Hi Mark Corke here from BoatUS Magazine. Today I'm going to show you how to repair spider cracking in gelcoat. Before I start, don't forget if you find this video useful give us a like below, add a comment, and don't forget to subscribe to our YouTube channel. Before we start doing any repairs, I've got to make sure that the boat's nice and clean. I've already washed it down but my next step is just to give it a good wipe down with some acetone just to remove any remaining contaminants.
So before I do any work to the actual gelcoat itself, I'm going to mask it off so that we don't get splashes and things on the rest of the boat. [UPBEAT MUSIC] Just painting on some gelcoat is rarely effective so what I'm going to do is I'm going to open up the cracks with my Dremel tool and that will give the gelcoat something to bite into and also give us a much better repair. [GRINDING] I've finished the grinding, and if you look carefully you can just see that I've gone down through the gelcoat and barely scraped the laminate underneath. That's because we don't want to make huge gouges we just want a very shallow ones just for the gelcoat to have something to bite into I get a lot of questions about gelcoat and you'll notice that this is Spectrum Color. This is just one manufacturer that makes gelcoat.
They come in loads and loads and loads of different colors. This is obviously Grand Banks white because I'm working on a Grand Banks, but whatever boat you have they can probably match it up to suit. Because this is a huge gallon can of gelcoat, I find the easiest way to decant it is to use a syringe, so I'm going to suck up a syringe full of gelcoat and then I'm going to squirt this into a paper cup. One thing that many people do is they mix up way more gelcoat than they actually need. You'll see how much I've got in here.