Albireo Observatory

Trenching to install a conduit for power and the network cable, and also digging a hole for the pier, was done in conjunction with running a water line from our well in our field to our new garage and garden area. The ground here is a thin layer of soil over increasingly thicker layers of underlying shale rock. The layers started out so thin a shovel could break them up, but quickly became thick to the point that the small backhoe doing the job could not dig much deeper.

After cleaning out loose soil and rock from the hole for the pier, it is about two and a half feet deep. The bottom is a thick bed of shale. A reinforced concrete pad will be poured on top of it before building a block pier base.

The block base is three rows high in the photo, and sitting on the concrete pad. Shale and dirt are being packed back in around it. Two more rows will be added as the observatory foundation progresses, and in the end it will be about 4 feet tall, although a good portion of that will be underground. It will be filled to the top with concrete once finished.

Digging by hand in preparation for pouring a footer for the foundation. It will be about two feet deep, just enough to ensure the footer is below the frost line. Another row of block has also been added to raise the pier base high enough not to get dirt in it. All this digging was done by hand because there was no budget for a backhoe just for this one job.

After multiple days digging and shoveling, cut up pieces of cattle panels were laid down as rebar before pouring the footer. It took twenty-six 80-lb bags of ready mix concrete, weighing over 2080-lbs. No wonder my back aches.

The first row of blocks is done and just starting on the second row. Two rows will bring the foundation up to about ground level. The outer diameter is 12′ 2″ and uses exactly 26 blocks for a full circle. I’ve never actually laid blocks before, but I’ve watched others do it since I was a kid, so I do know what needs done, more or less. I don’t have the budget to pay a brick layer to do the work, and it would extremely difficult to find one on short notice anyway.

There are four rows total, and for the top two rows that are visible, I switched to split-face blocks that match the house foundation. Actually they are leftovers from the house foundation, except I came up five short, and had to make a three hour trip to the block company for more. Because of the doorway, there’s only twenty-four blocks per row for the top two rows.

I worked all day on a Saturday to finish mortaring all the joints. This was late Fall 2023 and the weather was alternating between cold, rainy days and the occasional nice day, so I worked every good day that came along. I’ve also cleaned up all the excess dirt from digging the foundation, both outside and inside. Then I laid down a vapor barrier inside and poured crusher run on top, thinking this would be good enough, and save the cost of pouring a concrete floor (Note from the future: not pouring concrete inside while it was easy come back to haunt me later).

It’s late, late Fall of 2023 and I was hoping to get the floor done before it got too cold to work. The sill plate and outer band are made from individual block-length pieces joined together with metal plates and J-bolted to the foundation. The joists are 2′ X 8″ lumber and the sub-floor is AdvanTech sheeting. This as far as I progressed before the snow came, so everything ended up tarped over until Spring.

It’s Spring 2024 and the floor is finally done. The wall plate is in the process of being put down, and one final row of block has been added to the pier base, bringing it up to its final height. The open cutout in the floor is for steps.

The walls have been studded up. The Ash dome manual I’m using shows a supplied dome base ring that went on the top of the wall for mounting the azimuth wheels, but I didn’t get a ring with this dome, so I had to make one. It’s cut from 3/4″ plywood in 4-foot sections. It is actually two rings stacked and glued together to make a single ring 12′-2″ in diameter and 1-1/2″ thick. In the photo the ring is painted black to seal it up in case of rain.

Some of the 2″X6″ wall studs had to be tweaked to ensure the building was as round as possible, and then 1/4″ exterior grade plywood was installed. Also in the picture, a concrete pad was poured in the entry way and the door was framed with pressure treated lumber. The ring on top was installed according to the Ash manual, being leveled with shims and bolted to the top of the wall with 1/2″ carriage bolts.

The metal siding was leftover pieces from the roof of the log home we built in 2018, and sold before moving here. It got kicked around for about five years, so it has its share of scratches, but it saved me money.

