Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
The boat came with two large 4 holes in the cockpit bulkhead, originally containing a depth sounder and a knot meter. The PO had replaced the knot meter for a speaker, after the knot meter had failed.
I wanted to install 2 new MFDs, but of course, the holes are 1/2 to big. So this is how I reduced the size of the holes to fit the new instruments.
First, I use some fiberglass matting and epoxy to create a fiberglass board approximately 1/4 thick. Then, I use two hole saws to cut out 2 rings, the outer dimension to fit the existing holes, the inner dimension, the desired new size.
I epoxied the two rings inside the existing holes. The cabin side ring, flush with the bulkhead, the cockpit side ring, just about 1/8 inside, leaving a lip.
Now I filled in between the rings with thicken epoxy over several applications, building up the gap. After curing, I used some Marine Tex to fill in the 1/8 lip on the cockpit side. Next, I used the smaller hole saw to clean out the hole, and wet sanded the Marine Tex flush with the surface of the cockpit bulkhead. The color of the Marine Tex is close to the color of the original gelcoat.
And finally, I mounted the new instruments.
Why Marine Tex and the 1/8 lip? You cant use gelcoat over epoxy. (but you can use epoxy over gelcoat). And epoxy breaks down exposed to UV, so it needs to be protected. Marine Tex is epoxy based with UV protection. However, it will yellow over time. (Actually good for me, closer to the original gelcoat color) Not a perfect fix, but fine for this application.
B&G Triton Digital Display. (old style). I had them sitting around for a year now, finally had time to install. The original Triton display is no longer available, as they have been replaced with the Triton2, at +$150 more.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.