BOAT TECH THE
BY DON CASEY AND OUR BOATU.S. TECH EDITORS
WRITTEN BY THE TOP TECHNICAL WRITERS in the country, BoatU.S.’s vast archive of technical stories con- stitutes one of the most invaluable and popular pages on our website. Our trusted tech team of experts fills
Boat TECH with in-depth advice for members on how to do everything
on your boat from plumbing to polish. This month, we’re unveiling
our all-new presentation of the site. We’ve made it easier to use, and
enriched it with more useful photos and advice than ever before.
Here’s just a sampling.
GELCOAT SCRATCH REPAIR
Surface scratches can be buffed out of gelcoat with polishing compound, but deep scratches
must be filled. When the gelcoat surrounding a scratch is in good condition, the filler of
choice is gelcoat paste, which provides both filler and finish in a single application – but not
in a single step. The surface of the cured paste will be uneven, so sanding and polishing are
required to smooth the repair and blend it with the rest of the hull. Except for color matching, gelcoat repairs are easy and straightforward.
Never try to repair a scratch by simply painting over it with gelcoat. Gelcoat resin is too
thin to fill a scratch and gelcoat paste too thick. Instead of penetrating scratches, gelcoat paste
will bridge them, leaving a void in the repair.
To get a permanent repair, draw the corner of
a scraper or screwdriver down the scratch to
open it into a wide V.
Work the gelcoat paste into the scratch
with a flexible plastic spreader. Let the putty
bulge a little behind the spreader; polyester
resin shrinks slightly as it cures, and you’ll
sand the patch, anyway. Don’t let it bulge too
much or you’ll make extra work for yourself.
Scope is often defined as the ratio of the
length of deployed anchor rode to the depth
of the water. That is so wrong! Scope calculations must be based on the vertical distance,
not from the sea bottom to the surface of
the water, but from the sea bottom to the
bow chock or roller where the anchor rode
comes aboard. For example, if you let out
30 feet of anchor rode in 6 feet of water,
you may think you have the appropriate 5: 1
scope, but if your bow roller is 4 feet above
the waterline, your scope is actually only
3: 1. Scope is required to make the pull on
the anchor horizontal; the more upward pull
on the anchor, the more likely it is to break
out. Minimum scope for secure anchoring