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Hi All,
I have to agree with Jay & Frank,
I will be using Sika-flex as advised by Greg who made the window. Even
though my ports are VERY heavy there is no way to have absolutely no distortion
from welding.
Using Sika-flex as a setting bed will mitigate this problem. I plan on
placing a very heavy bead in the base corner of the seat and pulling the window
into place with a retaining ring. The excess will be squeezed out and is messy,
but I plan on having my sign guy make some adhesive backed masking to cover only
the portion of the port that is not covered by the seat.
Then I can wipe away most excess, then remove the masking. This will not
risk scratching or cutting the window acrylic.
Best Regards,
Jim K
----- Original Message -----
Sent: Saturday, August 30, 2008 10:27
AM
Subject: Re: [PSUBS-MAILIST] O-Rings
& Acrylic Ports
Hi Jay. That makes a lot of sense. If you have an "O" ring, the seal is
only at that small point where the rubber contacts the plexi. With a bed of
sealant, the water has to get past the sealer between the outer support ring,
and then through the back flange as well. In my case, that's 5 inches of
sikaflex versus about 1/8 inch for an "O" ring. The down side of course is
that there's no way you're going to save that window if you need to remove it.
I have a method in mind when I mount the plexi. I plan on
rolling the sub so the window is on top, put in some small spacers to set the
plexi at just the right depth. Tape off the frame to the plexi so there's no
places where the sikaflex can dribble out the bottom. Next, I'll make
some nozzles from sheet metal that fit just inside the space between the
steel frame and plexi. Again, seal that connection so nothing dribbles out.
Using a pump, I'll inject the sikflex into the space from the bottom and all
the air will be pushed out the top. I've used this method before when I was
making gaskets on some high pressure pumps that were too difficult to
remove from their locations, and it worked quite well. As far as I know, the
pumps are still in service and it's been over 10 years.
The sikaflex came in 5 gallon buckets. The biggest pain was cleaning the
pump between applications. We used solvents, but ultimately had to
dis-assemble the pump and hand scrape the whole thing after we were done.
Frank D.
It's only a deal if it's where you want to go. Find your travel deal here.
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