Helena Observatory (re)build

[KathyNS]

Today's work was pouring the concrete for the pier footing. I managed to get it all done before the day got too hot. When I knocked off at 11:00, it was "only" 27 degrees C! Hydration was a major concern, and my back is a little worse for wear. No pics today, since there is nothing to see until the forms come off.

I ended up being short about half a bag of concrete mix. @#$%!! I had no choice: I had to set my pier bolts while the concrete was still workable. The bolts are long enough that they were into the concrete that was there, hopefully enough to hold them. I will leave it to cure for several days. Once I remove the plywood that is aligning the bolts, I will see how it looks. I should be able to add more concrete to bring it up to the planned level.

[Graeme1858]

You are probably aware Kathy that you will need to scabble the surface of the cured first pour of concrete, to expose the stone, prior to pouring the wet second pour, in order to ensure you get a good adhesion.

[KathyNS]

You are probably aware Kathy that you will need to scabble the surface of the cured first pour of concrete, to expose the stone, prior to pouring the wet second pour, in order to ensure you get a good adhesion.

I didn't know that. Thanks for the heads-up.

[KathyNS]

I finished the pier foundation. When I opened up the top of the form, the pier bolts held firm. I painted the concrete with concrete bonding adhesive and then poured more concrete on top, with a couple of pieces of rebar in it. After troweling it smooth, I am pretty pleased with the result. Once this batch cures, I will be able to strip the forms.

[KathyNS]

Hurricane Lee is a distant memory. Just a bit of wind and rain, and 6 hours without power. No big deal.

What is a big deal is that I finally got my electrical trench dug. Conduit is installed. Now I have to back fill by hand. Ugh! Oh, well, progress is progress.

[Graeme1858]

Are you going to run an LV/SCADA/Ethernet conduit too whilst the trench is open?

Graeme

[KathyNS]

Are you going to run an LV/SCADA/Ethernet conduit too whilst the trench is open?

Graeme

That would be my first choice, but there is no point. There is no possibility of getting Ethernet out to the observatory. I really, REALLY don't want to dig up the driveway. I was able to take power from the toolshed/workshop, but it doesn't have Ethernet. I will have to make do with Wifi.

[KathyNS]

Hurricane Lee is a distant memory. Just a bit of wind and rain, and 6 hours without power. No big deal.

What is a big deal is that I finally got my electrical trench dug. Conduit is installed. Now I have to back fill by hand. Ugh! Oh, well, progress is progress.

P1190467-1000px.jpg

I wimped out and got the backhoe in again to backfill the trench. My wallet hates me, but my back is happy.

I pulled a cord through the conduit, so it is ready to install the electrical cable. To pull a cord through conduit, use a shop-vac duct-taped to one end of the conduit to pull a thin string through it. Then use that to pull the working cord through. Finally, use that, and a generous amount of cable lube to pull the electrical cable.

Next will be a load of gravel for the base, and then a crane to lift the building into place.

[SparWeb]

Are there threaded studs in the "cover" (to the left of the hole casing in your photo)?

[KathyNS]

Are there threaded studs in the "cover" (to the left of the hole casing in your photo)?

The threaded studs are anchored in the concrete. What I assume you mean by the cover is the plywood panel that I used to align the bolts while the concrete set.

[JayTee]

I finally got my electrical trench dug. Conduit is installed. Now I have to backfill by hand. Ugh! Oh, well, progress is progress.

I wimped out and got the backhoe in again to backfill the trench.

After I filled in my trench (150'/46m), 12 months of weathering now shows a definite depression (a dip) where that trench is located! I should have mounded the dirt higher to allow for this.

[KathyNS]

I finally got my electrical trench dug. Conduit is installed. Now I have to backfill by hand. Ugh! Oh, well, progress is progress.

I wimped out and got the backhoe in again to backfill the trench.

