Time: Several Days on-and-off.
Bravery Level: 5 Star - This Project has a very high scare factor but failure to do something about gel coat damage will ultimately lead to utter distruction of your sailboat...so...forge on me matie, forge on!!!
Contrary to what folks will tell you repairing your Gel Coat is not that hard.
What it mainly takes is patients and a light hand with the sanding.
Let's start with understanding the hull and what can go wrong.
Your hull, generally, consists of 4 layers. There is the central plywood core that is usually coated on each side with fiberglass. The outside fiberglass layer is covered with a material called gel coat.
Many manufacturers will tint the layer of fiberglass beneath the gel coat. This is the case on the Christopher-Jin, so it was easy to tell when I had sanded down to the fiberglass. Unless your have to, try not to go that far. The blue fiberglass is harder to cover back up. But in the case of deep scratches there is not much choise. So get out the elbow grease and forge on!
The main thing with gel coat is to get it as smooth as possible so it looks like the original hull. Some suggest spraying it on. Other suggest placing plastic film or wax paper over the wet gel coat. All are good suggestions.
The Christopher-Jin had an area about 1 sq ft that had orange peeled. The sad part is that it was my fault.
I usually put a rug between the hull and a ladder while working on the boat in dry dock. I have an old bathroom rug that Mrs. Mumphy was tossing that I use for the job. Here's what went wrong. It was fall and I was getting ready to cover the Christopher-Jin for the season. I was in a bit of a hurry as it was getting late and I had a bit of a drive to get home from the cottage. In advertently I left the bathroom run hanging over the side of the hull when I pulled the tarp over the Christopher-Jin and buttoned her down for the winter.
Now as luck would have it, it had rained the night before and the rug was soaked. And as luck would have it the rug was rubber backed. So now we have the deadly combination of moisture trapped beneath a rubber membrane up against the hull for 6 months.
The next spring when I unwrapped the Christopher-Jin I was supprized to see the old rug hanging there. I was further supprized that it was soaking wet. And I was horrified to see the orange peeling beneath when I removed the rug.
After the initial shock, I headed off to West Marine and asked the guys there what to do. Several of them had had experience with gel coat repair and the first thing Vic did was to steer me toward the West System shelf and put a brochure in my hand that was all about Gel Coat.