12.7.17

Building the Octagon Pt.48 Adding observatory wall braces.

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Wednesday 12th July.  Fewer showers today after overnight rain. After removing all the clamps and cramps from the new plywood skirt the pier now vibrates at a higher frequency over a much small movement.

I wish I was more experienced at woodwork! The first knee-height brace took 10 attempts to get the angles absolutely perfect and simultaneously the length just right. I hate wasting wood so I was determined not to make any. [And didn't] After so many journeys up and down the ladder, back and forth to the miter saw, I could then use the first example to guesstimate the rest. I haven't the strength to carry the heavy saw 'upstairs.'

Then I had to go out for more 80mm Torx screws to fix the braces as I had completely used up my second box of 100. These things are not cheap and having to fix eight of everything soon adds up.

I made a special, raised brace for the top of the ladder handrail extension. With two close fitting holes for the bare 32mm ø handrails. I used a hole saw followed by an auger bit to clean out the closed holes. Then I struggled to align the ladder so that the brace was perfectly level.

Obviously the handrails weren't perfectly aligned to start with. Which didn't help the cause. In the real world, the large, rubber end stops would have rested against the wall. Nobody would ever notice, nor care about perfect alignment. Had I chosen to use that option the ladder would have slowly crept down the wall over time. So I'm not quite the pedant you had just painted me. I wanted the ladder fixed but without drilling holes to bolt it down. Leaning the ladder against its rubber stops would normally provide the friction needed to make the handrails stiff. So I needed a safe alternative.

It should be dry and bright but breezy tomorrow. Ideal for painting my woodwork with the water based "Eco" wood protector. Don't blame me if it goes a horrible color! I dreamt that it was turning into Jacobean Oak as I painted it on. Not quite what I wanted!

Yesterday I spotted a folding 'concertina' motorcycle garage while searching for a temporary shelter for my telescope and mounting. Like a fully up-and-over baby's pram or pushchair hood. It occurred to me that the hinged frame could actually be made to rotate on a typical obs. rail and pulleys or wheels.

There's a specialist tarpaulin "tailor" not far away who could probably make one big enough for an observatory. The size is manageable at 3m long x 3m wide x 1.5m high but it would need strong circular hoops to make a windproof structure. Square stainless steel tubing hinged at floor level? It makes one think furiously, about options to a hard dome, doesn't it?

Thursday: I used the fine weather to paint the veranda joists with the Safe-Way 'eco' wood protection treatment. Being made almost entirely of water it went a long way and ran everywhere if applied generously. Being water-transparent made it rather difficult to see where I had already painted. Once surface dry, it turned a thin, highly variable, weak and patchy, bluish-grey. Which made the timber look merely dirty rather than old or weathered. Perhaps it will change again given enough time and weathering?

After an hour in breezy sunshine @ 66F the knots in the timber look darker and more noticeable. The images show the general idea. The darkness seems to depend on porosity and previous exposure. The bottom braces look dark because they have been frequently splashed by rain. The sawn finished posts also look dark because they are absorbent. I noticed the larch floorboards darkened where I had splashed the mixture. Because the liquid was so runny I kept a tub of the mixture inside a bucket for stability. The flat bottom of the bucket sat safely on the braces without fear of toppling or being knocked off by the wind. The bucket also collected most of the drips from the freshly loaded brush.

Click on any image for an enlargement.
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