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.
SV Laurie Anne
1988 Brewer 40 Pilothouse