GardenAstronomy

My Observatory

My back garden is quite large and has a gentle downward slope.  This causes an 'engineering' problem whenever a flat area is required.  Over the course of the 12 years I have lived here I have created various such areas - for the greenhouse, a patio area and latterly one for when I started observing.  And ever since the greenhouse was erected I had been trying to create a flat area in front of it on which to put plants out to harden off, etc.  But the actual act of creating the greenhouse platform had meant that there was relatively large slope in front of it.  And all the rubble I had collected from an old coal bunker and other places had really only created a rather large uneven heap.

 

Fortunately, at the time of deciding I needed an observatory we were also doing some other building work around the back of the house.  So I asked my builder to also level off the bit in front of the greenhouse and create a sufficiently large platform beyond that for the observatory.  This he did - very well - so that I now had a nice 10' x 8' platform immediately in front to the greenhouse and a further good-size platform stepping down 9" or so to where I would put my observatory.  Perfect.

 

All the while this was going on I was waiting for delivery of the observatory from Pulsar Observatories.  I had actually paid a visit to their shop in the previous summer and had a brief look, but being quite some time ago I didn't have that clear a memory of it.  With a waiting period of some 8 to 10 weeks, which stretched out due to the intervening Christmas holidays, it did at least give the builder plenty of time to finish the base.  And with the continual wet weather he needed that time.

 

During the wait I had signed up to a course with the Liverpool John Moores Institute - The Universe through a small telescope.  Unfortunately, the weather was so bad that all of us, even those not in the UK, were struggling to even get started.  Good though the course is I decided in the end to do it 'privately' once I had my own observatory as the qualification wasn't something I was seeking - merely the discipline and knowledge gained from it.  But more about that later.

 

The observatory I had ordered was the 2.2m full height observatory, plus the rubber flooring.  Sufficient for my modest needs and able to take up to 12 inch scope - allegedly.  At the time I had just the 5 inch Skywatcher Newtonian Reflector but was looking for something larger and spent many 'happy' hours browsing through the web looking at all the options.  Whilst this was going on some friends of mine were in the process of installing their second-hand home-built observatory ready for the massive 14in Newtonian that they had purchased.  As they also had another 10in Dobsonian they were ready to part with their 6in Celestron NexStar.  So, after a lot of heart-searching, and bearing in mind the large sum of money I was spending on the observatory, I opted to save money and buy this from them.  

 

Was it the right choice?  Well, although just a modest step up in aperture it was a GOTO and compact, unlike the Newtonian.  Being rather ancient I find the business of standing for any length of time and contorting myself into various horizontal and vertical positions decidedly uncomfortable - and my back was playing up anyway.  It also included a dew strip heater and Michael Swanson's 'The NexStar User's Guide', which is an absolutely brilliant book which I would recommend to anyone, whether they have a Celestron NexStar or any other GOTO make.  

 

So I was all setup and ready to put up the observatory.  This duly arrived and was loaded into the end of our garage.  All I needed now was a clear couple of days to put it up and these were not too long in arriving.  Fortunately for me I have a very good neighbour, a retired engineer whose garage and workshop is an absolute Aladdin's cave of tools and equipment of all kinds.  It was he who took charge of the business of putting it up, together with another neighbour and eventually with several others called in to lift the dome into place.

 

As with all such endeavours, nothing is ever perfectly straight-forward.  Developments and improvements are made to all equipment and the associated instructions are usually the last things to be updated.  Most of it was fairly straight-forward until we came to the pulley system.  This had allegedly been improved and the instructions didn't tally with the equipment.  Fortunately my engineering friend sussed it out, for which I am eternally grateful.  I am not completely sure that we have got it 100% - it works though I keep a watchful an eye on it.  But everything else went fairly smoothly even though it took us at least twice as long as the manual stated.  The dome rotated smoothly, the door fitted nicely, it looked good and all I had to do was put down the flooring, apply extra silicone sealing round the base and install the scope.  All managed without too much hassle.

 

Unfortunately the weather changed after that.  This turned out to be useful because on opening up the observatory after one particularly heavy storm there were pools of water on and below the rubber flooring.  This was very puzzling as there were no obvious leaks in the roof or around the dome and the rubber flooring was laid on top of a waterproof membrane.  

 

To cut a long story short, the problem was that the door faces the prevailing winds and the heavy Welsh rain was being blown into the gap above the door, and also down the hole where the door bolt fastened into the dome itself.  The solution was to attach strips from the remaining flooring off-cuts on to the dome above the door and down the sides, and apply a bit more silicone sealant, together with a bit of vaseline around the door bolt.  It worked well until the weather decide to give us horrendous horizontal driving rain and the floor really did get flooded - see below.

 

So the observatory was now in place, it looked very good and was ready to use.

 

Postscript.  This problem with Pulsar observatories is undoubtedly a design fault as other purchasers have discovered, particularly in the wetter areas of the UK.   The door opening needs some form of lip or 'porch'  and some sort of return on the door recess + seal.   Also, DON'T position the door so that it faces the prevailing winds as I did.  I now try to remember to position the shutter so that it overhangs the door when not in use.  And I will probably attach something to  the shutter to overhang the door to further protect the door opening.  The SkyShed pods seem to suffer from the same leakage problem, but the Sirius domes which come from Australia and are much more expensive, seem to have addressed this problem.

 

One further problem that applies to all types of observatories is CONDENSATION.  In an unheated building of any kind this will occur.  So you either go in for some form of dehumidifying equipment - expensive - and/or some further form of protection for your scope is necessary.  I now have use a Telegizmos  telescope cover and inside it I keep a number of Silica Gel packets - but see later.

 

August 2014:  After 3 coats of AquaPrufe applied to the floor, plus a pond liner and the original liner supplied by Pulsar I hope I can safely say that the inside is now dry, and remained so even after the recent 1 - 2 ins of rain.  And no sign of algae inside though still need to be removed from the outside.  (It didn't work - water still pouring in somehow!)

 

October 2014:  Further cheap rubber draft-proofing around the top and side of the door seems to have created further protection against driving westerlies.  And I am now leaving the scope 'unprotected' inside the dome as putting a cover on it merely seems to increase the condensation on the scope under the cover.

 

October 2015: The Welsh weather means that Telegizmo cover merely traps condensation inside the cover, so that has been dispensed with.  And I no longer position the shutter over the door entrance - if the weather is wet and windy that merely seems to increase the amount of rain blown in at the door.  Still haven't figured out a proper solution to that though the amount of water inside due to that when it happens is quite small.  But one big improvement has come about with the use of ACF15.  This was bought from a motor cycle shop and I have sprayed it over the counterweight shaft and the weights and the pier and any nuts and bolts and electrical contacts that I can see.  Everything looks better though the shaft still shows some rust spots, but everything should be protected for another year.

 

Nov 2016: I got fedup with constantly drying out the observatory floor and decided to relocate it. This involved dismantling it into 2 sections, the dome and the walls. The whole observatory was rotated slightly so that the door no longer faces the prevailing winds - and makes it much easier to get in without bumping the scope - and move forward about 18 ins so that it was further away from the hedge. A 8mm gasket was put under the walls and a 4inch high 60cm diameter plinth added in the centre.  All in all a big improvement.

 

 

 

IMG_0450 IMG_0451 My Observatory

Top half ready to be lifted on to the base

Bottom half which is actually level - just the photo which is wonky!