epoxy repair
Steps // How to Repair Rotted Trim with Epoxy
1 ×

Remove Rot-Softened Wood

 
Step One // How to Repair Rotted Trim with Epoxy

Remove Rot-Softened Wood

epoxy repair
Photo by Brian Wilder

After clawing out the loose stuff with a hammer, Stahl removes all the rot-softened wood with a die grinder and core-box router bit. For an epoxy repair to be effective, the freshly exposed wood has to be sound and dry—less than 18 percent moisture content. Stahl checks it with a moisture meter before proceeding.

 
2 ×

Inject Borate Into Holes

 
Step Two // How to Repair Rotted Trim with Epoxy

Inject Borate Into Holes

Inject borate wood preservative into holes
Photo by Brian Wilder

The undisturbed area at the bottom right of the mullion is an old epoxy repair, around which the wood continued to rot. To ensure that won't happen again, Stahl injects a borate wood preservative into holes drilled halfway into the wood. Sealed over with epoxy, the borate penetrates the wood, minimizing the chance of future decay.

 
3 ×

on the exposed wood

 
Step Three // How to Repair Rotted Trim with Epoxy

on the exposed wood

Brush epoxy primer on the exposed wood
Photo by Brian Wilder

A two-part epoxy primer brushed on the exposed wood ensures that the final repair will bond to the surface. After waiting about 15 minutes for the thin liquid to penetrate, Stahl wipes off the excess with a paper towel. The surface is now ready for a coat of the two-part epoxy filler.

 
4 ×

Blend the Resin and Hardener

 
Step Four // How to Repair Rotted Trim with Epoxy

Blend the Resin and Hardener

Blend the resin and hardner
Photo by Brian Wilder

Stahl pumps the two components of the epoxy filler—resin and hardener—onto a plastic board, then blends them thoroughly with a plastic putty knife. Epoxy doesn't stick to hard plastic surfaces, so the board and putty knife can be cleaned and reused.

 
5 ×

Sculpt the Epoxy

 
Step Five // How to Repair Rotted Trim with Epoxy

Sculpt the Epoxy

Sculpt epoxy into shape
Photo by Brian Wilder

Using the same plastic putty knife, Stahl sculpts the viscous epoxy into shape. The mix remains workable for about 30 to 45 minutes (longer in cool weather and shorter when it's hot).

 
6 ×

Paint the Epoxy

 
Step Six // How to Repair Rotted Trim with Epoxy

Paint the Epoxy

paint the epoxy
Photo by Brian Wilder

Epoxy breaks down in sunlight, so it needs to be painted. The next day, after the repair hardens, Stahl sands it smooth, first with 80-grit paper, then 100-grit, then 220-grit. An acrylic primer is next, followed by two coats of 100-percent acrylic paint.

 
 

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