Les,
Yes it can be repaired, but wouldn't you rather make a new top? I would....
That being said, here is how you do the repair:
Place slab as it will be once installed. You need to tape off the bottom of the cracks/holes so the "fill" stops when it hits that barrier. You should then tape all the way around the crack to build a dam. The tape should be placed within 1/8" of the crack, closer if possible. You need to get a penetrating epoxy (see link):
http://www.defusco.com/stoneweld-crack-filler-epoxy-24oz-p-1982.htmlAfter color testing it on the stone to make sure it doesn't color enhance the stone you need to fill the dam with this epoxy, allowing it to penetrate through the crack right to the bottom. This will seal the crack off and strengthen the stone so the crack will not get larger. Once the epoxy has cured (think 24 hours), if there are still large gaps I would fill them with either epoxy or a polyester resin:
http://www.defusco.com/tenax-knife-grade-polyester-liter-p-1432.htmlDo not fill all the way to the very top as we want to put on a top coat with color to match the base color of the granite:
http://www.defusco.com/6pc-tenax-poly-color-kit-p-1439.htmlThis glue will dry with a polish to it. If it does not match the gloss of your stone simply use steel wool and buff it out.
When finished with the installation, seal with an impregnating sealer like Hydrex:
http://www.defusco.com/tenax-impregnator-and-sealer-liter-p-2095.htmlWe actually have a DVD that shows how to do this stuff, it is called "Fabricating Stone for the Do-It-Yourselfer - GLues & Sealers". Here is the link:
http://www.defusco.com/fabricating-stone-for-the-doityourselfer-glues-sealers-p-2299.htmlGlad to be of service,
Mark
