Depends on how big of a gap you got.
small gaps can be beat with ccf or some deadner.
Non hardning clay could also be used but not forever. After a while the elements(moisture,heat) will break it down.
pics would help too.
Ok cool. When I get my panels off tomorrow I will post some pics. Until then.....The gaps are around 1/2 of each ring and are about 1/2 inch at its largest. I didnt even think to use the deadener. lol damn burnt out noob.