The Rot Doctor


Subject: Rotted wood solutions (paint won't stick)
Date: Mon, 01 Nov 2004

I live in Dayton, Ohio. My house was built in 1914. I have an area of wood trim that has some wood root. This area has a southern exposure and gets a lot of sun. I have problems getting paint to hold on the trim. I have tried other wood repair solutions and they release from the rotted surface. About 2 years ago I stripped, primed and repainted the surface and it is now peeling. I am looking for a product recommendation to fill the rotten areas, and repaint. Also I would like the paint to last for a least 7 to 10 years. What product options do you recommend?


Lance R.


CPES and Fill-It should take care of any areas that are currently rotted. If practical, dig out any loose crumbly rot. It is not necessary to remove any of the really rotted wood, but it is usually quicker and easier to remove 95% of the really crumbly stuff. In either case, whatever is left has to be reasonably dry. Once it is dry, you want to soak as much CPES into the damaged area as the wood will absorb. Let this cure for a day or two. Then start filling in the missing wood with Fill-It. When this cures you can sand to shape.

For the undamaged but peeling trim I would strip it all down to bare wood, and prime any cracks or gouges with CPES. Fill in any cracks/gouges with Fill-It. Sand if necessary, and prime everything with CPES.

Chronic peeling is almost always due to moisture getting into the wood. Around trim pieces, this is commonly due to water getting into cracks, and between the trim and what it is attached to, or wicking along nail and screw holes. If you are very careful when applying the CPES, you will be able to get it to flow easily into all these areas where moisture has been getting into the wood. Done properly, this should prevent the peeling problem. For cracks and other problem areas I will usually prime with CPES twice. So everywhere once, then cracks and nail holes, etc. again the next day.

Once you have eliminated the peeling problem you need to use a quality paint if you expect it to last 7-10 years. As long as the paint is not peeling, this is not a problem for a top quality paint. We sell a polyurethane paint that would easily last 10 years if it remains stuck to the surface. It is our Elasta-Tuff™ 6000-AL-HS. It is quite expensive, but very durable. It does have a strong solvent odor, so an organic fumes respirator with a N95 particulate prefilter added would be required for application.

There are some other quality paints that should be able to last this long as well. I would expect that any quality 100% epoxy or polyurethane would get the job done. A high quality oil based enamel would also likely last at least 7 years. Once we fix the peeling problem, it is really only a matter of applying enough coats of a quality paint that the sunlight will not be able to break the paint down in the time required. Polyurethanes and epoxies are the most durable. Oil based enamels are mid quality, and acrylics and latexes are probably the least durable. No matter what the type, stay away from really cheap paints. These are not going to last. The most expensive marine grade polyurethanes are $200-$250 per gallon, but believe me, they are worth every penny. These would be overkill in your application, but I would be looking for something in the $75-$100 per gallon range if you want the best quality.

Let me know if you have further questions.