I am finally at the point of installing the duct from the bathroom exhaust fan to the 4" rigid (split seam) duct.I used a
4"aluminum flexable duct. Had to fight to get it on the rigid side a bit small ( sliding it on over the female end of duct. Then on the fan side it was too large. In both cases as I tightened it it bulged out (seem to leave like a bulge at the clamp). Is this normal? Should I be using some sort of adapter?The rigid is 4" and the port out of the fan is 4". I just don't understand. Is this aluminum flex just bad in this way. I saw some aluminum flex with ends on it, and the flex with the insulation on it, and the alluminum foil looking stuff at HD, Should I just clamp down on the alluminum and duct tape around the inperfections or budges. What am I missing here? What works best. I would had went rigid all the way except the output from the fan looks like it would like a hose. Any help would be appreciated.