Shortstripper
Firstly I dont have anything against gliders and stress I brought this up as a discussion point only.
You brought up a sensible point which is that gliders while flying in IMC should be in contact with the ATC unit that would be used by the majority flying IMC in that area. They can then listen out for positions of IMC aircraft and make regular position and level block reports.
Using glider frequencies is not going to help us as its likely we will be busy on the ATC unit covering that area and cannot be locked onto a glider frequency. Communication is vital for seperation but we must all be communicating. Maybe a rule stating that all gliders operating at 4000 feet and above should change from the glider frequency might help.
Picas above 4000 feet would also be of use. Other than flying under CAS its not hard for powered IMC aircraft to fly above 4000 and cruise above the majority of gliders. In my case i was coming down from FL100 but even in this case I held 6000 feet till clear of the gliding site. At some point even we have to come down but shoul know of other aircraft in IMC in that descent.
Pace