Currently in the works will be a collapsible, or folding, SOF made with plywood frames and PVC stringers. Two problems I've wrestled with have been joining the sections of PVC tube, and finding a simple method for attaching the frames and the stringers. I think I've got a technique which solves both problems at the same time, is cheap, imple and fast.

After looking at a picture of Rick Allnutt's PVC frame (which I suggested he make with standard PVC connectors) I realized how "lumpy" they made the stringers. Sorry Rick. Mea Culpa. I have a better way. Internal connectors.

The inside diameter of 1 inch schedule 40 PVC is just a small amount larger than the outside diameter of 3/4 inch schedule 40 PVC. I thought of spending a lot of time sanding down the 3/4 inch pipe to make it fit, but came up with a bertter solution. A single slit along the length of the 3/4 inch pipe removes enough material so that it can be squeezed together and fit tightly inside the 1 inch pipe. I slit 6 to 8 inch distances on longer pieces of pipe, and then cut them off.

One end can be glued into the 1 inch PVC with regular pvc cement, and the other end can be freely inserted into the neighboring piece of PVC as the chines are connected. When assembled the pipe has a smooth profile.

But, if I don't run the two pieces of pipe totally together I can drill a hole in the edge of my frames which is the same as the iner diameter of the 1 inch PVC, insert the slit pipe coupling, and use this to join two pieces of the 1 inch PVC at the frame. Trapping the frame between the ends of each section of 1 inch pipe should keep it in place. The length of the inner pipe will ensure that the 1 inch PVC can''t slip off, but I am considering a "button" system to hold it better.

Pictures of these joints will come tomorrow or Saturday, depending on my schedule.

PGJ