My Dome Leaks Home

I have had rain come into my dome.  Here I will explain how I think it got in and what I have done about it.  There have been two penetrations be different routes.  I will explain the more serious one first, and the second one in part 4 below.

This shows a sketch of a vertical cross-section of the dome through the shutter.  I must emphasise that this is not to scale and is purely diagrammatic.  The rain undoubtedly came in through the gap at the top of the dome between the dome itself and the shutter.  At its lower end, the shutter is secured closed with a pair of clips that hold the shutter closer to the dome than it may appear in the diagram.  The ropes that open and close the dome are connected at the top and were very wet and the pattern of water splashed on my desk and the floor left little doubt that that is how the rain got in.  The overlap of the shutter is about 55 mm, and the vertical gap about 15 mm.  However in strong winds the shutter rattles indicating that the wind can lift this end of the shutter (the other end is held closed by the clips that keep it shut) and the maximum the shutter can rise is to about 30 mm.  What I believe happened was that we got heavy rain with a strong wind blowing in just the wrong direction, and the water was blown up the slope of the dome and into the observatory.  It is difficult to estimate how much the dome rises in the 55 mm of overlap but, as this is near the top of the dome, the rise is not very much.

I wrote to the manufacturer to tell them about this in the hope that they had met this problem before and had a solution.  Their reply was "Our domes are water tight", which they certainly are not, and indeed their website says "Observatories are guaranteed weatherproof".  I am, however, quite prepared to accept that I may have experienced a very unusual set of circumstances, but the fact remains the rain got in.  As an interim solution I have been watching the weather forecasts and ensuring that the dome faces into the wind—that is the wind will be coming from the right in the diagram above.

After originally writing this page, I contacted the manufacturer again, pointing out the guarantee on their web site.  They have said that they are keen to resolve this problem and are ordering a rubber seal which should resolve the problem.  When this comes I shall update this page accordingly.

That was on the 12th of February.  It is now the 3rd of March and I have heard no more from the manufacturer, so I decided to implement my second idea.   I have divided the rest of this discussion into five parts.

  1. My Original Solution
  2. The Manufacturer's Solution
  3. My Second Solution
  4. A Second Ingress by a Different Route
  5. Conclusions

Home      Back to Equipment