Finishing Polyurethane Rail, Best Paint for Porch Railings

All Polyurethane products from American Porch are shipped with 2 coats of paint. The second coat is an exterior product that acts as a primer for field finishing.  Polyurethane products require finishing to complete the installation procedure and be fully covered under warranty. This procedure includes all steps necessary to repair any seams/joints in molding installation as well as filling the screw/nail holes made during the installation.

The steps to be followed are the same for all polyurethane products and are as follows:

  1. Allow adhesive to dry 24-48 hours before beginning the finishing procedure.
  2. Cut off any excess adhesive using a utility knife.
  3. Clean and remove all dirt, oil and greases from the surface of the product using a wax and grease remover product such as Sherwin-Williams Pro-Clean Professional.
  4. With 80 grit sandpaper, “rough up” the surface surrounding screw/nail holes made during installation. This will ensure good filler adhesion.
  5. Sand all joint areas with 80 grit sandpaper to rough up and blend in any misalignment of the product during installation.
  6. Once all the areas needing repair are roughed up and blended in, remove all dust from the surface of the product, again using the wax and grease remover. Compressed air can be used to remove the excess sanding dust.
  7. Apply filler to the areas needing repair. (Use a 2- component, light weight automotive filler, such as Car Systems AutoFit, Eurosoft # CARS134458) Apply the filler using thin coats, sanding between each coat with 120 or 180 grit sandpaper. Doing so will reduce the amount of material which will have to be sanded away. Generally it will be necessary to apply 2 or more coats of filler to get the desired results.
  8. Prime all areas, which have had filler, applied. (Use an interior/exterior latex primer such as Sherwin-Williams A100).
  9. Caulk seams along bedding edges of molding, around ceiling medallions, around column shafts, around caps/bases, around the end of railings, around balusters, and in any other area necessary to provide a clean installation. (Use an exterior, paintable exterior Latex caulking such as Sherwin-Williams ProSelect 1100A).
  10. Paint the product as desired. Do not use dark or glossy colors as they will accentuate any flaws left during the installation. (Use a product such as Sherwin Williams Interior/Exterior A100 or SuperPaint, flat or satin).
    • Primer: Sherwin Williams A100 or PrepRite Classic Interior Latex Primer
    • Paint: Sherwin Williams A100 or SuperPaint
    • PreCleaner: Sherwin Williams Pro Clean Professional
    • Caulking: Sherwin Williams ProSelect 1100A
    • Deco Flex: Sherwin Williams SuperPaint