Hi Don,
I'm at work now, so I don't have time to write too much, but the tabbing I am referring to is basically using strips of
fiberglass cloth/reinforcement (often referred to as "tape") to attach things to the hull. You use the tape along with epoxy resin.
Tabbing prefers gradual bends, so you often "fillet" an inside right angle bend, to eliminate the sharp inside corner. Tabbing can do a few things, for example:
1) It can attach two things to each other
2) It can spread point loads
3) It can make a monocoque structure stronger
Basically, imagine taking a piece of 2" wide masking tape and joining two things together with a long, lenghwise piece of it. Substitute fiberglass and resin for the masking tape and you have tabbing.
Here are a couple of photos. In the first photo, you can see the tabbing below and to either side of the "5"; and in the second, you see a wooden bulkhead tabbed to a fiberglass hull. Done properly, these are very strong bonds (they hold boat bulkheads in place and they take a lot of loading).
I just decided to add one more, because it shows what a fillet looks like. It's the white material in the corners. This is made with thickened epoxy. It keeps the tabbing from making a disagreeable sharp corner (it prefers gradual ones), and also helps to spread loads.
I should also mention that tabbing is different from epoxying in a mounting block, or etc. as some people are showing. Tabbing is used for making connecting bonds, such as if you were going to "tab in" your upper cabinets instead of riveting them. Of course blocks can also be mounted with fiberglass, but that's not usually referred to as tabbing.
I will try to get you more information tonight or tomorrow.
Raya