The plastic vapor barrier covered with gravel has now come back to haunt me. It was a very hot summer, with temps hitting a hundred on a regular basis, and my Australian Shepard liked to lay under the floor on those hot days, while I was sweating away up above. Unbeknownst to me, he dug up the gravel, and the plastic barrier, in multiple spots while making himself comfortable. So I finally admitted I should have poured a concrete floor and set about fixing it. I had to rake out the gravel, trim up and repair the vapor barrier, and lay in more cut up cattle panel for rebar , before then pour a concrete floor. Not an easy task at all now that the wooden floor was installed. I also cut an access hole in the floor to make getting in there easier as well. I should have poured concrete from the very start, but was trying to save money.

The dome rotates on twenty-three garage door rollers. I can’t remember now why twenty-three, but that may have been how many mounts were in the box. The rollers I’m using are 3″ polypropylene commercial rollers with sealed bearings and stainless steel shafts. The wheel mounts are galvanized and came with the dome, but had sat in a box for probably twenty years, and were heavily oxidized. Before installing them, they were cleaned and coated with cold galvanizing compound. Also, under each mount is a 1/4″ thick neoprene rubber pad. After test fitting, the mounting holes were drilled through the base ring for 1/4″ bolts.

A lot of the dome’s hardware was missing, and what was there was mostly corroded, so I ordered all new stainless steel hardware. So far I’ve ordered over 600 screws and bolts, plus nuts and various types of washers. I’ll order more later as I need it.

The dome’s base consists of six segments. This base ring had been previously assembled and drilled for bolts, but none of the segments were marked, so I had to sort them out by matching up bolt hole patterns. Five of the six slid right onto the rollers, but for the last piece I had to remove and mount the wheel track first, then slip the segment in from above and bolt it back together. The braces, gear track, and wheel track for each segment were already installed when I bought the dome, but I replaced all the old hardware with new stainless steel.

This is a day I had long awaited, actually assembling the dome panels. On the first day of panel assembly, we (my wife helped) only managed to get 8 panels mounted because of all the prep work. A Lancaster dome has a steel ring in the top to tie all the panels together, and it has to be supported until a sufficient number of panels are added to make it self-supporting. That’s why all the wooden blocks are stacked on the ten-foot step ladder. The only hurry here is to get all the panels installed before any windy days come along.

We hoped to finish installing panels on the second day, but didn’t quite get there. We’re getting faster as we go though, at this point we have 21 panels on.

The third day and all the panels are in place. The remaining gap in the panels is where the shutter opening will be cut out. The ring in the top will also get cut out. This dome is a lot more hands on than a pre-cut, pre-drilled kit.

A look inside the dome reveals all the dome clips tying the panels together. These are zinc-plated and had also been oxidizing away in a box for twenty years, so they were coated with cold galvanizing compound as well. I was also short about seventeen clips, but I discovered Virginia Silo Company was less than two hours drive away and they not only had the clips, but gave them to me without charge. Kudos to Virginia Silo.

Finishing touches on the inside include a railing around the stair well, to prevent anyone from accidentally falling into it, not that I would know anything about that. Let’s change the subject. All the material for the railing was leftover from our front porch and rear deck projects on the house. The walls were lined with reflective bubble foil before installing Luan paneling.

The entry and stairs have also been finished up. It’s two steps (three if you count the floor) up to the wood floor. The stairs are open underneath so no creepy crawlies have a place to hide. Panels were installed to close off the under-floor area, but a vent was added for air flow. The rails and steps will be finished with Australian Timber Oil. The door is not a standard size, it’s approximately 69″ high and 31″ wide, so one was custom made instead of trying to chop up a prefab door.

To finish the pier, the base was filled with concrete and rebar was added. I also installed a short conduit from the side of the pier under the floor up to where the metal pier bolts on top.

The concrete on the square pier comes up level with the subfloor and then transitions to a round base. It will be less of a trip hazard than having square corners jutting out. The round form was made from a large plastic planter from Tractor Supply. It was cut down to 7-1/2″ high, which makes the final pier height of the steel pier 60-1/2″. Galvanized J-bolts were set into the top for attaching the metal pier.

