Re: Hull issue..be worried??
M R Thanks
A bit more info to understand the situation.
Typically when you apply a coating to a surface it has different properties than the substrate it’s protecting, paint over wood, metal, plasterboard, or even over epoxy to protect it from UV light. With resin and gel coat, they are both made of basically the same ingredients, resin just lacks the pigments to protect it from UV(no they aren't exactly the same), so the properties and characteristics are similar. This means water can have about the same effect on both of them, there are different grades of each, but they still have many things in common. So gel coat isn’t really that much of a barrier when it comes to water, it will take longer for the water to reach the laminate, but it eventually will with or without gel coat, and the laminate will need to fend off the damage from water the best it can. Frequently you find the point of failure starts on a strand of glass or possibly a void and grows from there into a blister. This rarely happens on trailered boats, but if the wrong methods or products are used it may happen on moored boats. If the boat is on a trailer except when used then it isn’t in the water long enough to create problems even around the chipped gel coat, if it’s in the water all the time, and the hull is susceptible to blisters, then it will eventually blister on every portion under the waterline whether there is a chip or not.
Now if you had a hull that either had blistered and then been fixed, or was susceptible to blisters, and it had several coats of epoxy applied to it as a barrier from the water, then yes a chip could be a more serious failure point. This is where the protective coating (epoxy) has different properties than the substrate (polyester laminate), epoxy has much better water resistance and if the coating is thick enough it will protect the laminate from either re-blistering, or blistering in the first place. Now the epoxy needs to be protected from UV light so it’s painted, the paint may not be a good water barrier, but that work is done by the epoxy, the paint just needs to protect the epoxy. Again the substrate (epoxy) has different properties than the coating protecting it.