[Ian Robinson]

Originally Posted by tempestwizz

I went to the local re-cycling place and got some slow-combustion heater flue tubing to use as a former. I dug a hole as deep as I could - approx 1 metre square by 900mm deep. Whacked in a number of star pickets at angles into the clay at the bottom. Welded and wire-tied other star-pickets that run up through the former. On the top of each of the 4 (vertical) star pickets, I welded 3/4" threaded rod that protrudes through the top of the former.
Filled the hole and former tube with hand-mixed concrete in one exercise. Works a treat. About $50 for star pickets $5 for the former, and $50 for concrete. Absolutely solid!
Later laid observatory slab around the pier.

Couple of pics pre, and during obs construction (with home-made LX90 wedge)

BC

Looks good.