When I implemented and described my first idea to solve the problem of rain getting into my dome, various people expressed some doubt as to whether or not it was going to work, and I too had misgivings. So I thought of a better way to do it which I illustrate below.
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The idea is to fix a draught excluder along the outer edge of the shutter. I could not get a good picture of the fitting before I put it in place, so here it is illustrated diagrammatically. The draught excluder is the brush type designed to screw to the bottom of a door to block draughts coming under it. This is shown in the diagram in white with a black brush. It is fixed to a strip of poster hanger (shown in red but actually white) by 3 mm nylon bolts (shown in dark blue) and fixed with the head inside the poster hanger. It is necessary to cut away part of the underside of the poster hanger to avoid the attachment for the chord that closes the shutter. (But note that this attachment is not in the centre of the shutter.)* I chose the 25 mm version of the draught-exluder (they are also available in 15 mm) to ensure that the brush is well bent over by the dome. The curved bristles will deflect the wind over the dome and they will remain in contact with the dome even if the shutter should lift in the wind (it certainly rattles). The bristles may fold under when the shutter is opened, but will return to the correct orientation when the shutter is closed. *(I actually used the two pieces of poster hanger that came from my first solution. This leaves a gap at the centre through which water may drain, but it will drip onto the top of the dome and drain down against the brush. The main purpose is to deflect the wind over the dome and prevent it blowing water into the dome. One continuous piece would be a better implementation.) |
Finally, three pictures showing the unit in place. The first two are general views from two different perspectives. It is difficult to see how much the brush bends against the dome. The third picture shows this better in a close-up of one end. In all the pictures the white draught excluder tends to merge with the white dome. The third picture shows some damage to the corner of the shutter; I don't know how that could have happened. Fortunately it is made of fibre glass.
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