Windy Knoll Observatory - My Build Thread

[Physopto]

I just have caught up with the last few posts here. I see you were advised to allow a vent in the top of your battery box for ventilation.

It seems that your battery box is inside a building, sealed or not, the battery needs a hydrogen vent to the outside of the building. The vent also needs to be protected by a series of fine filter meshes. I used three meshes sandwiched together in my older setup, I used a waterproof boat vent as the filter holder.

The meshes act as a protection against explosion if the hydrogen gas is exposed to a naked flame, or any kind of spark. As it is at present any escaping hydrogen gas can by the looks of it catch fire and track straight back into the battery box causing a catastrophic explosion and possibly fire or severe injury to yourself or other persons nearby. Remember you have other electronics above the battery box, a possible source of ignition.

Some years ago I had a 110Ah battery explode near me. I was extremely lucky and all that happened was some permanent hearing loss in my left ear and all my clothes were(and me) were covered in Sulphuric Acid. None of my clothes survived but a very quick shower and I was OK. It happened after over twenty years of experience in looking after all sorts of batteries.  One daft slip of concentration was all it took when I was very tired!

The way the meshes work is that they cool the flame front at each mesh. So use three causes three reductions in temperature and no actual flame passing back into the battery box. (Think of how chemists use a filter under a beaker when heating it by a Bunsen gas burner flame.)

Your set up looks great.

[Scorpius]

1 hour ago, Physopto said:

I just have caught up with the last few posts here. I see you were advised to allow a vent in the top of your battery box for ventilation.

It seems that your battery box is inside a building, sealed or not, the battery needs a hydrogen vent to the outside of the building. The vent also needs to be protected by a series of fine filter meshes. I used three meshes sandwiched together in my older setup, I used a waterproof boat vent as the filter holder.

The meshes act as a protection against explosion if the hydrogen gas is exposed to a naked flame, or any kind of spark. As it is at present any escaping hydrogen gas can by the looks of it catch fire and track straight back into the battery box causing a catastrophic explosion and possibly fire or severe injury to yourself or other persons nearby. Remember you have other electronics above the battery box, a possible source of ignition.

Some years ago I had a 110Ah battery explode near me. I was extremely lucky and all that happened was some permanent hearing loss in my left ear and all my clothes were(and me) were covered in Sulphuric Acid. None of my clothes survived but a very quick shower and I was OK. It happened after over twenty years of experience in looking after all sorts of batteries.  One daft slip of concentration was all it took when I was very tired!

The way the meshes work is that they cool the flame front at each mesh. So use three causes three reductions in temperature and no actual flame passing back into the battery box. (Think of how chemists use a filter under a beaker when heating it by a Bunsen gas burner flame.)

Your set up looks great.

Thanks for the warning & think I'll just connect a flexible hose of some sort to the round vent I already installed in top of the cooler and route it directly outside. I thought hydrogen off-gassing was less of an issue with the sealed gel batteries but apparently I was mistaken. Luckily the interface between roof and building is currently unsealed but I'll go ahead & install a vent hoae right away because I obviously don't want any exploding batteries in my nearly completed observatory!

[Physopto]

Once the battery charging voltage passes about 13.6 volts lead acid batteries start to outgas hydrogen.

That is why in the past caravan chargers are set to around 13.6 volts, for safety reasons. Trouble is the batteries are damaged by this irreversibly. The batteries life is very much shortened and capacity is much reduced ! Lead acid needs to get to around 14.4 -14.6 volts for a full charge.

I now use LiFePo4  batteries. But these cannot be charged at or below zero degrees C without  wrecking these type of batteries. Lead acid have no real problems at these temperatures.

[Scorpius]

16 minutes ago, Physopto said:

Once the battery charging voltage passes about 13.6 volts lead acid batteries start to outgas hydrogen.

That is why in the past caravan chargers are set to around 13.6 volts, for safety reasons. Trouble is the batteries are damaged by this irreversibly. The batteries life is very much shortened and capacity is much reduced ! Lead acid needs to get to around 14.4 -14.6 volts for a full charge.

