Easy do-it-yourself gel coat repairs

Do you have a scratch, crack or soft cover on your powerboat or sailboat? Here’s a quick and easy solution that will save you money. There are many different ways to do the repair, but my method works and isn’t too difficult to master.

Let’s start fixing that crack.

Did your jib pole come loose? Did the anchor rock too hard, or did your sailor friend forget to tell you he had his golf shoes on? Don’t laugh… it happens. He used to make me very angry when he saw the slightest damage to my gel coat and I thought it would never be the same again. You will always see it even after a dose of peppermint. But no one else will, even if the solution isn’t perfect. Motorboats have cracks here and there from pounding as they go through the waves. Sailboats do it the same way, plus all the heeling they do.

I have read all the books and articles and found that they all make a great repair. Some more complicated than others. I took the best of each and now do this procedure for a great solution.

What you will need:

1. Get a short, wide can of Bondo (car or marine body filler) with a plastic lid. This comes with the catalyst you will need.
2. Sandpaper/wet and dry (emery cloth), 1 sheet each: #220, #320, #400, #600
3. Manufacturer Gel Coat Color – It’s worth the wait to get. If not, you can use white gel coat with whatever tints you need to get it right. Most stores have a chart.
You can mix the gel coat during the winter. Get the right color card from Home Depot, and you can play with color through the winter, until you get a match and store it in a jar for spring.
4. Acetone
5. Duct tape
6. Spray bottle, sold at marine or hardware stores.
7. Screwdriver or metal pick
8. Newspaper

As you can see from the bill of materials, it doesn’t have to be a big expense to do your own repair. These materials can last up to 10 repairs. Each time you take care of the crack yourself, you can save yourself hundreds of dollars.

1. To repair a crack, clear the area. Take a good look at it and then take some acetone on a rag and clean in and around the crack. A little goes a long way. Too much is not good. This cleans away wax, dirt and stains so you can now clearly see how far the crack goes and what color to mix as well. The factory gel coat shipped is the original color of the boat’s gel coat. Lightly sanding with 300 grit wet will bring out this color, but it won’t match the rest of the boat. You may need to add a touch of yellow or grey/black to get that washed out colour. Look from the sun If you plan to match the original color, choose the factory color; otherwise, tone it down.

2. Now that the gel coat is ready, let’s go back to the crack. After using some acetone and sanding around and inside the crack, use a flat-hand screwdriver or metal pick to loosen any material in the crack. Make nice thick edges on each side of the crack. Move it around until you get a nice layer of gel with no cracks. Sand the area, blow and acetone again.

3. Put masking tape around the area you are working on, near the crack. Then tape newspaper around it to catch any overspray.

4. If the crack is deep, you should add some bondo. You can use the type that has fiberglass strands. A white fill is preferable. Mix the proper amount of catalyst into the filler and squeeze it into the crack. If the crack is small, use a flat head screwdriver. Keep it only in the crack. Use masking tape along the edges, if necessary. You can keep it level with the surrounding gel coat, because when it dries, you’ll sand it down lightly with 220 or 300 grit and make a slight depression in the plastic. Drying time will vary based on temperature and the amount of catalyst used. Remove excess tape. Use acetone to wash the glue off the duct tape and any impurities.

5. Take the sprayer, read the instructions. For the gel coat (factory or mixed) in the jar. Add some acetone to thin the gel coat so it can be sprayed on. Add the proper amount of catalyst, stir and screw the jar back on and you are ready to go.

6. Find a piece of cardboard to spray on. Feel the force and the amount coming out of the sprayer. Press the nozzle to move it to the right. Release nozzle. Press the nozzle again, move it to the left and so on to get a smooth layer. Now, spray the repair area in the same motion. See how it looks before repeating the process. Don’t try to complete it in one or two takes. Slow and easy. will cover. You can apply additional coats because you will be sanding later. Don’t wear too much. Let it dry. It’s good to do this in 70 to 80 degree weather. If it’s colder, point it with a utility light. It should harden in 15 minutes to an hour, varying depending on the outside temperature. If you want, you can leave it overnight. If it still won’t settle, use the acetone to remove it and try again with a better catalyst combination. You’ll get good at this if you do it multiple times, like riding a bike.

7. After the gel coat hardens, take the lid of the plastic cup and pour some water into it. Tear off a 1″ x 4″ piece of 220 or 300 grit emery cloth. Soak it lightly and also pour some water over the repair. Clean it up. Now, with the folding emery cloth, lightly sand over the repair. Feel the roughness of the area you are sanding. Add more water if it feels pretty flush with the surrounding area. Move to 400 grit, then to 600 grit. Get it nice and moist. Take care not to remove too much gel coat. Check a bit as you sand.

8. The final step is to use some white compound. Add a touch of water. Make up lightly. Thoroughly wash and wax. Are you ready. It is perfect? Maybe, but if not, you won’t see it unless you put a layer of blue gel where the white should go. Meanwhile, you’ll forget where it really is as it fades away. A scratch is basically the same thing, just a large area. Sometimes a light sanding with 300 or 400 grit nice and wet will remove most and sometimes surprisingly all of the scratch without a gel coat repair. It just depends on how deep it is.

With a little practice, you can save yourself a lot of money that you would otherwise spend having your gel coat professionally restored. If doing it yourself isn’t your thing, you may find it helpful to understand the process when you consult with a repair center.