The way I am doing it, right or wrong:
Locate your bolt positions and drill through the deck.
Set the fitting and tape around it with masking tape.
Remove fitting and apply a bead of 4200 around the perimeter of the unmasked
area and around the bolt holes. (5200 is to hard to remove without damaging
the deck down the road.)
Through bolt the fitting with a backing plate at least as large as the base
of the fitting. (I am using 1/4" 5083 aluminum because I have a lot of it
and it is easy to cut and drill.)
Tighten down the bolts just a turn or two past finger tight.
Remove the masking tape, clean up and let the 4200 cure for a day.
Tighten down the bolts fully so that the cured 4200 is in compression.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Thomas Wentworth" wrote in message
news:eEvvf.4$%W3.0@trndny07...
In my former life as a sailboat Captain [ that mean's I paid the bill for
the loan ] I never had to replace, rebed, or reattache, or put on new
.......... hardware. Things such as cleats, winches, etc.

Could someone tell me the correct way to go about doing this with a
fiberglass boat.

Say, a cleat. I understand that there must be a screw, or whatever that
goes into the deck to hold the cleat in place,,,,, what about sealing the
deck. And, on the inside of the deck [ below ] is there a backing plate
that the fastener of the cleat goes down through? What type of bedding is
proper.

Just a quick go through.

Thanks ,,,