Drilling holes in Gelcoat:

Gelcoat is a thin, brittle coating, not unlike an eggshell. If you simply attempt to drill a hole into the fiberglass, you will have extreme difficulty in drilling holes without cracking the Gelcoat. The method I use, which works about 99.9% of the time is to put the drill in reverse, drill through the Gelcoat, then put the drill in forward and drill through the rest of the laminate. The Gelcoat is only about 1/16" thick, so drilling in reverse won't take long. I am not quite sure why this works so well, but probably has to do with taking less "bite" out of the material.

Another consideration to keep from cracking the Gelcoat is if you are going to screw into the fiberglass, then use a countersink or larger drill bit to counterbore the Gelcoat (but not the underlying fiberglass) to a larger diamater (again in reverse) to keep the screw threads from coming into contact with the Gelcoat (as they will surely crack the Gelcoat).

Some boaters like to cover the drill area with Blue Painter's Tape before drilling, but I have not found this to be effective in preventing cracking of the Gelcoat. If you have never tried the reverse drilling technique, you will be surprised in how well it works. However, Blue Tape is great for marking off the holes.

For more information on drilling holes, visit: Drilling holes in a fiberglass boat in the Concepts and Tutorials section.

Did you know that?

When powering devices via DC, there is a significant problem concerning voltage drop along the wire. The DC voltage drop can be so severe that it must be accounted for anytime you power high-current devices. This disadvantage is the primary reason that your homes are AC powered - because there is no similar voltage drop when using AC power.

I suspect that some of you may have experienced voltage related issues after you wired in a new stereo unit or other device that takes significant current. Perhaps you wired an external amplifier to the existing wiring at the helm, and now, nothing works right. Many boats are just not wired to handle high current loads.

The universally accepted rule-of-thumb, as well as recommendation by various boating industry groups, is that for sensitive electronic devices, you should not have more than a 3% loss of voltage due to voltage drop along the wire.

Say for ease of discussion - your battery is producing 12VDC - then a 3% voltage drop means that the voltage found at the electronic device should never be less than 11.64V. Just where does the 3% loss in voltage go? It is dissipated along the wiring itself, and is a function of wire size, current flow, and distance. What is needed is heavier wire to carry the increased current demands of the new electronics you installed.

For more information on properly sizing wire to minimize voltage drop, visit: High Power DC Wiring in the Concepts and Tutorials section.

New pages:

A new section was added for Boating Recipes, found under the Reference section. How is this boat-project related do you say? Isn't preparing dinner a project? I think it is, besides it provides the lighter side to boat-projects, as every project doesn't require a drill. My goal for these recipes are those that are boat-friendly. For example, when preparing food on a boat, you are limited by the heat sources; usually a microwave or stove, cold-food storage (small refrigerator), and you won't want to have to dispose a lot of garbage or grease. Nor do you want to plaster bacon grease all over the headliner in your cabin. So the recipes all take these factors into consideration. I only have one recipe currently, but its my favorite chili.

I have also let out one of my secrets to drilling holes that are perfectly aligned. You know, one thing that makes a project destined for the boat vs. the dumpster is something as simple as asthetics. No one wants to install a ugly-looking project in their boat. And one of the defining factors is whether or not you can drill holes in a straight line. I created two pages for this topic; one page on Drilling Holes in Alignment in the Concepts and Tutorials Section, and one page on Building a Precision Drill Press Table in the Misc Section to allow you to drill those holes.

Thanks;

Al