Thank you all for your comments. The general thinking seems to be: Butyl Tape good
, silicon and foam tape bad
I talked with Con and Raya as well and have a step-by-step method that I've extracted from their emails just in case this helps others. I'm so glad I found this resource. I own a honda 750 spirit and am a member of another forum. I have to say, it's refreshing to have people be so friendly and accommodating (and not boo you off the stage if you've asked something that's been covered). Simply put, this is a great forum, great advice and great people. Glad to be a member here.
My interpretation from the help Con, Raya and others here:
1) remove windows and then clean all 'silicon' or caulking from trailer and windows with an acrylic scraper
2) clean area with a solvent (white gas/naptha/methyl hydrate or the like)
3) dry fit the window and mask perimeter of trailer next to window with 3m or green/blue painter tape
4) use butyl tape app. the same width of the window flange and stick the tape to the window
5) put window in and attach trim ring on inside
6) tighten trim ring (working as you would when tightening lug nuts in a cross pattern
7) allow butyl tape to ooze out and scrape off excess or allow to spill out on to green/blue tape
8) let sit for a few days as the butyl will continue to 'bleed' - repeat and clean with a solvent.
I've read also that when you take the window out, you can cover the gap between the inside and outside walls (space where insulation would be) with aluminum tape. Should any water get past the butyl tape, it will not go inside the wall, but rather, show up in a more obvious spot. This makes sense to me, but perhaps there is another opinion on this.
When I get to doing it, I'll log my progress in case I can help anyone out.