After I filled in my trench (150'/46m), 12 months of weathering now shows a definite depression (a dip) where that trench is located! I should have mounded the dirt higher to allow for this.

That is good to hear. Mine is mounded up a couple of inches, so hopefully, it will flatten out.

[SparWeb]

Are there threaded studs in the "cover" (to the left of the hole casing in your photo)?

The threaded studs are anchored in the concrete. What I assume you mean by the cover is the plywood panel that I used to align the bolts while the concrete set.

Yes, that's what I was getting at, thanks for confirming.

[KathyNS]

I am going to feel this tomorrow! 3.5 yards (about 4.5 tons!) of class-A gravel, shovelled, raked and boot-stomped level. If we get a little rain, it will set up nice and firm. This is the same foundation system I have used in the past, and it worked well.

I have a crane booked for the end of the week (next week if there are weather delays) to lift the building onto the pad. Then, finally, I will be able to start moving in.

[messier 111]

I am going to feel this tomorrow! 3.5 yards (about 4.5 tons!) of class-A gravel, shovelled, raked and boot-stomped level. If we get a little rain, it will set up nice and firm. This is the same foundation system I have used in the past, and it worked well.

I have a crane booked for the end of the week (next week if there are weather delays) to lift the building onto the pad. Then, finally, I will be able to start moving in.

100_0054-1000px.jpg

Are you still on your schedule?

[KathyNS]

Are you still on your schedule?

Schedule? There hasn't been a schedule for months! My current target is that I'd like to get it done before it is too cold to work outside. But it's a very flexible target. Before this, I wanted to get it done in time for the nice fall weather. It'll be done when it's done.

At least I am making progress right now. The next step is the big one.

[SkyHiker]

That gravel should also provide good drainage should any water get in.

I see you have rain gutters around the perimeter. Was water getting through the cracks in the corner without it?

And what are those orange objects, are they anti-burglar motion-activated lights? And those grey boxes?

Sorry if I ask too much, I'm just curious about all these things that you clearly put a lot of thought into.

[KathyNS]

That gravel should also provide good drainage should any water get in.

I see you have rain gutters around the perimeter. Was water getting through the cracks in the corner without it?

And what are those orange objects, are they anti-burglar motion-activated lights? And those grey boxes?

Sorry if I ask too much, I'm just curious about all these things that you clearly put a lot of thought into.

The gutters originated at the observatory's first installation. There, I didn't make a gravel pad because there was already a bocci court in the back yard. Instead of gravel, it used crusher dust - basically class-A without the stones, just the dust. It was a very firm base, ideal for the purpose. (Like class-A, the fine material acts as a cement.) However, drips from the roof were causing little craters in the dust surface. Rather than wait for the base to erode, I installed the gutters and directed the water away onto grass.

The orange objects are junction boxes for exterior lights, with the lights temporarily removed for transport and the openings covered with red tape to keep the walls waterproof. The exterior lights are full-cutoff fixtures with red bulbs, for when I want to set up another scope on the field.

The gray box on the left-facing wall is an outdoor electrical outlet, for when I want to set up on the field. The gray box on the right-facing wall is a junction box for data and 12-volt power cables to the rain sensor and sky camera. Both those devices were temporarily removed from the exterior for transport.

This photo shows the sensors and one of the lamps.

(No problem asking. I love talking about the observatory.)

[helicon]

Looks like you are making very good progress on a very cool observatory Kathy. Curious if the gravel is going to be the surface or if you are pouring concrete over it. I guess there could be pros and cons to either.

[KathyNS]

Looks like you are making very good progress on a very cool observatory Kathy. Curious if the gravel is going to be the surface or if you are pouring concrete over it. I guess there could be pros and cons to either.

No concrete. The gravel will be the surface. Concrete is both expensive and unnecessary, plus I would then have additional drainage issues to worry about. Gravel will give me a firm base, which is all I need. It drains well. The building has a wood floor that will be well above the gravel, so I don't need concrete as a walking surface.