PVC Furniture Fittings for frames
PVC is an excellent choice for building different shaped frames. Furniture grade connectors are formulated to withstand the elements.
NOTE though, that PVC and polyethylene will react. You should paint your frame, or wrap with polyester or felt.
These fittings are all to fit 19mm PVC reticulation pipe, obtainable from hardware and irrigation outlets.
19mm is the internal measurement. It is roughly 25mm outside diameter.