The finished base was allowed to set up for a couple of weeks before installing the heavy metal pier. Also, now that the forms have been removed, there is a gap between the floor and pier base, to prevent vibrations being transmitted to the pier. The base is also isolated from the concrete floor below, but the gap there is filled with foam to keep critters and moisture out.

I guesstimate the metal pier weighs at least 150 to 200 lbs. No way I’m picking that up by myself, so I lifted it into place with a chain winch hanging from a wooden beam supported by two ladders. The pier is adjustable from about 39 to 42 inches high, the center pipe is 10″ in diameter and is 3/8″ thick steel. The top plate and bottom plates are 1/4″ thick. The adjustable top plate and bolts are not yet installed.

Ready for paint. The pier has been set, the walls are installed, the entry way is done, and the floor sanded. I even built a curved table out of leftovers, that fits tight against the wall. The open panel beside the table is where the cables from the pier come up from under the floor. That panel will get installed later.

And now there’s paint. I call it star chart blue, but Benjamin Moore calls it New York something or the other, I forget. I also have a black rubber floor to put down once the dome’s shutters are finished and all the ladders are gone.

I noticed an issue with the dome randomly rubbing on the wheel ring as it rotates, due to play, or runout, in the wheels, and also possibly the dome not being perfectly round, too. So, I added four horizontal anti-runout wheels around the wheel ring. This is also how my Exploradome handles this issue and it completely eliminates the rubbing.

As previously mentioned, I was missing all the spacer blocks for the outer shutter track supports. The Ash manual showed ten blocks on each side. I made replacement spacers from 1-5/8″ round aluminum stock and each block is more or less unique, so measuring, cutting and installing them was a bit tedious. I also placed an 1/8″ neoprene sealing washer under each one. I ended up with nine spacers on one side and eight on the other because the ridges on my dome are a different style from Ash’s, and are a little larger and less symmetrical from side to side.

An example of the support blocks installed on the dome. It’s also shows how the ridges can get in the way of installing the blocks. Because of the difference in these seams compared to the panels Ash uses, I want to avoid drilling holes through any of them.

To custom cut the spacer blocks I purchased a table-top, metal cutting bandsaw, which made sawing the blocks a breeze.

With the outer track supports now installed, I can start cutting the opening out to its full 42″ width. In the photo the top section of the opening has not yet been cut out, because my 4-1/2″ angle grinder is too small to cut through all the closely spaced ribs on top along the rails. I ordered a 6″ angle grinder for this task, but while waiting for it to arrive, I’ve begun installing the inner curved, right-angle flashing around the opening.

The last pieces of the panels have finally been cut out of the shutter opening. The panels were removed using the new angle grinder with a cutoff wheel. Now the remaining flashing can be installed, and the seams caulked.

The next big step is installing the shutter tracks, once I’ve figured out how to bend them.

Two test examples of bending the shutter tracks without proper tooling. I can’t just bend the tracks as is without the use of custom dies that prevent the track from twisting or collapsing as it bends. So, I cut the top edge and the back of the tracks every four inches, down to the beginning of the curved bottom section that the wheel rolls in. This allows it to bend without causing as much twist or deformation as was happening with the uncut track. The top piece in the photo is thinner residential grade track and the bottom piece is a heavier commercial grade. The thinner track is easier to bend, but deforms more than the thicker track. I prefer to use the heavier stuff, so next I’ll try cutting and bending a thirteen foot length and see if I come up with something usable.

It may not be pretty, but it is curved. The small piece of outer track support shows the exact curve needed. The track still needs some tweaking but that can be done during the process of mounting it. First the cuts need to be dressed and the whole track painted with cold galvanizing compound. Also, the cuts on this track are spaced 5-inches apart. This 13-ft piece of commercial grade track is one of two that came from an old, tall garage door that was replaced at a metalworking company, and the old tracks were given to me. I had to clean off decades of caked-on grease, but they are still very serviceable. They’re not quite long enough, so another short section will be added. I’m getting very close to being able to install the shutter.

The drop down door has been temporarily installed to see how things are lining up, and to mark a starting point for the tracks. It will have to come off again before installing the shutter.

The shutter tracks are bring installed in the photo. As soon as these are on the shutter can be put in place.