What would you say, then??
All of the complaints I've seen have involved a batch that was sold through irregular channels - forums and
eBay, variously called RAAMmat Extra Gooey and B-Stock. I have no idea what that was and urged people to stay away from it. Could have been asphalt for all I know. I've seen a picture of somebody's hands after working with it and "tar-like" is a good description of that stuff.
I'm only talking about RAAMmat BXT sold through raamaudio.com. I've seen the MSDS for that and it doesn't contain asphalt - although Rick has inexplicably stated that he wished he could get them to put a small amount of asphalt into it, which makes no sense to me at all. Regular RAAMmat BXT is stickier than the higher priced and higher quality alternatives, but it doesn't smear on your hands. THe adhesive is rubbery, but not as elastic as the others.
It's my understanding that the sub standard RAAMmat will never be sold again, so let's stick to RAAMmat BXT. I am not saying it is a less expensive version of V-Max or Damplifier, it is clearly different and not as good. I'm saying it is the least expensive product that can be relied upon. The others will perform better. I'm only objecting to the use of the word "tar" because that means asphalt and there is a big difference between asphalt and RAAMmat.
It really isn't a question of there being a component in butyl rubber that explains any of this. There are many grades of "butyl" and none of these products are pure butyl. Each has significant quantities of additives. Some add mass, some promote adhesion - many different things go into the pot. Once you've used the higher quality materials, it would be hard to go back, but some people can't justify the extra cost. Anybody who is considering using FatMat, Peel & Seal, B-Quite Extreme, Sound Destroyer, R-Blox - any of the asphalt being sold as sound deadener - is going to be much better off using RAAMmat.