davit advice needed
 

I am making a davit for a hoist. The davit (imagine a figure 4 with a long
leg) will be about 14' high, with about a 3' crosspiece. A diagonal will go
from the top down to the crosspiece. An electric hoist will be put on it.

At the bottom, I want to pour a SonoTube concrete base. The top will be
attached to a roofing timber.

My question is about the base. I had imagined just welding a large washer
to the base of the 2" x 2" x .250" tubing. Then, in the SonoTube, I would
place a round rod post with a washer welded on there. Attach it by welding
to a rebar frame to distribute the load. The washers would rub face to
face, with some lithium grease on them. I figured I would stack at least a
couple of spacer washers on there to keep the welded ones from wearing.

This will be out in the weather 24/7. Snow, rain, sunshine.

I was wondering if I should use some kind of bearing, and if so, what kind?
Mounting a round bearing to a square tube would require some kind of adapter
unless I could weld it on direct.

This is going to get minimal use, only turning 90 degrees, and being used
maybe half a dozen times a month. No heavy wear.

What would you do? The simple washer thingus, or a bearing? Somewhere I
could get a baseplate/bearing combo?

OR?

Advice appreciated.