Re: (IAAC) Concrete mounting

At 12:08 PM 5/3/98 PDT, you wrote:
>Perhaps a little off-topic, but I think there would be enough expertise 
>on the list to help me.
>I'm planning to permanently mount my scope on a concrete pillar to 
>eliminate the need to align the mount every time I use it.  However I am 
>not sure about how deep the pillar would need to go to give reasonable 
>stability.  The soil I would build it in is very clayey, and subject to 
>gleying and saturation in the Winter and cracking in the Summer.  Whilst 
>I would like to create the 'ultimately stable' pillar, I am limited by 
>the fact that I probably won't be staying at my current residence for 
>particularly long, and a four foot deep concrete-filled hole in the lawn 
>probably wouldn't be a good selling point for the house.  The scope and 
>mount and any accessories would never weigh any more than about 50 kg.  
>What would the minimum sort of depth be?
>Thanks in advance,
>Get Your Private, Free Email at http://www.hotmail.com
>Hi Paul

I'm currently in the midst of building my own roll-off roof observatory so
I went through what you're going through now. In my case I went down 5' but
4' probably would have been sufficient as I live in Ontario, Canada and our
frost goes down pretty deep some winters. Why don't you go down at least 4'
in a 8"-10" sonotube, put in a piece of rebar for extra rigidity (only up
to ground level) then if you ever sell your home it would'nt be to hard to
knock off the portion that is sticking out of the ground and then cover it
with dirt or put a flower planter over it.

       good luck 

        Mike Wirths