7.10.2021 [2] More base ring brackets.

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After the cloud thickened too much I went back to fitting the dome's base ring brackets. Eleven completed. Ten more bolts have had their square shanks turned down. I have drilled another twelve brackets with a 10mm bit. Now I can fill in all the spaces I left between the brackets I have already fitted.

I am fitting a 30mm galvanized washer to the upper bolt behind the bracket. This spreads the loads much like the wedge. Thereby avoiding local stresses on the fiberglass when the nuts are tightened down. Slight deformation can eventually lead to star cracking. 

Which is where the rubber washers come into play. They serve a dual purpose. In preventing cracking and simultaneously weatherproofing the bolts.

It was very time consuming to drill the dome and fit the bolts, wedges, washers and nuts. I needed a third pair of hands to hold the bolts in place. While I returned inside to complete the task. So I leaned lengths of 2x4 and 2x8 against the bolt heads after insertion from the outside. Before that they kept pushing back out.

The wedges had to be drilled to fit over the M10x40mm lower bolts. Then the bracket went on temporarily and the nut tightened. Only then was it safe to drill through the dome using the upper bracket hole as a guide.

Then it was back outside to insert the M10x30mm upper bolt. Back inside to remove the bracket. Sweep away the itchy GRP swarf.  Refit the bracket over both bolts. Remembering to fit the large washer. Then fit both nuts and tighten. Then do it all over, again and again. The panorama image below uses MS ICE and five images for 23 brackets and well over 180° coverage. The distortion of the base ring is down to the software. And no, I still haven't tidied up properly. Stop nagging!

I have now completed fitting all the brackets where there are three, full layers of base ring. The rest will have to wait while I decide my next step. 

I am loathe to build out the base ring across the arched doorway. Though I can't fit the drawer slides to the shutters until I do. It would be great to have the shutters easily opening and closing as the weather changes. I am sick of ducking in and out through the low triangles on either side of the closed shutters. 

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