glazing tape and continuous rubber seal question

hey folks, rod recommends butyl tape. but somehow it's hard to find here. i asked a couple of glaziers but they all say that they don't have and use it. so i wonder if anyone of you have experience with stuff from Tremco-Illbruck? (illmod 600 e.g.) it's a precompressed open cell polyurethan stuff. they say it's for soundproofing applications. i could get it for a good price 10,-€/10m (at least i think it's a good price...don't know how much butyl tape would cost.) and another question: rod also said he uses water & ice seal for the window cavity (-> look here) and he also says there (this is a quote): "...the rubber is just a seal to stop the free flow of air through the space - and thus keep dust from the inside of the wall cavity from working it's way into the window." meaning to me that i could use any kind of foil or tarp e.g. as long as it ain't 'hard stuff'. is that right? thanks and greetings, carsten

Carsten, the product looks fine- not a butyl - but not bad - remember - in the end everything is about stopping the passage of air - and there are actually quite a few ways to skin that particular cat........ As far as the center opening goes - either of your idea will work......... Rod

grrrrrreat! good news. i think slowly - very slowly - i'm getting it. thank you, carsten