Welcome to iBoats . . .
Tell us a bit more about your restoration and post some pictures of the project, if you can. Having a good visual always helps with responses.
As for bedding the stringers, most common is 'peanut butter' which is a mixture of resin and fiberglass bits to form the consistency of . . . you guessed it . . . peanut butter. There are other methods as well (adhesives, etc). A major consideration is to spread out the contact area so as not to create a hard spot on the hull.
There are many threads of boat restoration so you can browse around and learn from other's experiences.
Maybe start a thread in the restoration forum with some of the details of your restoration . . .
