Fixing Decayed (Rotted) Wood Using an Epoxy Penetrant and
Filler

When you come across rotted wood in your old house projects, instead of replacing the damaged wood, you also can repair it with specialty epoxy penetrants (also called consolidants) and fillers to make repairs. Not only is this faster, but the fixed wood is stronger than the original. For example, if you are fixing an old window and you strip the wood, paint on an epoxy penetrant. This will not only strengthen the wood, but also give it complete protection from moisture for decades once it is primed and painted.

About Epoxy Consolidants (Penetrants) and Fillers.

These products restore rotted, severely damaged windows, columns, frames, broken furniture, structural and decorative wood components. They are especially valuable for parts that cannot be replaced because of size, shape or other reasons. The objects restored with these products become fully functional parts often stronger and far more durable than the original.

The penetrants. Reinforces, rebuilds, water- and insect-proofs wood by hardening after penetrating. Regenerates rotted windowsills, frames, structural and decorative parts, furniture, boats, columns, floors.

Epoxy fillers are a structural adhesive putty and wood replacement compound. They are a high-strength no-shrink adhesive paste to fill, repair and replace wood and other materials in structures, walls, floors, furniture, sculptures. They are unaffected by water and insects.

We use Abatron's wood restoring products. It is better to use a product specially formulated for wood even if it is more expensive. Product information below. Note: Only buy enough for a year as the components degrade over time

Here are two examples of how we used an epoxy penetrant and filler to fix damaged wood.

Repairing Decayed Siding

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After we removed the paint from our siding, we came across some boards that had decayed. One end was soft enough to push a pencil through. Instead of removing the 16' siding, we decided to rebuild the bad end using an epoxy consolidant to harden the soft wood.
We drilled a series of holes one inch apart and half way though the wood. We then mixed the epoxy and painted it over the bad parts of the wood. We also used a syringe to inject the consolidant into the holes.
Original decayed wooden siding

Decayed siding

Here you can see the hardened wood. A piece of aluminum flashing has been pasted behind the board.
decayed wood siding treated with an epoxy consolidate

Siding hardened with epoxy consolidant

After the consolidant hardened, we used epoxy filler to reshape the missing parts of the siding. We didn't worry about creating an exact straight edge as the siding is old. We put wax paper behind each area to be filled so that the epoxy filler wouldn't bond to the board behind it.
decayed wooden siding treated with an epoxy filler
Epoxy filler used to fill in holes
The final painted siding is now fixed. It maintains its weathered look and will last as long as the other siding.

The finished siding

Fixing a Corner Post on Stone

Click to enlarge
We came across a wooden post that rested on a stone wall. It had decayed because water would sit on the stone and flow under the siding. The photo shows this post corner section resting on a flagstone wall. We cut out the bottom wood under the corner post and replaced it with a new piece of wood. We then painted the bad and good wood with an epoxy penetrant.
rotted corner post

Decayed post

Once the post was fixed, we had the problem of keeping water from getting back under the siding. If we simply caulked along the siding and stone, over time this seal would break and water would seep in. Instead, we purchased lead flashing from a roofing store and used it to act as a seal behind the siding and over the stone. Lead sheeting is both attractive and easy to work with. It also can be soldered using your plumbing soldering iron.
corner post using lead flashing

Siding replaced and lead flashing inserted behind the siding and wrapped over the stone

Product Information:

Abatron's LiquidWood and WoodEpoxleave site

Advanced Repair Technology Inc.leave site

Rot Doctor's Penetrating Epoxy and FILL-IT™ Epoxy Fillerleave site

Additional Information

Wood rot repairleave site

Purchase Abatron Epoxy Products
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