9.11.2021 Slit rib, fixing brackets.

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Tuesday 9th 48F, overcast and breezy.

The first exercise was to bend the new brackets to match the dome's inside radius. I put one leg in the vice and hit the free end with a rubber hammer. By sheer luck this provided the ideal shape without further ado. 

The next step was to mark the inside of the dome at 20cm intervals. Followed by setting the distance of each 10mm hole, from the rib. I used one of the previously drilled and bent brackets as a pattern.

Now I could pilot drill the dome from the inside. Where I had just made the marks with a permanent marker.

After which I went outside to open up the pilot holes to 10mm. Ready for the bracket fixing bolts. This avoided my standing under a shower of fiberglass dust. Had I worked from the inside with the drill overhead.

A rubber washer was slipped over each bolt and these were then inserted into the drilled holes from the outside of the dome.

Then back inside the dome. To offer up each bracket to the projecting bolt threads. Slip the nut on loosely and move on to the next. Tightening the nuts at this stage would be premature. Since the brackets could not be guaranteed to lie flat on the rib.

I drove four 5x25mm screws through each bracket into the slit ribs. There are three empty holes remaining, per bracket, but these are very inaccessible to the bulky drill/driver.

Finally, I could tighten the nuts. To flatten the rubber washers under the heads of the bolts as gaskets. While simultaneously pulling the bracket up tight against the inside of the dome. I briefly considered adding large, stainless steel washers under the nuts. Though the brackets are probably stiff enough on their own.

The images show the results. 10 brackets fixed per slit rib. Already hidden away in the darkness of the completed dome. They can be painted matt black [or matching green?] for even greater invisibility.

 

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