12.10.2021 [2] Shutter top board fixing.

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It has just occurred to me that I do not need to remove the second shutter. I can remove just the top board and copy the other shutter's drawer slide position. All it needs is to remove the few screws securing the hole plate at the outer corner.  Then fix the drawer slide to the board before replacing it in the shutter.

I had planned to upgrade the hole plates with some serious, roofing angle brackets. Though I still haven't found anything suitable yet.  

I am still rather blank on the inner top brackets. I need to attach solidly to the outer side of the shutter rib. Turn it into a stiff, flat, horizontal section, to pass over the zenith board. Then turn a right angle to fix onto the inner face of the shutter board.

This looks like a modification of a length of slotted, steel angle iron might work. Though I ought to heat the [face] bend to red hot to ease making the right angle. I can see it in my mind but it needs refining. Perhaps I should think in terms of bolting something together? An angle bracket needs extra depth plus bolt heads.

 

If I carried the bolts through the GRP shutter cover then I'd get a really strong fixing. I'll have to think more about this. At least I am finally seeing a possible solution. My hopes for an off-the-shelf, roofing bracket has not been fulfilled so far. 

Whoops! I have been worrying foolishly  about clearance across the entire top of the zenith board. The only clearance needed is when the shutters are fully closed. The whole lot moves well away from the zenith board as soon as the shutters open. It's all a matter of building a full, 3D, moving picture in my head. It is finally beginning to form. I was too fixated on a commercial roofing bracket.

I could even treat the fiberglass cover as a structural unit. Plate over the top [or inside?] where it matters. To retain the required, local stiffness. 

Both top, drawer slides are now fitted to the shutters and zenith board. As can be seen by the images above.

13.00 Lunch.

Afternoon. I fitted two sturdy bars of scrap aluminium on top of the shutters.  A crude, but simple, solution. The bars were clamped in place by the top bracket bolt. The stiffness of the bars straightened out the GRP covers quite nicely. Where they were sagging slightly under their own weight. A dreadful picture taken at dusk.

I may be able to find some brass, furniture assembly dowels [barrel nuts.] These will allow me to tension the bars onto the shutter boards. Sandwiching the GRP at the same time. Without risking splitting the plywood boards with wood screws into the end grain. 

The usual steel barrel nuts will rust very quickly out of doors. Brass barrel nuts are made in China but not shown in Danish searches. I shall just have to make my own and use stainless steel bolts. A spot of grease will help to avoid sticking. 

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