I think I have the sequence of operations figured out. Today I epoxied the top caps in place and coated them with epoxy. For this I used System 5 epoxy, since a 5 minute setting time was fine. It just meant wasting quite a bit, with a separate batch for each cap. I didn’t have disposable brushes so I used the folded corner of a bit of paper towel. Half way though I though to heat the part after spreading the epoxy, thus lowering the viscosity and making for a smoother surface. You can see the epoxy coating on the caps by the gloss.
I also cut interconnect wires and removed the silicone coating from the ribbon section ends. Soldering wires onto the contact points is a finicky, frustrating operation which I will tackle tomorrow. If that goes well I will wrap the ribbons around the copper pipes. Then I’ll assemble the pipes into the tubes and epoxy the tops to make the copper/wood transition waterproof. I’ll tack the spiders in place but not glue them, so as to allow for thermal movement.