SUP/Surfboard Crack and Ding Repair

Have a crack or ding in your surfboards or SUP? Fear not, this kind of damage is easy to repair. With a couple hours of work you will be in the water in no time at all. You do have the option of taking it to a shop, but where I live at, I’m far from the ocean and don't even know where I would take a board to be fixed. So it was just easier to do it myself.

The first thing you need to do is inspect the crack or ding. Make sure you look for any hairline cracks that may be hard to see. If you neglect to repair the entire damaged area it could spread and cause a bigger headache than if you just looked it over really good. I used a Sharpie to “highlight” where all the tiny cracks were so they were easier to see.

Next, you need to remove all of the damage. In my case it was a crack along the rail of the board. For this I took a Dremel tool and ground a V into the material to grind out the crack. A V groove will give a larger surface area for the woven fiberglass to adhere to when you lay it on. If you simply grind a channel into the board with a vertical face you will have a hard time laying fiberglass in and having it “stick”. It will also not be as strong as the V groove repair.

Once you have your crack or damaged material all ground out you may need to make a backer before you lay fiberglass. The SUP I was working on had a foam core and I ground into it a little. To correct that, I poured some resin into the base of the V groove. If I would not have done that, the fiberglass would have a hard time filling the rough gap in the foam.

With the backing in place and nearly cured go ahead and lay your fiberglass. I chose to saturate the fiberglass before I put it on. This works very well for small crack or punctures in the board. If you are working on a larger area that has severe damage or a larger area in general, it will be easier to put in on dry and press the resin through the fiberglass. Either way, make sure the fiberglass is laying all the way down in the V groove. As you add layers make sure you are pushing out all of the air bubbles. If not when you get to sanding you will wind up with pockets that need to be filled in. Add as many layers as it takes to build up the V groove above the original surface. You don't want any low spots.

You can start to sand the fiberglass as soon as it tacks and has a firm feel. It might gum up your sandpaper faster but it will be easier to sand. I let the fiberglass cure entirely and used an angle grinder with a 120 grit flap wheel to take off the high spots. BE CAREFUL! If you go crazy with the grinder you could take off too much material and have to glass it again. Once the high spots are taken off start profiling the fiberglass to get it back to its original shape. Once you have a rough profile, start working with finer and finer grade sandpaper. You are looking to sand out the rough scratches from the previous grit sandpaper. Once they are out move up to a finer grit. I would recommend at least going to 400 grit before paint. 600 Grit is most likely the best and anything over that is just a waste of time.

Once you have it profiled and sanded smooth you need to get ready for paint. I DO NOT RECOMMEND to clean the boards with any type of solvent it can get into the surrounding resin and cause havoc when you go to paint (Trust Me I Know!) Blow off the dirt with an air hose and wipe it down with a really clean rag. (microfiber ones work the best). At this point this is the last step before paint, so recheck your sanding job and make sure you got all the scratches out and there are no other problems with your work. This is the last chance you get before you cover everything up with paint.

Now to prep for paint. Tape off any areas that you don't want paint to reach. For me this was the purple foam decking. That's all I taped off. If you want to tape off your entire section you will wind up with a paint edge when you peel the tape off which will need to be sanded with 400+ sandpaper. Try to not use tape or only it vital areas. The rest will get feathered as you spray the paint. I used Rust-Oleum's gloss white. It had good coverage and matched really nice. Allow your paint to cure fully.

The last step it the hot coat, it’s the exact same resin you used for the fiberglass. All your looking to do it give everything that you painted a thin layer. Think of this last step as a shell to protect all the work you did to your board. Make it as thin as possible to blend into the existing board surface yet thick enough to have good coverage over your work area. (no skippers!)

Allow your hot coat to fully cure and you're done. Head out and enjoy the water