I decided to use 1 1/2" PVC pipe since it is only a little more expensive but much sturdier than 1 1/4" pipe. I also made the arbitrary decision to space my supports at 3'.
- Determine the number of supports by dividing your boat length by 3.
- Take a width measurement at each support location.
- Use a Triangle Solver or some basic trig to determine the lengths of pipe required for each side given width and the angles (90 and 45 degrees).
- Cut the pipe to length
- You will also need to cut 3' lengths of pipe to go between each support and a length of pipe for each end.
- Make the top 90 degree connector
- I used a single 90d PVC female-female connector attached to a female-female straight connector with a machine screw.
- Drill a hole in the center of the 90 and straight connectors.
- Attach them together using a screw and nut.
- I also drilled holes close to the edge of each side of the straight connector to fasten the connector to the lateral support pieces.
- Glue the entire support structure and connectors together using PVC pipe glue.
- Assemble the whole thing together with pipe glue using the vertical supports and the 3' PVC pipe sections. Do NOT GLUE!
- Use additional screws to hold the 3' pipe sections into the connectors.
- Cover the connectors with foam to prevent tarp chaffing.
- Use tie-wraps to secure the frame to lifelines or whatever else you have that is sturdy.
The slope of the frame seemed sufficient to keep snow from piling up on top. I didn't have to shovel it at all through the winter.