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About Rusted

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  • Interests
    ATM, imaging, Solar system, photography, blogging, cycling.
  • Location
    Darkest rural Denmark
  1. Hi Just another heads up to say that dome rib production is well underway. These will be reinforced with sandwich battens on their outer edges. Then clad with trapezoid, plywood panels rather than conventional gores. The idea is to break up the dome's outline with facets to present a [hopefully] smaller "blot." Paul Robinson's Geo-Dome.Co.UK website may inspire: Trapezium Dome calculation tools
  2. Still progressing with the build: Veranda now planked with larch boards. Tried various mock-ups of potential rotating roofs/domes to ensure telescope clearance.
  3. Is a concrete slab really necessary? Pre-cast Carport footings/anchors are simply dropped into a hole and back-filled with soil. Inexpensive and needs no more than a spade and digging bar/crowbar if you hit rocks. Here are a few being put to good use:
  4. Be prepared to allow the farmer to choose the position and layout of your plot. He may need to get large machines or tractors and trailers around your 'obstacle.' So a strip close to your boundary may be best. Middle of a field not so much. If animals are grazed on the field it will need professional fencing and a secure access gate. We bought a triangle of adjoining land from the local farmer without serious issue. However, nothing was to be built on it and it was only landscaped as lawn. He arranged the pro animal fencers for a very reasonable sum. He kept bulls, horses, sheep and cattle in there so a strong fence was obligatory. Seriously consider discussing renting rather than purchase. So much easier for both of you. What's a crate of beer between friends? Above all, be flexible.
  5. Double Walled Observatory

    My own experience is that metal roofs make a racket in heavy rain. We stayed at a farm with a corrugated metal porch across the yard and it was dreadfully noisy! I clad my home-made shed in 12mm plywood [with factory machined grooves at 4" intervals] 14 years ago. I haven't touched it with any sort of paint or protection from new and it is still fine. It has remained flat, strong and quite attractive if you like the grey/brown [long abandoned building] "knotty pine, weathered" look. The shed has decent ventilation but wood and plywood stored inside gets spotty and my iron tools rust slowly. My fuzzy logic suggests that insulating an observatory will delay cooling and retain any daytime heat buildup. Shiny aluminium remains the coolest useful surface material I have tried so far. Shiny stainless steel and galvanized iron temperatures absolutely soar in warm sunshine! Only new, white, fiber cement roofing & cladding boards are cooler if you can manage the weight and relative fragility. Roofing felt is by far the worst material on the planet for obs. roofs. IMHO. Not only is it very heavy, but temperatures inside soar as you would expect with a dull, black and rough, solar absorbent surface. I built a fairly large workshop with a felt roof on plywood and recorded 103F with the doors and windows wide open! When I covered a 4-6" thick, concrete slab, shed roof, with recycled aluminium sheet, it made it instantly habitable as a workshop. With the original black felt covering it regularly went up to 100F inside, day and night for ages, after hot sunshine. My only experience with white paint was two thick undercoats on a bare, GRP car. That made it cooler in sunshine. Though the windows probably dominated in solar gain. Titanium white paint has a good reputation for rejecting solar gain. Dense shade plants are probably even better provided you can still find the sky. Big pots of shading/concealing plants can easily be moved/rolled/sack-trucked away when needed. Louvered/slatted blinds must have some useful purpose for shading/ventilating an obs. All the sunshine which never reaches a building never needs to be rejected/reflected, AC'd or insulated against. Not a lot of architects, builders, engineers and/or planners seem to know this.
  6. Building an Observatory DIY

    Hi Lars The wind drag on a structure increases as the cube of velocity. Your building might seem safe in a breeze but a gale will quickly move it to Norway, Denmark, Finland or even Russia. Anchors and steel cable guy lines might help if the structure stays together in the first storm to hit it. During the Great '99 storm in Denmark the wind speeds reached only 35m/s. It ripped solid brick and block buildings to shreds, removed whole roofs and damaged thousands of others. It snapped off vast swathes of conifer forest half way up the trunks of the trees and felled lots more. Our neighbour's corrugated steel, double garage roof had been there for years. It was rolled up by the wind and thrown 200 yards over the intervening houses and 50' trees. It ended up half buried in a field behind a farm which looked as if it was hit by a very large bomb. Adding weights wont help. It needs fixing down! Yes, I live in Denmark but I'm British and hoping to remain in exile.
  7. Building an Observatory DIY

    Hi Lars Did I miss the picture of where you anchored the observatory down to stop it blowing away? You could drill the rock and embed studs [threaded rods] in the special adhesive designed for this purpose. BTW: Don't trust the lightweight tarpaulins [presenning] if you want real waterproofing. The heavy PVC tarpaulins are much safer. Or, you could place an inverted PVC water butt or barrel over the mounting and pier to protect when not in use. Regards/ Med venlig hilsen Chris
  8. Hi, Thanks for your interest in my project. It all helps to keep me going. Here's another image taken yesterday after I trimmed and fixed the obs. floor. I had to be careful to isolate the 12' tall 4x4 pyramidal pier posts from the floor. Boarding the veranda is next. Each section will run parallel with the octagon sides. Then I shall need outer railings for safety. And a dome, or rotating roof, of course.
  9. Hi Just another update: I have the DIY heavy mounting up on the 12' pier and the 7" f/12 refractor mounted. Busy cladding the pyramidal pier with plywood for extra stiffness. Working alone, I had to use opposed builder's stepladders to lift the massive 250lb mounting into place.
  10. Just another progress update: My isolated 12' high pier is now a four sided pyramid of timber 100x100mm [4x4s] bolted to carport concrete anchors/footings. The top part will be sheathed in plywood and timber braces down below for extra stiffness. My Jumbo 'warehouse/stores' obs. access ladder has arrived. All aluminium, with stainless steel handrails extending 1m above the top tread at obs. floor level for easy transition. The top tread is exactly at obs. floor level. Solid as a rock, it will eventually be resting on large paving slabs. Now I have the ladder I can start fixing the 125mm [5"] planed, larch floorboards to the obs. floor. The pyramidal pier required re-siting some of the original obs. floor joists.
  11. Progress continuing: Main structure almost complete. Now fitting larch floorboards. The view is amazing!
  12. Just an update: I have temporarily fitted my first, doubled 2"x8" beams onto their timber brackets. I still need to glue and bolt the brackets into place. Presently researching a suitable "glue".
  13. All eight vertical posts and perimeter joists completed. It is remarkably stiff considering it is just an outline shell. No problem supporting a ladder on any upper component. Now to add some more joists.
  14. Despite the hot weather [66F] I managed to raise five more posts and brace them with the perimeter joists. Now seven: View from upstairs window:
  15. Trial erection of my first two 4m [12'] posts to check safety and working methods using lashed stepladders. Each new post is raised and leaned against the ladders' top cross brace until it can be brought upright and tied to the ladder. Then I will add the 2" x 6" perimeter joists to tie the octagon together. Then the ladders are moved onto the next post and the addition of joists repeated. Timber braces will aid the stability of the structure until it is completed.