On Mon, 12 Dec 2005 19:34:45 -0800, "SteveB"
wrote:

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.

To be legal you must use a davit approved by the American Flange
Institute, known as an afidavit.

Sorry, couldn't resist it.

In more of a helpful vein, don't trust welded rebar. Rebar can have
fairly high carbon content and become brittle with welding. Use mild
steel or HRS bar. Some HRS also has some carbon content, but usually
less than rebar; it'll be OK if not quenched after welding.