“Spongy” or warped hatch lids can be a big problem for both the safety and function of your boat. (Ross Robertson photo)
July 13, 2023
By Ross Robertson
If you keep a boat long enough chances are that you will have a compartment lid that either feels “spongy” or is visibly warped. This can be a big problem for both safety and function and depending on the severity, it might need to be repaired quickly. Before working on this project boat and prior to receiving the insights below from Capt. Chip Cartwright (owner of Silver Streak Lures ), I never would have believed that this could be a DIY project. Repairing these fiberglass compartment lids is surprisingly easy and doesn’t require extensive experience or many tools.
First, you need to strip hardware and then protect anything left on the boat from getting damaged.
Using a rotary tool or something similar, you want to make a cut just deep enough to penetrate the fiberglass lid roughly a half inch in from the outside side walls. (Ross Robertson photo) Using a rotary tool or something similar, you want to make a cut just deep enough to penetrate the fiberglass lid roughly a half inch in from the outside side walls. Remove this piece as a whole and take care to not damage it. This piece will be reused.
Remove the piece you cut out as a whole; this piece will be reused. (Ross Robertson photo) The internal core is almost always made of foam and can be dug out by a variety of methods. (Ross Robertson photo) Once the lid piece is removed and you can gain access to the core of the lid you need to remove the internal core. This is almost always made of foam and can be dug out with a variety of methods, but Capt. Chip’s prefers a vibrating tool with a wide blade that makes quick work of the removal, and gets under the lip that is left. A little bit of sanding with an orbital tool will quickly remove the remaining foam.
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A little bit of sanding with an orbital sander will quickly remove the remaining foam. (Ross Robertson photo) Next, we dry fit pieces of plywood that are just thick enough to fill the gap tightly. Capt. Chip explained that you want to use many small strips of plywood rather than one or two large pieces, in order to reduce the risk of twisting and warping, and ending up back at square one. This puzzle-like process wasn’t difficult, but it took longer than expected. Mark the pieces before removing them so they can easily be reassembled in the proper location.
Use small pieces of plywood rather than one or two large pieces in order to reduce the risk of twisting and warping. (Ross Robertson photo) After fitting and removing the plywood pieces, they need to be completely coated in a two-part marine epoxy to prevent rot and hold them in place. Use a thickening powder with your epoxy anywhere you have larger gaps. When adding a filler to the epoxy, it becomes more like a paste and less runny, allowing for easier application.
After fitting and removing the plywood pieces, they need to be completely coated in a two-part marine epoxy. (Ross Robertson photo) Use a thickening powder with your epoxy anywhere you have larger gaps, when placing the plywood peices. (Ross Robertson photo) Now it’s time to coat the back of the panel that you first cut out with epoxy and secure it in place. Use clamps, weights, or other household items to ensure a firm bond while the epoxy dries. Just make sure to use a sheet of plastic between the clamp and the lid or it might be there permanently.
Check out the video below to see these steps in greater detail.
VIDEO
In Step 10, we prepare the lids for gelcoat. Coming soon!