schock makes a beam that you can glass into place. Not a small job though, be prepared for some long days in the boat. The beast doesn't fit nearly as well as it could. You could potentially use a thinner steel plate?

:: I am in the middle of restoring a Santana 22 that I
:: recently bought (1968, hull #365) and upon removing the
:: chainplates I discovered that the 2"x10" laminated
:: stringer that runs under the mast was thoroughly
:: water-logged and mostly rotten. I cut away the interior
:: fiberglass and removed the decaying stringer and
:: discovered what was left of a 5x9" aluminum inset plate
:: directly beneath the mast that had mostly turned to
:: paste.

:: I guess I have two questions; I was wondering if anybody
:: has experience and could give me some advice on
:: laminating and installing a new stringer; and what
:: should I replace the 5x9" plate with--stainless seems
:: like a better way to go, but it appears to have been
:: nearly a half inch thick. Any help would be much
:: appreciated.

:: Thanks,
::
:: Steve