Professional granite suppliers are usually experts at picking out pieces of granite that will create inconspicuous seams–they can often visualize the best cuts from a granite slab with just their eyes, and perhaps with the help of imaging software. Find a supplier you trust and rely on their expertise.
Smooth, straight, and properly aligned granite edges are the result of careful measuring and cutting with the proper saw, blade, and skill. Most DIYers don’t have the tools or the skills needed to cut granite properly, so it’s essential that you work with a high-quality supplier. Uneven or rough edges can be remedied, but once again it’s best to rely on your supplier to make these adjustments.
The goal here is simply to remove any dirt or dust before adding the epoxy.
Some epoxies claim that they don’t stick to polished granite, meaning you shouldn’t need tape. However, even in this case, it never hurts to go with the tape when you seam granite.
This also gives you the opportunity to take one more look at how well the 2 pieces match up.
2 pairs of suction cups and 2 turnbuckles should be sufficient for most countertop seams, but you can use 3 or more for longer seams. You can also buy or rent a tool known as a “seam puller” or “seam setter” that uses vacuum pumps to pull and hold the granite pieces together. If you choose one of these, follow the instructions for proper use. [6] X Research source
Make sure the suction cups stick well to the granite. Try moistening the underside of each cup with a damp fingertip if needed. After you apply the 2-part epoxy to the seam, you’ll tighten the turnbuckles to pull the pieces of granite tightly together.
You can also mix up several test batches of tinted epoxy before deciding on a mixture. Blend together lighter and darker shades of a single tint color, or blend multiple tint colors. Let the tinted epoxy dry for 15-20 minutes, then determine the best match.
Stir the hardener into the resin thoroughly with a small putty knife. 2-part epoxies don’t become adhesives until they are mixed, but they harden quickly after being mixed. You’ll have 10 minutes or fewer to work with the mixed epoxy before it hardens.
Apply a thick enough layer of epoxy so that there are no gaps along the facing edges. However, you don’t need to plop on huge globs of epoxy—the excess will just get squeezed out when the pieces are pulled together anyway.
If you’re using a “seam puller” or “seam setter,” follow the product instructions for use. Once the 2 pieces of granite are drawn together, make sure they are even and level with each other. If necessary, you can use your hand or a soft rubber mallet to make minor adjustments. [11] X Research source
You don’t have to remove every bit of excess epoxy right now, but it’s easier to remove most of the excess now, before it dries.
Some epoxies may take longer to dry in humid conditions, so consider extending the drying time on a hot and sticky day.
The sharper the razor blade, the easier it will be to scrape off the dried epoxy. So don’t try to reuse a dulled blade for this job.
After the acetone evaporates, you can spray on a granite polish, then buff it according to the product instructions.
