I had stainless rails made for the outside by TOP IN QUALITY INC.810.364.7150. Marysville MI. $197.00(back in 1998) for the pair.They were custom made to my measurments based on the average spacing. The nuts were welded in the short standoff pipes and I off set the inside rails by using a custom made stainless SEX BOLT. ie a 3/8" dia x 5/8 long hex headed bolt drilled out and tapped for 10-24 screw,add a fender washer, polysulfied caulk and they have NEVER leaked again. I also sealed the deck holes with epoxy during the operation to protect the core.One other note I epoxy sealed the TEAK hole so the screw wouldnt crush the wood when I tightened it.