The best epoxy resin crack filler depends on the material and the repair: MAS Black Epoxy suits decorative wood cracks, Akona is made for concrete and foundation cracks, and PC Products PC-Concrete is designed for concrete crack repair and anchoring. Boncart’s moldable putty is better for patching and bonding varied materials. Compare the products below by application, finish, and working format before choosing.
| Product | Best For | Format |
|---|---|---|
| MAS Black Epoxy Resin, 16 oz | Wood cracks and decorative inlays | Self-leveling liquid |
| Akona Epoxy Crack Repair | Concrete and foundation cracks | Injectable liquid |
| PC Products PC-Concrete | Concrete cracks and anchoring | Two-part paste cartridge |
| Boncart Epoxy Putty | Multi-material filling and bonding | Two-part moldable putty |
| MAS Black Epoxy Resin, 32 oz | Larger wood projects | Self-leveling liquid |
MAS Black Epoxy Resin, 16 oz
Best for: Woodworkers filling knots, cracks, and voids with a bold black finish. This pre-pigmented epoxy provides an opaque, jet-black color without requiring added dyes or pigments. Its dual-purpose formula is described as suitable for both filling voids and coating surfaces, with a self-leveling, high-gloss finish.
Choose this if the repair is part of a river table, wood slab, bar top, countertop, or decorative inlay. The 16-ounce size is a smaller listed option than the 32-ounce version, making it a relevant choice when the project calls for less material. Limitation: the opaque black color is not intended to blend invisibly into natural wood.
Akona Epoxy Crack Repair
Best for: Homeowners addressing cracks in concrete, brick, or foundations. Akona is a clear liquid epoxy crack filler described for horizontal, interior, and exterior repairs. The listed features also say it can stop air and water leaks and that the cured repair is stronger than concrete.
Choose this product when the repair needs a liquid epoxy intended for masonry cracks rather than a decorative wood finish or a sculptable patch. The product is described as injectable and designed for a no-mess application. Limitation: the listing provides limited detail about application steps and crack-size requirements, so confirm that its method suits the specific repair before starting.
PC Products PC-Concrete Epoxy Paste
Best for: Concrete repairs that may also involve anchoring hardware. This two-part gray epoxy paste is listed for filling concrete cracks and anchoring threaded rods, bolts, and dowels in concrete, grout-filled block, and unreinforced masonry. Its high-tack paste resists moisture and can be used vertically.
Choose it if a paste consistency and anchoring use are more relevant than a self-leveling finish. The listed application temperature range is 35 to 115 degrees Fahrenheit; its service temperature range is -20 to +115 degrees Fahrenheit. It is specified for indoor and outdoor use. Limitation: it is gray paste, not a clear or decorative wood-filling resin.
Boncart Multi-Purpose Epoxy Putty
Best for: Repairs requiring a moldable filler for different materials, such as metal, plastic, stone, wood, tile, ceramic, or glass. Boncart’s gray two-part putty is intended for filling, bonding, and sculpting. The instructions say to mix equal parts, knead until gray, and apply within 30 minutes; full cure is listed as 24 hours.
Choose this if you need to shape a patch rather than pour a liquid resin into a void. Its features also describe it as waterproof and suitable for plumbing or pool repairs. Limitation: the listing specifically says to avoid using the putty underwater, so it is not a choice for an in-water repair.
MAS Black Epoxy Resin, 32 oz
Best for: Larger woodworking projects that need an opaque black filler and high-gloss coating. Like the 16-ounce option, this pre-pigmented resin is designed for cracks, knots, voids, wood slabs, river tables, countertops, and other woodworking projects. Its self-leveling formula is intended to spread evenly across a surface.
Choose the 32-ounce size over the smaller MAS option when the project requires more material. The two versions share the same listed finish and applications, so the main stated difference is package size. Limitation: its black color is a deliberate design choice and may not suit repairs where a clear or wood-matched appearance is needed.
Buying Guide: How to Choose an Epoxy Crack Filler
What material are you repairing?
Match the filler to the repair surface. For decorative wood cracks and voids, a self-leveling resin such as MAS Black is designed to fill and coat. For concrete or masonry, compare Akona’s injectable liquid with PC-Concrete’s paste. For mixed-material patching or shaped repairs, a moldable epoxy putty may be more practical.
Do you need a liquid, paste, or putty?
- Liquid epoxy: Consider it for cracks or voids where flow and leveling matter. Confirm that the application method fits the crack.
- Epoxy paste: Consider a high-tack paste for vertical work, concrete repairs, or anchoring tasks.
- Epoxy putty: Choose a moldable format when you need to shape or sculpt a patch. Check mixing and working-time instructions.
Does the appearance matter?
MAS Black is opaque and high-gloss, so it creates a visible black accent rather than a transparent repair. PC-Concrete is gray, and Boncart putty is also gray. For repairs where color matching is important, check the product’s tinting or finishing options before buying.
What application conditions should you check?
Review the instructions for surface preparation, application temperature, working time, curing time, and whether the repair can contact water during application. Product claims about waterproofing do not necessarily mean that a product can be applied underwater. Follow the specific label and instructions for the repair.
Frequently Asked Questions
Which epoxy crack filler is best for wood?
MAS Black Epoxy is the most directly suited option here for wood cracks, knots, voids, and decorative inlays. Its finish is opaque black and high gloss.
Which product is designed for concrete cracks?
Akona Epoxy Crack Repair and PC Products PC-Concrete are both listed for concrete crack repair. Akona is an injectable liquid; PC-Concrete is a paste that can also be used for anchoring.
Can epoxy putty be applied underwater?
Boncart’s product information says to avoid using its epoxy putty underwater. Check the chosen product’s instructions rather than assuming that waterproof claims allow underwater application.
How do I choose between the 16-ounce and 32-ounce MAS options?
Both listings describe the same black, self-leveling applications. Choose based on the amount of material your project calls for.
Is a liquid epoxy or putty better for a crack?
A liquid is better suited to applications where flowing and leveling are important. Putty is better when you need to mold or shape the filler. Match the format to the crack and follow the product instructions.