Astronomy Log

Once the pent shed was erected, I then considered the insulation and the types of products I could use.

I went for 50mm polystyrene sheets which measured 8ft x 4ft, again I ordered these from Buildbase as they were a lot cheaper than Travis Perkins, at around £7.50 each inc VAT.

I also ordered some sheets of 6mm Plywood at the same time, as I wanted to cut the polystyrene sheets into the recesses of the shed and then have the plywood over the top. The plywood was the most expensive item at around £14 for a 8ft x 4ft board.

I ended up ordering 7 sheets of both, with the polystyrene cut and fitted, I had one board left over, so I actually only needed 6 sheets for the 8×6ft pent shed.

Cutting the polystyrene sheets was quite messy, and the garden now resembled in parts a snowy type of winter wonderland scene, with all the residue of the polystyrene balls everywhere. I actually cut the sheets with a saw, and it was really easy to do.

The only problem has been that the shed recesses are 40mm deep and the polystyrene sheets only come in 25mm and 5omm depth, so I now have the polystyrene sheets sticking out by 10mm.

To get round this I could have either thinned down the sheets, but a very messy job. I did think of cutting up polystyrene strips in 10mm depths, but again probably a difficult and messy job.  So I ended up cutting strips of plywood for one inner wall. I actually used 2 pieces back to back to layer up to the correct height.

On the other three inner walls I used some rough wood which came from Travis Perkins pallets, the wood actually spaces the main wood on the pallets. It was the correct width and depth, and they nicely let me take as much as this as I wanted.

So far I have insulated the whole of the shed including the door, but excluding the ceiling, I may insulate a part of this when I work out how I am going to have my roof open up, I may also insulate the main part of the ceiling with a thinner lighter silver reflective sheet, but we’ll see.

I found the Celestron FirstScope whilst on my travels around the web, and it looks like a well built mini tabletop telescope. It’s actually a mini Dobsian Reflector Telescope with a 76mm aperture and a focal length of 30cm.

The write up says: “The FirstScope is a wonderful keepsake for anyone interested in astronomy. This quality Dobsonian style telescope features a 76 mm aperture reflector optical tube. The compact design makes it easy enough to take with you on your next outdoor adventure. FirstScope is also stylish enough to be a decorative fixture on your bookshelf or desk”.

Celestron FirstScope Features:

• High quality Dobsonian style stand with a 76 mm reflector optical tube make FirstScope an ideal entry level astronomical telescope.
• Portable and lightweight table-top design makes it easy to store, transport and setup your FirstScope Telescope
• FirstScope is very easy to observe with, the user simply navigates the night sky by moving the tube in the direction of their desired object.
• Stylish and decorative design makes FirstScope a wonderful keepsake for anyone interested in astronomy.

Official Product of International Year of Astronomy 2009!

Named Official Product of International Year of Astronomy 2009, FirstScope pays tribute to the men and women who brought us one step closer to understanding the universe around us!

In 1609, world-renowned Italian scientist, Galileo Galilei, introduced an elementary telescope to the growing astronomy community which sparked interest into the mysterious night sky for centuries to come. Four centuries later, in celebration of the International Year of Astronomy 2009, Celestron offers the portable FirstScope Telescope. The FirstScope pays tribute to Galileo Galilei and many of history’s most notable astronomers and scientists by displaying their names around the optical tube. We honor the contributions of these men and women, who brought us one step closer to understanding the universe around us.

FirstScope Specifications

Optical Design: Dobsonian Reflector
Aperture: 76 mm (2.99 in)
Focal Length: 300 mm (11.81 in)
Focal Ratio: 3.95
Eyepiece 1: 20 mm (0.79 in)
Magnification 1: 15 x
Eyepiece 2: 4 mm (0.16 in)
Magnification 2: 75 x
Weight: 1956.12 g

FirstScope Warranty

2 Years

You can buy the Celestron FirstScope at MyMemory for £54.99 inc Free Delivery.

Saturday I finished off the slab laying and painted the shed some more, to give it two coats all over. Sunday my father came to help me in the afternoon erect the pent shed, as this is definitely a two man/person job.

We began by marking out where to cut the hole in the base of the shed to leave the space for the pier. We then re-inforced the underside of the shed base with extra wood battens which I purchases separately. We did this because once we had cut a hatch in the floor, the floor lost a bit of it’s strength especially when walking near the edges of the hole.

This part actually took the longest time, as then we put the back of the shed on first, together with a side, and then the other side, and the front, all of wich went up quite quickly.

I was amazed at the actual height of the shed, I had ordered it to be 1 foot taller at the back and front, and I was worried that the Telescope won’t even see Polaris or anything else for that matter. Anyway next came sliding the roof on and then we put the felt on the roof, but perhaps next time I may put the felt on the roof before we put it on.