I now use LiFePo4  batteries. But these cannot be charged at or below zero degrees C without  wrecking these type of batteries. Lead acid have no real problems at these temperatures.

I believe the solar charge controller charges my 200 Ah sealed gel battery to 14.1 volts before it goes into float mode which is 13.8 volts. I'm going to re-purpose an extra plastic shop vac hose I found and vent the cooler directly outside which should eliminate any potential build-up of hydrogen gas inside the observatory. I'll post some photos once the vent has been installed.

[Scorpius]

Battery box is now vented to outside.

Termination is screened to prevent insects from entering.

Enclosed on 3 sides to prevent rain from entering.

[Scorpius]

A few progress pics of control room or “control pod” as I call it since the space is quite small. By small, I mean about 5 ft. 6” (167 cm) wide x 5 ft. (152 cm) deep with a sloped ceiling 6 ft. (182 cm) at front opening and about 54” (137 cm) at rear wall. There will be two, 3-drawer file cabinets under desk which are on order from Staples -  Staples 3-Drawer Vertical File Cabinet, Mobile/Pedestal, Letter, Putty, 20"D (24871D) at Staples With cabinets in place there will be just enough room for an office chair in between however, they have built-in casters so they may be rolled out if a visitor - such as the wife - stops by to check out the imaging process or to find out where all the money has gone 🤔

So, without further ado here are the photos:

Control pod now wired and fully insulated. 2” conduit routed under floor connecting control pod with underfloor compartment adjacent to pier.

Paneling is 3/8” pre-primed, simulated wood grain OSB.

Desktop is manufactured 64” wide, 25” deep, 1 ½” thick butcher block sanded and sealed on all sides with 3 coats quick dry, satin finish polyurethane.

So, now the only items that remain on the list before pod is complete are:

Caulk joints and install molding.

Apply latex topcoat to paneling which will be off-white, or colonial white to be exact.

Install 1 string of white and 1 string of red LED rope lights powered by outlet controlled by duplex switch mounted near top of left-hand pod wall in photo.

Hang thermal blackout curtains to hold in heat and limit amount of light escaping from pod to main observatory.

Next big decision is whether to insulate and panel main observatory walls or just leave them as is so I can start using the obsy. I do not want to bring in my astronomy gear and set everything up until the major work (and mess) is complete and most tools and building materials have been moved out. What would you do?

[Scorpius]

2 coats flat colonial white latex on walls, 2 coats non-skid gray porch paint on floor and 3 coats polyurethane on desktop. Just need to hang blackout curtains and install rope lights and then control pod is finally done!!!

 

[Physopto]

Looking really good. As far as the obsy walls go I would internally insulate and board it out before you put in your gear. It will make it much less prone to temperature swings between day and night, but also much more secure.

Nice!🙂

[Scorpius]

21 hours ago, Physopto said:

Looking really good. As far as the obsy walls go I would internally insulate and board it out before you put in your gear. It will make it much less prone to temperature swings between day and night, but also much more secure.

Nice!🙂

Thank you very much! I do plan to insulate and panel the main obsy but it will probably have to wait until spring. It's been very wet this winter and the work area outside is quite muddy from all the foot traffic and that mud gets tracked back inside every time I go out to rip a piece of paneling, etc. Waiting will also allow time for my wallet to recover which is no small issue at this point and I'll finally get to use the structure and all the astro gear I've purchased for the intended purpose. Although it may not be 100% complete, it's easily close enough to use for now with the final push toward completion planned for warmer/drier weather that's only a few months away. 😃

[Physopto]

A good plan from what you have said.

But be careful when working around the astro gear when it is in place. Not trying to teach granny to suck eggs but.....

I know from bitter experience about how easy it is to stumble or slip when distracted. I have damaged several items in our house trying to speed up renovations, when I thought I could get an item in without hitting something. Worst was a kitchen cupboard door. I managed to scratch right across its front. Of course it was not replaceable, as not manufactured any more. So 9 new doors and several drawer fronts to purchase!!

I also ripped my rotator cuff in my right arm trying to do a job alone when I could have waited for my wife to help when back from work. Still not right 8 years on. 😠

 

[Scorpius]

33 minutes ago, Physopto said:

A good plan from what you have said.

