TOPIC: Sanding Gel Coat Oxidation

My '73 Chaparral is a fantastic shade of wayback brown but it's got pretty heavy oxidation and white frosting on the old gelcoat. This weekend I was tinkering around in the shop when picked up an extra fine foam sanding block, and just on a whim I used it lightly on one of the bad areas on the boat. The chalkiness buffed right off.

Which, of course meant I spent the rest of my free time in the weekend wet sanding all the 'glass above the rub rail back to a rich, chocolate-pudding brown.

In some of these you can see the before and after

Where I started:


...and then I worked my way around the bow:



And after a couple coats of liquid wax it looks pretty spiffy:







You can see in the last shot I started on the interior gunnels too, which were almost as bad as the exterior. I ran out of muscle, will power, and sanding sponges Sunday afternoon. I'll pick up a few more this week and work on the rest of the interior next weekend.

The long range plan is to do the hull below the rub rail with my DA sander this winter, and eventually use the DA to buff everything to a decent finish. Right now it's kind of a semi-gloss finish, but with wax it's shiny and the wax will protect the surface until I get a chance to finish it out correctly. When I get to buffing I'll pull all the deck hardware but I don't think I'll fix every little ding and scratch. That patina was hard earned over 40+ years of service and it seems a shame to erase it all.

We gotta be running on the same wave length with the brown tri hulls!
Same chalky brown 70's top side but I did a different approach over the weekend. The sparkle color was not just chalky in spots but felt "sandy" so I didn't really want to do any heavy buffing for fear of working into the sparkle flake so I tried something else. I had a part bottle of Turtle Wax trim restorer, the stuff that is used on automobile outside plastic trim. I worked it onto the surface and of course it seemed to bring the shine back but it had a greasy feel. Let it sit for a day and then wiped it down with a dry rag, put on a really heavy coat of regular liquid car wax and let that sit a few hours until it dried then polished that off. It doesn't have the high gloss lacquered shine of the newer models but a soft gloss that I'm happy with. Haven't touched the hull yet but like you I think a foam power buffer with some mild polish will bring it back to looking good. Didn't take any "before" pictures.

nice. I kind of prefer the soft gloss too. It seems easier on the eyes out on the water but I also think it's more likely to be damaged by UV and chalk faster. The surface has a microtexture that leads to more absorption of the UV rays and (obviously) less reflection. I think keeping it waxed and or covered will be important, but the boat obviously stays inside so that's not a problem.

I've used the trim restorer on black trim before, but it only lasts a couple weeks. be interesting to see if it does better on the 'glass.