down firmly, but not over-tight. Your canoe should now be held lightly in position but have little to no side to side movement.
These little carriers in combination with 2 load straps, front and rear ropes and mounting points will safely secure an otherwise pretty unwieldy load to the roof of your vehicle without worry even at highway speeds.
As always if you have ideas to improve this (I do, but now have other things the wife wants me to do) or if you make your own set, I'd love to know/see it!
*** The realization I had after the fact (the one I mentioned way back in step 7) was that when I went to remove the carriers after our trip, the wood had swelled from the humidity and wouldn't release the bolts. At this point I had only drilled 1/4" holes for the bolts, NOT the 5/16 holes as in this Instructable. After some rubber malleting the bolts out and fortunately not damaging the car or carriers in anyway, I immediately upped the hole size!