David, Look here for a good explanation of process. _Repairing machined holes in fiberglass - West System_ (http://www.westsystem.com/ss/repairing-machined-holes-in-fiberglass/) www.westsystem.com › ... › Boat Repair › Fiberglass Boat Repair and Restoration (https://www.google.com/#) When repairing fiberglass boats, the challenge is to determine an ... A hole with a large diameter is more highly stressed in a thin laminate than in a thick ... GO In a message dated 8/28/2016 11:58:36 A.M. US Mountain Standard Time, dajada@gmail.com writes: Question for you all… The previous owners of my M15 mounted a depth / fish finder on the wall between the cockpit and cabin. See attached photo. Unfortunately, this ruins the most comfortable spot to hang out in the cockpit! I’d like to relocate the depth/fish finder to a board that will fit into the bottom slat of the hatch boards when under way. My question is what’ s best method for filling the 3 small holes that will be left in the fiberglass? The screws are probably #8 or #10. I’m thinking of using thickened epoxy from the inside, then a tad of gel coat touch up on the outside. If that sounds right, the second question would be if there’s any tricks to matching this color of gel coat. I’ve done a fair amount of fiberglass and gel coat repair on kayaks and assume it’s the same, but I want to make sure I’ m using best practices here. Thanks! David D. dajada@gmail.com M-15 #219 “Sequel”