Word around the docks these days is that, still, there’s no way to easily bond King Starboard—a poly product popular with today’s boat builders and restorers—either to itself or to other surfaces, whether wood, metal, fiberglass, or whatever. Oh sure, there are a couple of adhesives kicking around these days that will actually bond Starboard to itself but, prior to using them, extensive preparations are necessary. More to the point, the surfaces involved must be first abraded with medium-grit sandpaper. Then they must be thoroughly cleaned with a solvent like acetone, Toluene or alcohol. Then finally, they must be flame-treated, meaning a propane torch must be applied in a highly specific and complicated way. Scorching (and possible discoloration) is always a possibility and the bonding process has to occur less than an hour after the flame treatment.
So hey, the reality is that, when faced with doing so much to simply stick two things together, many a weekend warrior has concluded, “Maybe I’ll just use screws or bolts—to heck with adhesives.” And why not?
But just last year, an alternative surfaced; a straightforward little product that seems to robustly—and I do mean robustly—bond Starboard but demands no complicated prep or materials. Called Chem-Set 6105 by Pennsylvania developer Chemical Concepts, it’s a two-part, 1:1 toughened acrylic adhesive specifically formulated to bond polypropylene and polyethylene (King Starboard) with no primer or surface treatments required.
Of course, purported ways of addressing what has always seemed like Starboard’s Achilles’ heel have been numerous and uniformly unsuccessful over the years. So, before even mentioning Chem-Set 6105 in print, I put it to a real-world test.
My method was simple. As you see in the photos above, I cut two small, three-inch-by-one-inch strips of quarter-inch Starboard, mixed up a little of the two-part Chem-Set, smeared a bit of the gelatinous stuff across one of the strips with a plastic spoon, and then squeezed both strips together with my fingers. At the behest of Rick Firrera, product manager of Chemical Concepts, I waited about two days for a complete chemical cure before testing the strength of the bond.
The result? Although I’d very casually applied the adhesive to just one of the Starboard strips instead of both, (and used no clamps or other mechanical means to press the strips together) the bond the Chem-Set produced was so strong I could not break it no matter how hard I tried. Indeed, even when I secured one end of my two-part Starboard construct in a workbench vise and attempted to separate the two parts using a set of Vice-Grips, I only succeeded in imparting a serious bend in the construct.
Find Chem-Set 6105 at: https://www.chemical-concepts.com/chem-set
This advice previously ran in Power & Motoryacht magazine.