The Rot Doctor


Subject: rotting sills
Date: Tue, 14 Sep 1999

Hello Doctor:

I have old window sills (circa 1890) in pretty bad shape, but I really don't want to replace them. Most just have big cracks in them, but 1 has a chunk of wood missing.

What products would I need to stop any decay, smooth out the rough, cracked sills, and fill out the sill with the missing piece?

Thanks for your advice.



First remove any paint or other finish. Remove any loose pieces of rotted wood. Apply CPES (Clear Penetrating Epoxy Sealer) generously to the entire area, allowing it to flow into the cracks and holes. Give the wood all it will accept. Wait 3-4 days for the carrier solvents to evaporate away and for the epoxy to start to cure.

Now, for the sill with the missing piece, the easiest/least expensive way is to cut a piece of wood more or less to the proper size, coat it with CPES (especially the end-grain) for future rot protection, and then use our Epoxy Filler to fill any gaps around the replacement wood. After 24 hours cure time, sand smooth and paint.

For cracks and crevices, use the Epoxy Filler to fill, sand and paint. The Layup & Laminating Resin can be used only if you believe there are deep locations that you cannot get to with the filler. In this case, use a kitchen baster or similar implement to apply the L&L Resin to the cracks, allow it to flow in, give it 24 hours to cure, and then come back with the Epoxy Filler to do a final fill prior to sanding and finishing.

Once the window sills have been treated this way they are rot free and extremely resistant to future rot problems.

How much product you will need will depend on how many windows you plan to treat and what the volume of final filled area is going to be.

Come back if you have additional questions.