Splash Out on Spray Rails Page 2
Placing the rails takes a bit of artistry. The instructions say, “The perfect solution is to study the effect of waves striking the bow in all sea and speed conditions to determine the optimum location of the rail.” Based on his recollection of where the spray came over the gunwale, Thiel decided to start the rails about two feet aft of the stem and about a foot above the waterline. We taped the forward end of the port rail in place with masking tape, then worked the rest into a fair and graceful curve. Once the port side looked right, we measured up from the waterline every foot or so, transferred the measurements to the starboard side, and taped that rail in place. Before removing the rails, we outlined their positions in pencil to provide guidelines for final installation.
The M-1000 rails come with two bonding strips already attached, on the top and bottom of the mounting surface. During shipping the strips are protected by slip-on plastic guards; there’s also a peel-off film that’s removed just prior to installation. But first the gelcoat under the bonding strips has to be coated with 3M-94 primer, packaged in four crushable ampoules. Squeezing and shaking an ampoule, then sliding its cotton-like fiber end along the hull applies the primer. One ampoule primes one bonding strip. The trick to this is keeping the fiber soaked with primer by stopping every foot or so, pointing the ampoule downwards, and giving it another shake. The primer is colorless and nearly invisible, so it’s hard to check coverage visually; fortunately, a light coat is all that’s needed. When Thiel finished priming the top strip, he used a second ampoule for the bottom one. Then came the moment of truth: The actual adhering of the rails to the hull.
The adhesive in the bonding strips is tenacious, and you get only one chance to stick the rail in the right place. We started by pulling back about six inches of the peel-off film (like that on double-sided tape) from the top bonding strip and carefully aligning the first inch or so of the rail with the pencil marks. As soon as the bonding strip touched the primed gelcoat, it stuck like...well, like glue, although full cure takes up to 36 hours at 70F (the minimum temperature for installing Smart-Rails). While I supported the free end of the rail and gradually pulled off the film, Thiel aligned and pressed it into place.
The next step was to evacuate any air trapped under the bonding strips, using a small roller included in the Smart-Rails kit. Thiel made three passes along the rail, at the top, middle, and bottom of the strip, applying about 30 pounds of pressure. Then, working from aft forward, we attached the lower bonding strip in the same way, although my job was now simply peeling off the protective film; the rail was held positively by the glued-on upper strip. We then moved to the other side of the boat and installed that rail in the same way. All of this was quicker than it sounds: Installing Smart-Rails is as easy and straightforward as the instructions say it is, although it helps to go slowly in the planning and placement stages; once the rails are in place, errors become permanent.
This article originally appeared in the November 2006 issue of Power & Motoryacht magazine.