: . . . the stainless thumbscews (which are hard to find) are from
: www.microfasteners.com . (they are a special order even from them, so
: you'll have a minimum of 20 pieces).

: Comments & suggestions, welcome, Derek

You can get small quantities of stainless steel thumbscrews fro McMaster-Carr (www.mcmaster.com)

Search at the first page of their site for "stainless thumb screw" and you'll get a list of several varieties. The ones I'm talking about here are on page 2874 of their online catalog.

the kind you are using are called "spade head" thumbscrews, and McMaster-Carr sells them for $5.31 for a box of 5.

You can also et these in brass at $7.55 for a box of 5.

Unlike a hex-head bolt, which applies pressure with the head of the bolt, plain thumbscrews are usually used as set screws, with the tip of the threaded end pressing on something. You added a washer under the spade head so that it would be the pressing point. There are thumbscrews made with a shoulder that would replace that washer in some cases and in other cases they would provide a nice bearing surface riding on the washer. (Since you are tightening down wood hatches you probably want to keep that washer so the pressure is spread out a bit.)

Pictured below is one of these thumbscrews with a shoulder. They are slightly cheaper than the plain thumbscrews at $4.95 for a box of 5.

If you drill a small hole through the spade head of any of these thumbscrews you can thread through a short length of string or monofilament fish line, which can be secured with a knot. Or, tie the string loosely around the bolt section of the thumbscrew, and it should stay in place between the washer and the spade head of the thumbscrew -- at least as long as the neoprene gasket keeps the washer on.

The other end of the string can be tied to a deckline, or glued or tied to a spot on the hatch or the deck near the thumbscrew. A drop or two of epoxy should do. Keep these strings short -- just long enough to screw and unscrew the thumbscrews.

Hope this helps.

PGJ