trick on sealing acrylic that has to slide into a frame....

[stantale]

Ok so I've read all the posts about what to do and not with rebeddubg port lights. I am going to use butyl tape given the size of the windows and expansion.

I have two long 4' port light from a 1970 rawson that I am rebedding. The frame is aluminum and made of 2 parts. A piece that holds the window, and then a piece that goes on the outside to sandwich it to the deck. They're all in good condition and I can seal them nicely to the deck. All the screws are "in" the whole with a flange and don't go through the deck so it's a nice design.

But.... the frame piece that actually holds the window is made of two parts, kind of line two squat U's that go on both sides of the window and then connects with a set of screws on the short side. Hard to describe...

In any case the gist is this: when I slide the window along the short edge of the frame in the U, how do I keep all the butyl tape I put in the guide from sliding around and making a bad seal?

Can I coat it with something slippery that will go away on it's own? presumably oil's a bad idea ;-) Some soapy solution? I'm afraid to put anything at all in there given that clean enough isn't clean enough, to quote the master.

Any tricks of the trade? I can bend out the frame a little which might help but not too much for obvious reasons and near the corner it will be a problem anyways.

btw, the gap in there is quite large, there was a foamy like rubber gasket that was at least 1/4 in in there before.

sorry for the long post.....

stantale

[Minnewaska]

OOophfff. After a bottle of wine and couple of scotches with dinner, I have no idea what you are trying to describe. Pictures may sober me up, if you have them.

[stantale]

yeah I figured. will try to take pictures...

Ok how about this:

I want to coat my foot with a sealant, and then put it into my shoe without all of it getting scraped off around the ankle. Looking for some form of lubricant so I can get my foot in there more easily.

Except my foot is acrylic, and my shoe is aluminum.

As you can tell, I've had some scotch too.... it's Friday after all...
.

[Faster]

Are the seams of the 'squat "U"s' middle top and center, or fore and aft ends? btw I'd use Dow Corning 795 for that step rather than butyl.

Assuming I'm picturing this correctly:

I would mark the edges of the frames on the port lens, and mask both sides of the new lens to that line (or cut the protective paper to that line) leaving only the edges exposed. If the gaps in the frame are fore and aft the 'sliding displacement' should be minimal. Now mask the outer edges of the frames (ie "U"s) and generously goop the grooves . Then slide all the pieces together, and use a soapy gloved finger ( ) to tool the sealant all the way around the joints, wiping up the excess.

I'm assuming that you'll need to 'seal' this assembly into the sandwiching frame halves too... use a similar technique. Spending an hour or more masking will pay off in cleanup time and resulting appearance. Butyl may work there too, though.

Of course, could be I'm completely off base.....

[jrd22]

I think you are right on Ron. I "think" I know what type of frames the OP is talking about, very similar to ones that we had in the Northsea. If you can assemble the acrylic in the frames and there is a little slop I think you could inject the DC 795 in from both sides to seal it. The foam took up a bit of room as I recall and with that gone hopefully you can use the 795 after assembly. There is no lube that I know of that will allow you to slide the acrylic past the butyl without pulling it, water would be my only guess but I wouldn't count on it working perfectly.

[merc2dogs]

I did similar frames a short while ago and what worked best for me was to squeeze the ends of the frames for a tighter fit on the glass, fill the bottom of the channel with sealer, then lay them down on a sheet of plywood and put small hooks in the open end, then use string tied to eyes screwed into the ply to pull them open wide enough for the glass to slide in without dragging the sealer.