Then it was time to finish for day, I had left it water tight, whilst I decided and designed how I want my roof to open. Although there are still lots of jobs to do, including fixing the corner external vertical battens, putting in the windows, filling any holes, putting on the electric, touching up any bits I missed with the stain, and also get the shed lined and getting plywood put up, it’s not over yet!

Saturday morning I carried on mixing cement and laying the slabs. At about 11am I had a break and went off to my local tool hire shop where I hired the SDS Drill and 110V to 240V converter to make the holes in the concrete for the pier bolts, which cost about £19 for the weekend.

I also called into ScopesNSkies where James lent me an 18mm drill bit for the pier holes. I had previously been into ScopesNSkies during the week to purchase the Pier Fitting Kit, which consists of 4 bolts, washers and nuts, you get the tube of resin included, but you will have to remember to get a metal gun for the tube of resin.

Once I got back home, I drilled the 4 holes in the concrete. I was very worried about not making the holes in the correct place or drilling them at an angle. So I drilled one at a time then moved the pier into place and re-checked the other holes and re-marked them again.  A lot of concrete powder came out of the ground when drilling the holes, and I was advised to use my hoover to suck out the dirt left in the drill holes, as they need to be as clean as possible when putting in the bolts and resin. So I began looking for a piece of hosepipe to tape to the hoover attachment, but the hose pipe was too large to fit the drill holes, so instead I used a plastic tube which comes with those expanding foam cans.

I now needed to set the bolts in the holes with the resin in the kit, but I did not do this straightaway, I actually left it until the whole shed was put up.

It was now the weekend again, and the concrete has been left about a week to set. It was now time to lay the slabs for the base of the shed. All week during the evenings I have also been staining the shed. In the end I managed two coats on all sides of the shed, but boy I wish I had ordered the shed pre-treated, it may have cost a little more, but it would have saved me a lot of time.

I began the weekend by making a couple of small purchases late on the Friday night, firstly I purchased some Bitumen weatherproof gunk, to paint onto the concrete pier base, as I was worried about water sitting around the base of the pier. I also purchased a small tube of Ronseal Wood Filler to fill any holes in the shed where the knots had fallen out.

I had ordered 8 bags of sand (4 Sharp and 4 Soft) as well as 2 bags of cement for the 11 slabs I was laying.  I was worried I would not have enough sand, and all the builders merchants close at noon on Saturday near me, so may last chance to get more was around 11.45am (even though in the end I had 2 bags spare, so only used 6 bags). So because of this Friday night I laid 3 slabs just to work out how much sand and cement that had used, but it seemed I had ordered about enough. 

I finished off laying the slabs on Saturday (the next day). I actually purchased the cheapest slabs I could find which are Council slabs in grey, these come in two depths, but I went for the thinner ones as these are already heavy enough anyway, and the 600mm slabs are quite awkward to work with compared with the smaller 450mm slabs. I paid about £3.50 for the 600mm Council slabs from Buildbase. I ended up hand mixing the cement I needed to fix the slabs down in a wheelbarrow as then I could mix about the right amount everytime for one or two slabs.

Things are still pressing ahead around normal paid work and looking after my son. But today I had the shed delivered and the slabs, sand and cement from Buildbase. Whilst unloading the van I remembered just how heavy the 600mm concrete slabs really are and how they will break my back when I come to lay them out. I usually use the smaller 450mm which are a lot easier to handle, but their size this time just did not fit the plan.

I ordered the shed untreated, so visited Wilkinsons to buy some stain the other day, I nearly purchased the Cuprinol brand, but at £15 for 5litres, I went for the Wilkinsons own brand which looked just as good for £6.99 for 5litres. In the end it’s probably the same stuff and probably made by cuprinol for Wilkinsons anyway.

I painted a few sides of the shed tonight before it got too dark to see, but I think I will need a couple more 5litre tins of “English Oak” before I am finished, especially if I am staining inside and out and giving the bottom of the floor several coats.

I think next time I will get the shed supplier to treat the shed for me before delivery, saving me a bit of time, as they charge 10% of the cost of the shed to treat the shed, which would have been around £35-£45, a little more costly than doing it yourself, but probably worth it.

Today the hole was filled by an AnyMix concrete mixer. I spent a while looking into how to fill the hole, whether to manually mix the concrete myself and hire an electric cement mixer and order in the cement and bags of ballast.

But after using some online concrete calculators I discovered I actually needed 2x 1ton bags of sand and possibly something like 13 bags of cement. This price came to about £160 with the hire of the cement mixer, I thought it would originally cost me about £70 to do it myself, but a 1 cubic metre needs more aggregate than I thought.

The 1 ton bags of sand were not too bad price wise, as BuildBase sold them for about £45 each. Anyway I then decided to call around concrete companies and get some prices.

