The blank shoulder of the lag screw is roughly equal to the thickness of the sump floor. I counter-drilled this out to the thickness of the shoulder to prevent it from binding. Note: this was true for my '84 boat. Other years, you'll have to measure. In any case, you would want to counter-drill for the length of the shoulder.
Art Herrick #5468 Sea Change ----- Original Message ----- From: James Calleran To: [email protected] Sent: Sunday, July 06, 2008 4:32 PM Subject: catalina27-talk: More on SS Lags in Keel To Mike and others who have installed SS lag screws in their keel, After drilling through the bilge and into the keel, what did you do (if anything) to treat the hole in that first few inches of glass and plywood before you actually get into the keel? And, how much of that 8" screw is taken up with the plywood and glass? Or, asking a different way, how much of the lag screw actually is biting into the lead keel? Fair Winds, Jim Calleran, C27 #2784, Trad, OB Mathews Yacht Club, VA 37°27.8'N/76°18.6'W --- On Mon, 6/23/08, Mike Provost <[EMAIL PROTECTED]> wrote I installed a single lag screw in mine....as a precautionary measure.
