Gobob, if you have concerns about strength and want to add some strength, scrounge up a piece of 1/4" aluminum or 1/2" plexiglas. Cut it to fit under where it will go and butter it up with some good silicone, both surfaces already clean. Predrilling will help also. I've done several over the past metal boats I've had and by making the backing larger than needed I've had no issues. The silicone stops any vibration and you'll never have to replace it if you change your mind.