At the time I did not really know what mix type I wanted, as it all seems a bit confusing to me. James at ScopesNSkies recommended a 3 to 1 mix, so (1 cement, 1 gravel, 2 sand).  I was told by some companies that this may be too rich, as adding too much cement would mean the block would crack.

So in the end I got prices for a C35 mix type, although Hanson advised a fibre mix with hair in it.

Hanson quoted about £250, Cemex quoted £206, Tarmac would not deliver to my area, and finally AnyMix originally quoted £167, but after phoning back and saying I was originally quoted £150, they agreed on this price.

That was great as this price, was less than what it would cost for me to do the mixing myself, so the delivery was booked just 24hrs before, for a 3.30pm delivery.

My father and I began by building a wooden frame so aid with levelling the concrete. I bought the 2×3.6m 1″x2″ wood from Travis Perkins for about £6.50. We then also used some blue plastic liner to contain the moisture of the concrete. We actually used 2, one inside the other.

The delivery was a bit late and arrived at about 4pm, but the driver was very accommodating and friendly, and we used 2 wheelbarrows to offload the concrete.

Even though the hole was nearly exactly a 1 metre cubic hole and I ordered 1 cubic metre, we still had about 5 wheelbarrow loads left over in the concrete lorry. Luckily the driver decided to get rid of it for us, although with hindsight we could have used it for the footings to go under the slabs. But we had not thought of this and had not pre-dug the space.

Next time, if there is a next time of doing this, then I will pre-dig the footings to be ready for any over supply of concrete.

The concrete went in well, and it was a bit of hard work barrowing the concrete. My Dad levelled off the concrete with a large length of wood and now it’s drying off. Apparently it will take about 1 week to fully set.

The observatory pier base hole has been empty for a couple of weeks now, waiting for me to get my concrete order set up.

Well today I popped out to Travis Perkins for some wood for my concrete frame, and when I came back I found a hedgehog asleep in the 1 metre deep hole. Poor thing must have fell 1 metre, one evening and then settled in, although it does appear that it did try and do some digging whilst occupying the hole. I think it may have been in the hole a maximum of two days.

Anyway, I got it out by using my spade and lifting it out and taking some soil with it, as to not disturb the hedgehog.

Here is an image of the hedgehog still alseep after being set free.

I left him snoozing on the spade, but after returning an hour later he was gone.

This is day three and day four of the observatory build. My goal this weekend was to dig the cubic metre hole for the mount base. I had a 2 yard skip delivered on Friday which cost £60. I also borrowed my dad’s wheelbarrow to complete the task.

I started at about 9am on Saturday morning, and the first couple of spade lengths went really easily, but then I hit the builders rubble level, and this point nothing was going through, not the spade nor the fork. At this point I was ready to give up and visit the tool hire shop for a pneumatic hammer or drill or something! But after a bit of perseverance and actually inserting the fork and then doing a circular motion I actually made it through the rubble and stone level.

This gave me renewed motivation, and luckily by 12noon I had to stop in order to go out to a BBQ. At this point I had dug to a level of about 30cm, so only about 70cm to go!

Sunday I carried on and started at about 10am and dug for most of the day, with a 2 hour lunch break. I ended up putting the parasol and base above me to keep me out of the direct sunlight which help enormously.

I did find the digging now reasonably straightforward, as I went from brown clay onto grey clay which was a bit smelly. Throughout the digging I was also joined by a friendly blackbird looking for food, as well as a bee who enjoyed visiting the new small holes made in the sides of the hole.

So at about 5pm the hole was complete, but only after shaving a few centimeters of the sides, as my digging was not completely straight. The sides don’t measures exactly 1m, at some points it is 95cm wide, but I hope this won’t matter too much.

Next I am going to have to fill my hole with concrete.

This was the first couple of days I actually got started in preparing the observatory base. I have spent a few days browsing websites, talking to astronomy retailers and other observatory owners on the web.

I also drew up a loose plan of the observatory and what number of slabs and aggregates I required. I drew up an image in Fireworks (the Macromedia photo/paint program) which allowed me to draw lines, boxes and circles and move them all around to see what fitted.

Day One

I began my first day by moving the current shrubs in the border out of the way and re-planting them somewhere else, this basically took me the whole of day one.

Once the area was now clear, I then marked and measured out the area of the location of the shed.

Day Two

Today I took up the turf that was in the way and also measured out the central hole, where to concrete base for the pier is going to be. I have been advised by James at ScopesNSkies to dig a cubic metre for the base, so 1m wide, 1m long and 1m deep.

This is a fairly big hole, so I am considering getting a small 2 yard skip to take the soil. Instead of mixing the concrete by hand, or with a mixer, I am also going to enquire about the cost of getting the concrete delivered, then just using wheelbarrows to take the concrete to the back of the house. I have read that 1 cubic metre is about 20 barrow loads.