Saturday, November 22, 2014

Current Status of the Backyard Observatory

My last post brought you up to date in mid-April when the telescope pier was poured.  With the heat of summer, it seemed prudent not to schedule any work in the yard, so I waited for cooler weather.  As shown at left, the pier was pretty much unchanged for 7 months until Fall arrived.  With the astronomy Expo a couple weeks back, the idea got kicked to the front of my thinking and the evening we spent at Starizona I asked Dean Koenig about a contractor he recommended for observatory construction. 

The following Monday I called his recommendation John Vermette, we visited the observatory in his back yard the next day (Veteran's Day), and 6 days later he was in my yard building concrete forms!  Originally I was thinking of a 12 X 12 foot floor, but with it laid out, it just seemed so huge - taking up so much space in the yard that I cut it back to 10X10.  The interior will be cozy, but most of the time I'll likely be by myself there, so should work out ok. 

John is willing to let me jump in and help him, hopefully saving him some time and me some money, and I do some things on my own.  For instance, while he built the forms for the slab at left, I put in the trenching and ran conduit for the electrical line that will get buried underground and under the slab for power, shown at right.  He called me later in the day on 17 November - the concrete was coming Wednesday morning!

So I had a few more tasks to do before then.  I needed to clear, or at least move my "storage pile" against the fence as I would need to remove a section so the cement truck could directly access the yard.  After pouring the pier in April, I couldn't see doing a slab in small batches, so ordering a truck seemed the best route to go.  John ordered 2 cubic yards for the lil' slab I needed...  At left you can see my effort in removing the fence for access, and the layer of foam around the pier base to isolate the slab from the telescope.  John is watering down the ground so the dry dirt doesn't pull the water out of the concrete too fast.  At right, the truck has arrived, and he and the assistant he hired to help an hour or two were working hard on the pour.

I also invited our buddy Frank, who had helped me with the mixing and pouring of the pier in April.  Realizing the truck would likely have extra, in the space of a few minutes, he rigged up some forms from old 2X4s to pour some "stepping stones" to lead up to the entrance of the observatory door.  At left, as the slab form is filled and the guys were working on that, Frank is in the back, ready to pour the sidewalk sections.  After pouring and letting it set up a bit, he worked on finishing these sections.  Once cured, they'll be separated from the forms, and bedded in a base of sand for a permanent path...

Meanwhile John was taking care of business on the slab.  While I've seldom worked with concrete since leaving the farm back in the '70s, it was fascinating to watch someone who knew what they were doing with the right tools.  I suspect the flat-screened tool at left serves a similar purpose to the vibrator I used on the pier.  By jiggling the tool, it works the bubbles to the surface to make a stronger slab.  At right, he puts a groove into the slab so that if it cracks, it will crack in a controlled manner along it.  You can also spot the "J-bolts" installed around the periphery of the slab, which will hold down the walls of the building securely.

Over the next couple hours as the concrete set up he continued working the surface, smoothing out the top and filling in what looked like little cracks, believing that the dry air was causing it to dry too quickly.  I think he was a little paranoid, as a few days later, it looks fine, though still looks far from fully cured and dried.  I followed his directions and hosed it down occasionally. to keep it from curing too fast... 

On pour day, he also brought the supplies that he'll use for building the observatory.  At right, the current status of the observatory is shown.  The slab, siding at left against the now-replaced fence, a pile of 2X6s, the metal door at center leaning against the far fence, and at right is the blue equatorial mount, with a wooden cover over it to keep weather out the last couple years.

Progress will be made quickly as John is coming Monday to frame up the walls and the door will go in by Tuesday.  The roof, following my fold-down design, will take longer, but he'll build it in place and we'll work on my plan together as his schedule permits.  Meanwhile I'm thinking I've got to get the mount installed before the walls go up - tomorrow is installation day!

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