I don't use the VHB at all. The Quilosa has great initial bond, and is only workable for a few mins. I use lots of it, put the window in place, brace if needed to hold there (if its got lots of bend, for example), then use a scraper and then thinners to clean up the ooze. Small bits of timber - or matchsticks - can be inserted until the initial bond is taken, to ensure sealant thickness, then removed and the holes filled - make certain that there is lots of matchstick sticking out for removal!