How to fix broken marble corner

What To Do To Repair Damaged Corners Of Marble (In 7 Steps)
“Marble” is generally one of the top three types of stone for use as surfaces, with most of the damage occurring at corner edges; typically on table/counter tops, along the edges of bathtubs or sinks, stairways and other. Marble is also very heavy, but the corners and edges can be damaged from the weight of a heavy object striking them, as opposed to any amount of weight they may be supporting. As long as the proper materials are used and the proper techniques are employed, most chipped corners can be completely repaired.

This article was designed as a guideline for homeowners to help them repair their own chipped and/or damaged marble corners, by employing the easy method that many Professionals in the Stone Restoration Industry have developed. The following method will improve the strength of the corners of the marble.

Causes Of Damage To Marble Corners
Because White Marble is a Natural Stone, the majority of its resultant structural mass is made of Calcium Carbonate; therefore, as when manufactured with thin edges, Marble is heavy and brittle. Most of the damage that is done to the corners of Marble occurs for one of the following 5 reasons:
1. Weight causing damage to the corner of marble. Weight is what actually causes damage, marginally or significantly, if sufficient to chip the edge;
2. Lack of support for the corner; (No support on edge, or overhanging);
3. Fixture movement;
4. Environmental movement;
5. Temperature variations.Marble that is not installed correctly has to be fixed
There may be cracks (natural fissures) on the edge of the marble.
Whether your marble corner has broken or not will determine how to fix it. Two types of damage occur when fixing the edge of a marble corner:
1. The corner has been clearly broken and can be repaired using the original piece.
2. The corner is missing and will need to be recreated.
Materials and tools for professional marble corner repair
If you intend to do a professional repair on your marble corner, you will need the following materials:
1. Razorblade, plastic scraper, or stone/marble repair adhesive (matching color)
2. Liquid Color (pigments)
3. Tape
4. Recovery (denatured alcohol)
5. Sandpaper: 400 – 2000 grit
6. Polishing compound
7. Polishing pad
We suggest using either two-part professional epoxy (for stone) or one-part construction adhesive to fix marble corners. The rationale is that construction adhesive will lose its color/yellow and become brittle over time, therefore reducing the lifespan of the repair.
After using the recommended materials, do not use construction adhesive again (unless using the typical construction adhesive for repairing marble corners).To begin with, you want to have the knowledge of the broken corner prior to doing anything to it, so you want to check for any visible damages before doing the repairs by visually inspecting the broken corner/edge of marble. For example, if the piece has been removed and replaced, and after replacing it appears as though it has never been removed, you can finish your repairs. If you do not have a piece of marble that is missing, or if a piece of a corner of a piece of marbles has broken off, then epoxy will be added to create a new corner; and after it cures, the new corner will be shaped so that it fits correctly with the existing marble.

To make sure the corners of your slabs are properly prepared for repairs, follow these steps:

1. Check the Slabs to Determine the Condition of the Slab
before beginning repairs on the slab or before making any modifications to structures supporting the edge of slabs there may be structural problems with the concrete that support the slabs. Check the slabs for Structural fractures that run completely through the slab requiring you to repair or provide additional structural support to the slabs.

2. Clean The Surface Thoroughly
Before performing a repair, clean the area where your marble repair will occur. Cleaning the area where you will perform a repair is very important to ensure the successful bond of the binders to the marble surface and will help ensure that the binders will be able to bond effectively during the bonding process. When cleaning an area where you are going to perform a repair, clean it with acetone and allow it to dry completely.

Note: Do not wet the area to be repaired with any liquid prior to applying epoxy as this could negatively affect the bond of the epoxy to your marble surface.

3. Test Fit the Broken Piece
If the broken marble piece has been received successfully, test fit the piece to ensure that the marble’s broken piece is properly aligned to your existing marble slabs with adhesive to adhere to.Verify on every side that the broken piece will fit with the slab for all angles before determining how to hold both pieces until they cure, possibly by using something such as masking tape.
The more accurately that you test fit the broken piece, the more likely the way that you repaired the marble will appear seamless when finished.
Step 4-Mixing and Applying the Epoxy
Mix both parts of the marble glue according to the manufactures instructions, and if you would like you can add pigments to create a perfect marble color match.
DO NOT GO OVERBAORD; DOING SO WILL MAKE PIGMENTING VERY DIFFICULT.
Create an even thin coating of marble glue on both surfaces to be glued together; otherwise, you will create too much glue that will squeeze out of the seam.
Carefully press together so that both pieces are aligned perfectly with the slab, and the downward force can hold both pieces in their correct alignment.
When both pieces are glued together use duct tape to hold them until the glue has gained enough strength to hold both pieces in their correct alignment.
You will have 24 hours from the time you laminate to finish before the epoxy is completely cured; that will depend on relative humidity and temp.The ideal working conditions for installing marble are within 20 to 25 degrees Celsius (68 – 77 degrees Fahrenheit). If any sanding we will be sanding corners or polishing corners during that period, then we will not be able to guarantee that the installation will cure properly (set), as curing requires proper environmental conditions.

Step 6: At around 30 to 60 minutes into the initial curing (after the epoxy cures to semi-hard), you may remove the excess epoxy using a razor blade. If you cannot remove the excess epoxy using a razor blade, you may also sand it off using sandpaper.

Step 7: Using 400 – 600 grit paper to sand the repaired corner, then moving up to 1500-2000 grit paper to polish the area repaired, will produce the original finish. Use a marble polishing compound to restore the high-gloss finish of the corner after sanding the repaired area. Do not sand too much, as this will change the shape of the corner profile. Use diamond polishing pads to polish high gloss finishes.

If an entire corner of a marble slab has broken off, make a temporary mold (with duct tape or plastic sheet) to use as a template for the fill material. Use knife-grade colored epoxy to fill the void (fill slightly above the void and shape it with sandpaper once cured). If the color of the filled void closely matches the surrounding color of the repaired area, you will have an invisible cosmetic repair.

Here are some ways to prevent future breaks in corners of marble:

Avoid any impact to or near the edge of any marble product;

Provide proper edge support for marble products that are overhanging;

Consider having rounded or beveled edges, as these edges will be less likely to break;

Add corner protectors (such as poster corners, bumper strips etc.) in areas with heavy foot traffic.

While sealing the marble product will not prevent breaks due to either structural failure, a seal creates a more durable surface.

When to call a professional

You should consult a professional if you have:

A broken corner that has a structural crack;

A broken load-bearing slab;

A large area of visible broken marble that requires repair;

A high-gloss finish that needs to be restored to its factory quality.

If you require repairs of this nature, consult the services of a professional stone restoration expert with the proper tools and equipment to provide repairs that are near invisible with vacuum bonding systems or with color matching compounds.

Final Thoughts

With the appropriate adhesive and method, most broken marble corners can be repaired. However, there are three primary elements to achieving an invisible repair: preparing the repairs properly; color matching the repairs to the surrounding repair area; and polishing the repairs to restore their original appearance.

If a marble corner is repaired using a high-quality marble epoxy system, it will be stronger, more durable, and will be visually indistinguishable from the original marble corner.