Friday 14 April 2017

New akas

I thought I was buying thicker-walled tubing for the akas (cross-bars) for the new amas, but it turned out I bought the same size. It's 1" diameter, the wall is one-sixteenth of an inch thick. I got two 8' lengths. I replaced the old akas with the new tubing anyway, because the old tubes had quite a few extraneous holes in them, as they had been salvaged from a previous installation.
I started out putting the amas at the ends of the 8'-long akas, but it didn't look right: there was too long a piece of tubing for the size of it, in my mind. So I tried the old akas; too short, the amas too close to the waka (main hull). Decided to add two inches each side, making the akas 7' long. To my mind, it looks to be in a better proportion.
Since I didn't get the thicker-walled tubing I thought I was getting, I'm seriously thinking of filling the (marine/aircraft grade 6061 aluminum) tubes with wood, in order to add strength. Dowels are too heavy, so I'll have to cut them from a plank of some light wood, like pine, and plane corners off. It's better if they don't fit exactly—for instance, if there are flat spots the length of the dowel—as that leaves more room for the epoxy glue to hold the core and skin together.


Bumpers in use

The boat got moved into the shop today. This photo shows how the cart is attached to the boat, and the bumpers in use for the first time.
They're so slippery, and it was so windy, I had to tie the boat to the mirror so it wouldn't slide off the car!



Thursday 6 April 2017

Car rail slider-bumper things

I noticed that I'd made a small crease in the roof of the car (yellow arrow below) from manipulating the boat on and off. Also, some red paint from the bottom of the boat. This is because I lift one end of the boat on or off at a time, resting the boat against the car before picking up the other end. So I decided to make and install a bumper/slider thing to attach to the roof, that the boat can rest on and slide on when coming on and off:
The bumpers are on both sides of the car, since I never know which side I may be able to offload on. The material is the same stuff that plastic cutting boards are made of (UHMWPE). It's tough and it's slippery.
The bumpers are attached to the roof of the car using rivet nuts and countersunk flat-head stainless machine screws threaded into the nuts (the heads don't protrude to catch on). I borrowed the riveter mechanism from the garage across the street, drilled holes in the plastic and the roof, attached the rivet nuts in the holes, and then screwed the screws into the nuts through the plastic. I put a doughnut of Sikaflex caulking around each nut beforehand, so that water can't penetrate into the car.
The rivet nuts are used so that one doesn't have to tear the inside of the car apart to put a nut on the inside. The nuts are now hidden (and permanent). One advantage to rivet nuts over rivets is that one can take the item off if needed, by unscrewing the bolts.

Oh, by the way, how do you like my little cockpit cover? It's made from a reinforced plastic tarp left over from Firefly. It has UV resistance and of course is waterproof. It's not made of woven strands like so many tarps are, so the waterproofness lasts.
The tie-down points are doubled or tripled layers of the tarp material, sewn on with my old Pfaff. The loops are made from black nylon webbing such as you'd see on a backpack strap. And that pom-pom! Hahaha! I guess I can take it off (it came with the car), now that the boat is a permanent fixture. I can always find my car! 😎