Bonstone Crack Repair 28 Medium-Viscosity Epoxy, 450 mL

Description

Bonstone Crack Repair 28 epoxy is a two-part, medium-viscosity cartridge system for filling wide horizontal cracks in stone. It flows into the repair area while remaining thicker than lower-viscosity injection products, giving restoration crews more control when a crack needs penetration without a water-thin material.

Stone and Concrete Repair Applications

The material is intended for horizontal crack work where gravity can help the mixed epoxy enter the opening. Typical uses include natural-stone repair, fabrication touchups, and bonding new concrete to existing concrete in properly prepared areas. The repair surface should be clean, sound, and free of loose particles, oil, standing water, or dust that could interfere with contact.

Crack width, depth, and access determine how the cartridge should be positioned. A compatible small long nozzle helps place mixed material into the opening, while a dual-cartridge gun keeps both components moving through the mixer together. Start with a fresh nozzle, purge the first small amount until the blend is uniform, and work from the deepest practical point toward the surface to reduce trapped air.

Cartridge Setup and Finish Control

The 450 mL cartridge uses a 2:1 mix ratio by volume. Confirm that the dispenser, plungers, and mixer all match that ratio before opening the cartridge. The epoxy can be colored with compatible liquid tints when the repair needs to blend with surrounding stone. Test the tint in a small batch first, because stone color and lighting can change how a cured repair appears.

Plan the repair before attaching the mixer. Dry-fit the nozzle into the crack, identify where excess material can escape, and protect finished stone next to the work area. For a long crack, divide the work into manageable sections so the nozzle can remain close to the active fill point. Do not force a partially cured mixture through the nozzle. Rising trigger pressure can indicate a blocked mixer or material beginning to set.

After placement, inspect the surface for low spots and air pockets while the material can still be adjusted. Remove uncured residue using the approved cleanup method for the substrate and keep tools from spreading epoxy across porous stone. Let the repair remain undisturbed through the required cure period for the actual temperature and joint depth. A small sample prepared with the same tint and mix setup can help confirm the finished color before a highly visible repair proceeds. Record the mixer, tint amount, surface preparation, and cure conditions when a repeatable shop repair process is required.

Specifications

Browse related epoxy adhesives for stone bonding, patching, and assembly work. General product-family information is available from Bonstone. Match the cartridge to the correct gun and nozzle before beginning the repair.

Need Help?

Need help matching a crack profile, cartridge gun, tint, or mixer? Call (800) 220-1966 or email [email protected] with the stone type and repair dimensions.