How to Create a Butt Joint Seam in Stone

First, make a mirror cut, clean, and pre-align the slabs.
For an example of how to make a perfect mirror cut seam, see our video tutorial for how to make perfect seams.

 

Tip:

Use a glue that is a similar color as your stone.
 

Procedure Steps: 
Step 1: Use a blade on a right-angle grinder to cut matching notches in the edge of the slab at the seam, to a minimum of half a washer deep. Dry fit to make sure washers fit before adding glue!
Step 1 detail: Create matching notchesStep 1 detail: Create matching notches Step 1 detail: Close up of notchStep 1 detail: Close up of notch Step 1 detail: Notches should be a minimum of half a washer deepStep 1 detail: Notches should be a minimum of half a washer deep
Step 2: Fill the notches with glue, and place glue all along the seam.
Step 2 detail: Fill notches with glueStep 2 detail: Fill notches with glue
Step 3: Insert the washers into the glue-filled notches.
Step 3 detail: Apply glue to the entire seam, insert washersStep 3 detail: Apply glue to the entire seam, insert washers
Step 4: Butt the two slabs together, and clean off excess glue.
Step 5: Use a seam leveling device, such as one of the seam setters from Omni Cubed, to level the seam and tighten it together. To verify the seam is smooth, use a razor blade sliding across the seam from both sides to check that there are no ridges.
Step 5 detail: Use a leveling deviceStep 5 detail: Use a leveling device Step 5 detail: Use a razor blade to check the smoothness of the seamStep 5 detail: Use a razor blade to check the smoothness of the seam Step 5 detail: Final leveling checkStep 5 detail: Final leveling check
Step 6: While glue is still wet, clean off any further excess glue with acetone.
Step 6 detail: Clean off excess glue while it's still wetStep 6 detail: Clean off excess glue while it's still wet Step 6 detail: Use acetone to clean off the excess glueStep 6 detail: Use acetone to clean off the excess glue
Step 7: Allow glue to fully cure.
Step 7 detail: Let hardenStep 7 detail: Let harden

Step 8: After glue has fully hardened, remove the leveling device. Then apply double thick masking tape to both sides and fill seam with knife grade glue.

Step 9: Let the glue harden for 15 minutes.

Step 10: File down excess glue with a razor blade.

Step 11: Buff with 000 steel wool, and the Butt Joint is complete.