Long-term Clear Vinyl Protection

When the clear vinyl on one of our multihull test boats began to crack and fade after approximately 10 years, the costs estimates for window replacement began at around $1,500. Thus began our investigation into ways to prolong the life of clear plastics. In previous issues weve reported findings at the six-month and two-year marks. Here, we present a last look at products and best practices to preserve clear plastics, and the five-year performance of four popular types of clear plastic in the marine environment.

Used Nylon Three-Strand Rope Faces The Ultimate Endurance Test

The nylon three-strand dock lines used for this test had weathered significantly, and chafed noticeably where the lines exited chocks and made contact with cleats. We put these lines under increasing tension in laboratory conditions and tested them to destruction. Our test shows that even when the effects of chafe were eliminated, up to 75-percent of the original tensile strength in our sample ropes was lost. These findings fly in the face of the conventional rhetoric that views nylon as such a strong material that one should always opt for thinner line due to its better elastic effect. To the contrary, within reason, this overly springy, rubberband-like function is a foe rather than a friend. We left the lab realizing the importance of taking a close look at dock lines and other nylon-line applications, noting the last time they had been replaced and why tropical storms and noreasters take such a heavy toll. A new set of dock lines is cheap insurance, and money well spent.

PS Advisor 01/15/99

Adding a StaysailCan you advise where I can find basic design parameters for adding an inner forestay to my 40-footer? Jim FitzgeraldHollywood, FloridaAdding an...

Caring For Your Marine Diesel Engine

Expecting calms for most of the passage, we set out in a flat calm with 70 gallons of fuel. Six hours later, around mid-day, the engine wailed, screeched, clanged, and died. Hardly a ripple stirred the Gulf of Panama.