I'm designing a garden seeding tool that is roughly similar to a hollow walking cane/stick. At the top is a smallish funnel and at the bottom is some assorted gear, but we can imagine it as a 2" hollow extension that slips over the end of the cane and comes into contact with the ground.
Stresses will be similar, but somewhat less than one would have with a walking cane.
I'm considering trying to cast the whole thing in resin, but it seems more attractive to cast the top funnel and bottom gear in resin using a 1" aluminum tube for the tube part.
My problem is that given this is a tool that should be expected to last a few decades, I'm not sure how to join the aluminum to the resin. I thinking some sort of glue, or perhaps a collar with bolts.
The only thing I really don't want to do is perforate the aluminum (like putting a bolt through it) since I want to keep a smooth uninterrupted tube on the inside.
I'm still in the design phase, so all options are open. What would you do? The aluminum tube would have a 1" inside diameter. If I resin cast the entire tube, it could be slightly trumpet or funnel shaped all the way down to make for easier demolding.
A related problem is how to color coordinate the aluminum and resin.