FWIW, I've been working on repairing some deep gouges in Touche's rub rail from Hurricane Sally last year. The idea was to fill the gouges with some sort of white "stuff" and then wet sand it.
What didn't work: 3M 5200. 100% fail. Not only didn't it sand well, it didn't adhere to the rubber rub rail. Just balled up and rubbed off. What did seem to work: white Flex Paste (not Flex Seal). It actually stuck well to the rub rail and sanded well. Took a lot of elbow grease to wet sand but the final result seems to pass the 10 foot test. It's a LOT of work, however. Initial sand to shape with 220 then progressively finer. https://www.flexsealproducts.com/product/flex-paste/ I also found that lightly wet sanding with 800-1000 grit restores the white rubber. That question has appeared on this list many times. I've never liked any of the suggested chemical or solvent solutions. Not overly happy about wet sanding it either but might actually be less damaging than chemicals. Your experience may vary. -- Dennis C. Touche' 35-1 #83 Mandeville, LA
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
