Introduction
Not all wood can be saved. When decay has gone too far—when it crumbles under light pressure or smells of rot—it’s time to cut out the bad and rebuild the structure. This blog walks you through how to safely remove rotted wood, rebuild missing areas, and prepare the surface for long-term durability using Epoxy.com Products #12, #899, and #2005.
When Consolidation Isn’t Enough
Epoxy consolidants are designed for structurally sound but weakened wood.
If the wood is:
- Soft and spongy to the touch
- Darkened or blackened from fungal rot
- Easily gouged with a screwdriver
What You’ll Need
- Chisel or oscillating tool (for clean removal)
- Wire brush or coarse sandpaper
- Product #12 (for dry wood) or #899 (for slightly damp wood) – consolidating primer
- Product #2005 – 100% solids epoxy binder for mortar repairs
- Product #10 Mortar – Trowel-grade epoxy patching material
- Optional: Clean, dry silica aggregate for custom mortar blends
Step-by-Step Repair Process

1. Remove All Rotted Material
Use hand tools or saws to remove all visibly rotted, spongy, or moldy wood. Cut back to firm, dry material. Do not attempt to epoxy over active wet rot or dry rot.
2. Clean and Shape the Repair Area

Use a wire brush or coarse sandpaper to clean and roughen the surface. Square or undercut edges provide better bonding than shallow bevels.
3. Prime With Consolidating Epoxy

Before patching, consolidate and prime the exposed wood using:
- Product #12 for dry surfaces
- Product #899 for slightly damp or moisture-prone wood
Let it soak in and cure as directed.
4. Rebuild With Epoxy Mortar
Once the primer has cured:




Tool flush or slightly proud of the surface. Epoxy mortars are difficult to sand once fully cured.
5. Finish and Coat (Optional)
Example Applications
After the patch cures, you may apply an additional coat of #12 or #899 for sealing, or topcoat with paint, stain, or other finishing systems.
Rotted window sill:
Cut back to solid wood, prime with Product #12, then fill with Product #2005 or Product #12 and silica sand Mortar.
Decorative trim with soft spot:
Excavate the damaged area, consolidate with Product #12, and rebuild using a custom mortar mix made with Product #2005.
Dock board edge with water damage:
Trim back the affected edge, prime with Product #899, and patch with Product #10 Mortar.
Column base or porch post:
Remove all rot, consolidate with #12 or #899 as appropriate, then form and pour an epoxy mortar patch using Product #2005.
Tips & Warnings
- Never apply epoxy over saturated, rotting, or fungal-infected wood
- Always consolidate first with #12 or #899 before patching
- Epoxy is permanent—shape and tool before full cure
- Confirm compatibility if you’re topcoating with a different system
- You can also add a replacement wood member:
Use Product #2005 between the original wood and the new section to create a flat, high-strength bearing surface.
While mechanical fastening is still recommended, the epoxy bond ensures the new piece acts as though it were part of the original structure.
Conclusion
When wood is too far gone to consolidate, you can cut it, rebuild it, and seal it—permanently. With Product #12 or #899 for priming and Product #2005 or #10 Mortar for patching, Epoxy.com provides everything you need for professional-grade restoration.
Contact:
For more detailed information
Contact Us Today:
📞 Call: 321-206-1833 (orders)
📞 Technical Support: 352-533-2167
📧 Email: sales@epoxy.com
🌐 Visit: www.epoxy.com
Posted by Norm Lambert