All:
I have been attempting to glue horizontal girders to H columns (uprights) and not having much success. In the prototype, you often see girders that have been "coped", i.e. notched to fit into the web of the column. I have done this for the roofs of ovens in the open hearth. The process is not easy and does not yield uniform results.
The temptation is to just butt-end the pieces together. Yes, it's easier, but the joint is brittle. I did this with my pipe bridge structure and I have had to re-do a lot of failed joints.
Last night I had a thought about how to improve those joints. I'm pretty sure someone else has come with this previously; I don't claim to be the first. Here's the tip: Insert a piece into web that makes it flush with the edges. That creates more surface area for the glue. In this case, we are inserting Evergreen No. 176 (.100 x .125") rectangular strips into the web of Plastruct H-8 columns. They fit perfectly.
After gluing them into place, I can glue the girder to column and the joint has more area to grip. So far, it seems to make a much stronger joint.
Hope that helps anyone in the same situation.
George
