January 2000

Lizard Hollow Observatory Construction Journal
January, 2000:

January 2, 2000 - By the Next Millennium...: A new year begins - but not, I hasten to add, the Third Millenium - and I have high hopes that construction will begin on the observing shed... perhaps even by the dawn of the Third Millenium!

January 5, 2000 - New Plans: Met with a reliable construction guy name of Ben who has agreed to help me put up the Observatory for an affordable sum.

January 24, 2000 - At Last: I haven't written much lately because the the redesign hasn't involved anything particularly new and the construction guy could not start construction before today. But today, we started construction on the Observatory shed! The bottom sill plates were laid out on the slab, which I had waterproofed over the weekend, and the West and North walls were framed. Tomorrow, the more complicated East and South walls will be framed: the East wall has a door through it, and the South wall has a pop-up section to cover the cut-out in the South roof end that is necessary to clear the telescope.

The West and North walls framed-up. The bottom sill plates are screwed to the concrete slab with 3"-long Tapcon anchor screws. All of the vertical studs are toe-nailed into both sill plates using 3"-long wood screws.

Ben is to the left and I am to the right in this picture taken at about local noon and facing Southwest. That we are both working in shorts and hats indicates the intensity of the January sun on the Sonora Desert.

A safety note: Both the top and bottom sill plates are of pressure treated lumber, to repel insects and inhibit dry rot. A highly toxic cyanide-containing chemical is injected into the wood under high pressure. All pressure treated lumber was therefore sealed with a waterproof, neutral-colored stain before handling, and I'm handling it only with gloves. Putting your hands in eyes or mouth after handling this stuff, or getting a splinter, presents a potentially serious toxicological danger. As I have multiple sclerosis, my concern about this issue is perhaps greater than it needs to be: my construction guy, Ben, says he has worked with the stuff for years and seems unconcerned with working without gloves.

The new design remains essentially the same except that it is of nearly all-wood construction. The only metalwork remaining from the original design are the metal rails upon which the roof will travel, the supporting posts at the ends of the rails, and the outer skin of the building. The building walls will be of corrugated sheet metal, and the roof will be sheathed in 26-gauge flat sheet metal over exterior grade, sealed, plywood.

A detail of the new design that might be of interest is the construction of the rails: Because the rails must be bolted to the wooden frame, rather than welded to the metal frame as in the original design, simple 90-degree angle-metal rails can't be used: the bolt heads would interfere with the run of the wheels. Instead, two right-angle rails were welded together, forming a T-shaped rail. The bolts will go through one side of the "T" , with the wheels riding unobstructed down the other side. A bolt through the end post and a cross-member attached to the post and at right angles to it will anchor the end of the rail and provide a "stop" for the wheels at the end of their run.

January 25, 2000 - Three Walls Go Up:    Today, the South wall was framed.    We left the pop-up section unfinished.     The three completed walls were then erected on the slab, plumbed and leveled, and nailed to each other.    The upper sill plate, to which the rails will be attached, was also nailed to the three erected walls.     Finally,   the lower sill plate was anchored to the slab with concrete (Tapcon) screws on 12"-14" centers, primarily needed to hold the structure down to the slab in a high wind.

The pop-up section obscures more of the Southern horizon than I like,  so we reverted to an earlier design in which the pop-up is hinged so it will swing out of the way.

January 27, 2000 - The Last Wall Goes Up:    The final, East, wall was framed, erected on the slab, and the upper sill plate nailed in.    The wall was then plumbed and leveled, and nailed to the other three walls.     Throughout the day, frequent checks were made of all the walls with a four-foot level to assure the walls remained plumb and square.     The lower sill plate of the East wall, which is split by the door, was anchored to the slab.    Diagonal metal bracing was added at all four walls.

All four walls are framed-up, in this early morning picture. The diagonal metal bracing can be seen. The addition of the metal braces added a remarkable amount of stiffness and strength to the structure. More bracing is needed in the East wall because of the door.

Additional work was necessary on the South wall because of the decision to hinge the pop-up section.    The three-section upper sill plate was replaced with a continuous one, and the studs at the pop-up were ripped out and replaced with shorter ones to support the new sill plate.

January 28, 2000 - "Heavy, dude!":    A final check of the walls to ensure they remained square and plumb was made; minor adjustments were made to bring everything to within a 0.25" tolerance overall.     That such a close tolerance could be achieved is a happy commentary on the skill and care with which Ben has done his job throughout the project.

The two "T" rails, weighing in at nearly two hundred pounds each, were hoisted on to the upper sill plates, positioned, and clamped in place.     This required three of us to accomplish;   in retrospect, a fourth person would have provided a better safety margin.

Holes for the two posts that will support the ends of the rails were dug; we were stopped by the ever-present caliche layer at between 2.5' and 3.0'.     The post that supports the end of the East rail was set into position in its hole, and concrete and local rock were added; the post was braced to hold it in position until the concrete hardens.    By dusk,  we were very cold,   as the temperature dropped nearly ten degrees in the forty-five minutes after sunset, a reminder that this is indeed a desert!

January 29, 2000 - Interlude, with Shoveling:    Ben takes the weekend off. I shovel dirt back into the hole where the East rail support post now proudly stands on its own.    The weather turns overcast and cold in mid-afternoon, with heavier clouds forming by sunset.    It looks as though it may snow in the Catalina Mountains.     It has been a very dry winter so far.    Usually, we have seen two or three snowfalls in the nearby Tucson Mountains and have had several good rains by now.    Nevertheless,   the single hollyhock which I have been nursing along from seed, still thrives outdoors...

This early morning shot shows the East rail and its support post - still well-braced. The West rail is being held to the sill plate by clamps and is not easy to see in this picture.

January 31, 2000 - Rails and Nails and Walls: The East rail support post set-up nicely over the weekend. We had a late start this morning, which was overcast and chilly; no sign of snow or rain in the vicinity, as feared. So, we ignored the weather, and set the post that supports the end of the West rail into position, poured concrete and added local rock around it for additional support. We gathered together the parts for the roof in our garage, which is the only flat area large enough for assembling the roof walls.

By 5:30 PM, we had assembled the East wall of the roof, the somewhat higher of the two sides to which the wheels attach. A couple of interesting problems: two pieces of plywood had to be joined to make the underlayment, over which the sheet metal will be attached, a full 12' 2" in length. It was difficult to get the two sections of plywood square with each other and flat, but Ben ended-up with a solid, square, and flat assembly. Spacer studs were also added to which the three louvers will be screwed.

1999:	2000:
September Journal	February 1-14 Journal
October Journal	February 15-29 Journal
November Journal	March Journal
December Journal	April Journal