Boat Project, Bimini Windows

We usually don't post details of boat projects here since many of you aren't boat owners and likely aren't interested in the minutia of this sort of thing. I'm making an exception as this is a bit of an experiment and may be of special interest to boat owners.

The issue is fast fading windows in the top of the bimini used to see the trim of the main sail. This plastic window material totally hazed up in 2 years. Not good since our bimini configuration would require a whole day of dis-assembly, then repair and then another day to reassemble.

 You can see a patch where we tried to clean but you could still not see through.

Totally hazed over by UV

My plan was to replace the thin vinyl with acrylic sheet. The acrylic is much more UV resistant and can be polished. I found a local plastic fab shop that cut the sheets to my specs and polished the edges. I then measured for hole placement several times and drilled clearance holes for #10 machine screws with a dill bit specially made for drilling plastic. Lubricating the drilling with a water and baking soda mix also helped prevent cracking the plastic.We carry a piece of plywood to serve as a portable workspace. 

 My open air workshop

Carefully drilling at very low speed so I don't have to take another 5 mile bike ride back to the plastic shop for replacements.

After drilling all the holes in the windows, I marked their location on the blue Sunbrella canvas top and "drilled" holes in the Sunbrella with a soldering gun. The gun burned through the several layers of Sunbrella and sealed the edges of the holes to prevent unraveling. Then, with help from Chris, I marked a set of 1" acrylic strips I also had made by the plastic fab shop to use as a clamp on the underside of the Sunbrella. Back to the 'workshop' to drill the clearance holes in the strips of acrylic.

We dry fit it all together to make sure everything lined up, which it did quite well. The last step before final assembly was applying "Bed It" butyl tape all around the perimeter to seal out water. Bed It butyl tape is excellent for this. Here are the results:

 A bit industrial looking, but works very well

You can see the grey Bed It butyl tape smushed between the acrylic and the Sunbrella

And a significantly improved view up at the boom. Main sail trim will be much easier now.

I might have preferred 1" aluminum or polished stainless steel strips on the inside. We'll see how this performs and perhaps make an upgrade at some point.  We have Sunbrella covers that will be velcroed to the inside, awaiting more adhesive backed velcro for that finishing touch.

Now we need to get out sailing!