posted 05-05-2002 09:17 AM ET (US)        

'Just drill the proper size hole for the screw type snap and make sure that you countersink the hole and seal it before screwing in the snap. The counter sink should help prevent the gelcoat from expanding when the screw goes in and, in turn, prevents the spider cracks.'

I am familiar with the counter sink concept as it relates to carpentry, but I'm a little unsure about what he means here, and how it is accomplished.

Thanks for any help.

posted 05-05-2002 12:06 PM ET (US)            

Keep your fingers crossed... If you already have a full Mills enclosure (top, side curtains, aft curtain and windshield, you may be lucky. If you don't have a full enclosure, oh well, my advice won't help.

When I got my Mills Bridge cover for my 1990 Revenge (Cetacea 44) a few years ago, all the snaps that were already in place for the full enclosure fit the bridge cover perfectly. Even though the cover came with snaps, I didn't have to use any Mills snaps or drill any holes. I did have to adjust a few of the sliding snaps on the windshield, but all the snaps that screwed into the fiberglass were already perfect.

Your cover may take a few months to "stretch" and reach all the snaps. Mine did. For the first season I couldn't get the final 1 or 2 snaps on one side or the other to snap. Keep working at it. When you get the final snap, its a victory! All my snaps have worked for the last few years, and the cover is tight.

posted 05-05-2002 01:13 PM ET (US)            

It is the same thing done with the same tool.

The only difference is that rather than countersinking far enough so the flat of the screw head is flush with surface around it, you are only going to counter-sink your drilled hole far enough so the diameter of the countersink at the surface of the gelcoat is greater than the diameter of the screw threads; the diameter of the counter-sink as it passes through the back of the gelcoat and gets into the fiberglass (you can see the color change from off-white to kind of a green) should be awfully close to the diameter of the screw threads if not as big.

The notion is that the drilled hole is always a little undersize so as the screw is driven, its threads bite into the fiberglass to make the fasten. Problem is, if you don't oversize the hole as it passes through the gelcoat, the gelcoat being on the surface, and not having the same properties as the fiberglass, will chip or spider-crack if you don't relieve the opening.

Try it slowly at first, and you'll quickly get the feel for it.