So I have been pretty unimpressed with the Yakima stackers, $100+ for round stock, rivets and plastic. Also it is also only rated for 4 boats, and I have the capacity to do over 8 on my racks.
This sent me to Lowes to try and devise a cheaper, stronger, light weight alternative to fit on my round bars.
I came home a while later with:
10' of 3/4" copper pipe,
3/4 x 1 1/4 x 1 1/4 copper T-connector (2x)
3/4 x 1 1/2 x 1 1/2 copper T-connector (2x)
Hose clamp (4x)
Spray paint- primer and Satin Black
Here are the connectors:
First I cut the two smaller T-connectors in half down the spine. I used a dremmel, but a hack-saw would work
I then heated each up with a torch and using a flat-head screwdriver pried open the back of each until there is a gap 3/8" wide. This I did by counter prying two flat heads, then once there was a big enough gap, using one levering against the hole in the bottom.
Using a pipe cutter I cut two 21 inch sections of pipe. Then assembled as shown:
Apply JB weld to the inside of each connecter as shown then let sit overnight.
That's as far as I have gotten for now, I'll add to this later.