RickK

Dear RickK, I am currently no longer talking to yourself or anyone else in this thread, due to you opening my thinking to a wider range of problem solving on a budget! In revenge, I was wondering if you had seen this.....

http://m.ebay.co.uk/itm/251630134644?cmd=VISPEC

No, I've never looked at a steel tank but if I had a way to cut and weld it I probably would. I always found it funny, anytime I was out driving and see a grain silo or a TV satellite dish I though "That would make a great dome".  

I will need to check, I have looked at the pickup truck tanks and it was 1/4" (6.35mm) thick but if the larger tanks are that thin it would be a problem. Another choice I had was a custom metal building that is about the same price.

That is a possibility, I haven't looked at one up close. Where I retired from they used 55 gal drums with the tops cut off for trash cans and they were pretty rigid.  I like spaceboys idea as well.

I had thought about different ways, there are lots of options and even tanks with open tops more like a tub. You could do any configuration you wanted, for a few hundred you could get a tub type and a smaller dome tank and use both, or even the large dome tank and a smaller (less volume) tank with the same dimensions for parts make the shutter. Make the top rotate, then half the dome (shutter half) rotate on top.

Some folk used to use the hemispherically shaped tops of grain silo's as observatories.  However that was when I was younger (and plastic hadn't been invented yet  ).  Looks like a good idea as long as the cost is reasonable.

I had thought about that and it would make a good dome, in my area they are hard to come by. Another Idea was to use a old large type satellite dish for a dome.

Just a picture I found to give a idea of size, and I was thinking more about white as a color. It would be water proof and you could use the screw in caps as a point to add wiring. 

I was thinking you could use a ribbed type tank, maybe a 1400 gal. It would be around 700 USD, for the 80"x 90"H. Cut the tank just below the top rib (Red in the picture), then it would be like a cap. Then it could be a lift off or flip off, but I think any type would be fairly easy. Plus its water tight, and UV proof.

I was looking at how to get a small home dome set up fairly cheap, I was thinking about using a water storage tank as the dome and lower half / floor. Using a 80" dia x 90"H poly dome tank, cut a few inches below the rib to make the dome cap and use the lower half for the walls and floor then the top could be lifted off for use. The top @ 55 lbs. would be farly easy to lift off for use. There are other tanks I've looked at also and may look at a shorter tank.