If you’ve ever tried to glue pipe to another material, such as polystyrene to plastic, you will know that it can be difficult to get a good strong joint. Pipe for all it’s large diameter tends to have a very small surface area on its edge.
To help with this use a peg for the pipe to fit over, this increases the surface area for the glue to adhere to and produces a much stronger joint. Pegs can be made from pieces of dowel or even BBQ skewer for smaller pipes, right up to wine corks or foam blocks for larger pipes.
Simply glue the peg where you want the pipe to go and then glue the pipe into position over the peg. The added surface area will hold the pipe securely in place.