This tutorial is an example of how Lakeside Pottery Studio repairs and restores indoor stone / marble sculptures with heavy load bearing and narrow cross-section breakage needing greater reinforcement.
In this example, the marble sculpture broke by the very narrow ankles with about 60 lbs of load-bearing. Cementing-only would not have been sufficient and insertion of metal rods was required to ensure proper mechanical integrity.
Insert rod and turn a few times to ensure that epoxy touches all surfaces
Quickly wipe off excess epoxy with a rag and 91% alcohol
Mirror the rod orientation on the stone exterior wall to be used as a guide to drill side B correctly
Use pencil to mark the rods location
Drilling accurately on both sides of the broken pieces for proper alignment is tricky. There are more than one way to achieve accuracy and below is the option we chose for this project.
Insert soft clay in side A drilled hole
Flatten the clay as shown
Use acrylic paint to generously mark the clays center
Carefully place side B in place
Verify that the acrylic paint transferred from side A to side B
Before removing, continue the previously marked line to side B in the same projection
Side B hole should be wider than side A for easier fit
Drill a hole using the marked line as a guide
Start with a narrower masonry drill bit (3/16") for better control and accuracy
Drill with the next size (1/4")
Finish with a size larger than side A drilled hole (5/16")
After cleaning the drilled holes, verify fitting accuracy
Use touch to sense continuity at the points of contact
The shown epoxy has about two minutes workable time. Use slow cure epoxy if uncomfortable with 2 minutes
Ready for cementing
Apply epoxy to rods
Fill 2/3 of drilled hole with the mix epoxy
Apply epoxy to all surface carefully of side A and side B
Place the statue two part together
Do not wipe excess epoxy off to avoid smearing. Remove epoxy after the epoxy is set. It will be harder to remove if excess epoxy is removed when it is totally cured