But be careful when working around the astro gear when it is in place. Not trying to teach granny to suck eggs but.....

I know from bitter experience about how easy it is to stumble or slip when distracted. I have damaged several items in our house trying to speed up renovations, when I thought I could get an item in without hitting something. Worst was a kitchen cupboard door. I managed to scratch right across its front. Of course it was not replaceable, as not manufactured any more. So 9 new doors and several drawer fronts to purchase!!

I also ripped my rotator cuff in my right arm trying to do a job alone when I could have waited for my wife to help when back from work. Still not right 8 years on. 😠

 

I agree with not working around the gear and that’s why I haven’t moved anything in and continue to resist the urge to squeeze in some astro sessions when the skies are clear. When it comes time to finish the obsy walls, I’ll probably store what I can in the pod and then put the rest back in the nearby gazebo where it’s currently kept in plastic cases.

As far as body aches go you are preaching to the choir! LOL My wife will always help if I ask but I rarely do since she’s developed some mobility issues in recent years that prevent her from doing much lifting/climbing, etc. What you see in the photos was done almost entirely by yours truly with some limited assistance from family members along the way. I’ve worked construction in some capacity for 40+ yrs. and have so far learned to live with the aches and pains of getting older.

[Physopto]

3 hours ago, Scorpius said:

I’ve worked construction in some capacity for 40+ yrs. and have so far learned to live with the aches and pains of getting older.

Yup, getting old is no fun. 👿

[Swoop1]

14 minutes ago, Physopto said:

Yup, getting old is no fun. 👿

Getting old is our parents revenge for what we did to them when we were young.

[Scorpius]

File cabinets, lights & blackout curtains...

 

[JohnHWhite]

On 12/01/2021 at 02:31, Scorpius said:

A few progress pics of control room or “control pod” as I call it since the space is quite small. By small, I mean about 5 ft. 6” (167 cm) wide x 5 ft. (152 cm) deep with a sloped ceiling 6 ft. (182 cm) at front opening and about 54” (137 cm) ( all sheetmaterials I bought here  https://sheetmaterialswholesale.co.uk/ at rear wall. There will be two, 3-drawer file cabinets under desk which are on order from Staples -  Staples 3-Drawer Vertical File Cabinet, Mobile/Pedestal, Letter, Putty, 20"D (24871D) at Staples With cabinets in place there will be just enough room for an office chair in between however, they have built-in casters so they may be rolled out if a visitor - such as the wife - stops by to check out the imaging process or to find out where all the money has gone 🤔

So, without further ado here are the photos:

Control pod now wired and fully insulated. 2” conduit routed under floor connecting control pod with underfloor compartment adjacent to pier.

Paneling is 3/8” pre-primed, simulated wood grain OSB.

Desktop is manufactured 64” wide, 25” deep, 1 ½” thick butcher block sanded and sealed on all sides with 3 coats quick dry, satin finish polyurethane.

So, now the only items that remain on the list before pod is complete are:

Caulk joints and install molding.

Apply latex topcoat to paneling which will be off-white, or colonial white to be exact.

Install 1 string of white and 1 string of red LED rope lights powered by outlet controlled by duplex switch mounted near top of left-hand pod wall in photo.

Hang thermal blackout curtains to hold in heat and limit amount of light escaping from pod to main observatory.

Next big decision is whether to insulate and panel main observatory walls or just leave them as is so I can start using the obsy. I do not want to bring in my astronomy gear and set everything up until the major work (and mess) is complete and most tools and building materials have been moved out. What would you do?

Give yourself plenty of room, and gather together a good portion of patience, as well as any tools that are required for assembly before you start.

[Scorpius]

On 25/01/2021 at 09:08, JohnHWhite said:

Give yourself plenty of room, and gather together a good portion of patience, as well as any tools that are required for assembly before you start.

Plenty of room, a lot of patience and tools - got it & thanks for the tip. Btw - just noticed in your post where you quoted me there's a link to a UK sheet materials wholesaler that was not included in my original post which is very strange 🤔 ( all sheetmaterials I bought here  https://sheetmaterialswholesale.co.uk/