Kool-O-Matic Replaced
My Kool-O-Matic kitchen fan was still working, but the plastic hood was beginning to show it's age (23 yrs), so I have replaced it with a MaxxAir Maxxfan. Also replaced the bath fan as sometimes it would take some coaxing to get it to run. The bath fan was easy, even the corner screw holes for the base plate lined up. The kitchen not so easy, the old base plate with many screws is much larger than the 14 X 14" roof opening. I didn't take it apart correctly which is to loosen the 3 nuts on the outside of the verticle part of the base plate and just lift off the hood, fan and motor. I drilled out all the pop rivets that fasten the top and bottom parts of the hood together, then removed the fan and motor. The old base plate was well bedded with butyl caulk under the screws and a rubber type of caulk toward the opening. The rubber caulk discolored the gel coat
To patch the screw holes, I used a counter sink and a burr in a drill to enlarge the top of the hole and feather the gel coat. I then filled the holes with an epoxy mixed with a filler but still runny so I could pour it into the holes and fill them. After it hardened, I used the burr again to scuff up the filler and make sure it was below the thickness of the gel coat. I had some unused gel coat that I bought from Extreme about a year ago and tinted to match the off white gel coat on the coach. After mixing with a hardener I put enough liquid gel coat on each hole so that it was higher than the surrounding surface.. I then used a rotary disk to sand it down almost level with the surface. Next I hand sanded (for control) starting with 120 thru 320 until level with the surface; then wet sanding up to 2000 grit at which point it was looking smoother than the rest of the roof. I didn't try to do anything about the discolored gel coat. It's on the roof and impossible to see from the ground.
I splurged on the fans and bought the model with the remote control, but controls are also on the fan. I bought the model with a white cover as that matches my roof. It doesn't let much light in, the dark cover may let more light in as I believe it is clear rather than translucent. Either remote will operate either fan, but as they are infared, no interference in most cases.