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General Preparation for Siding
General Preparation for Siding

For optimum long-term visual appeal of your natural wood, correct wood surface preparation is of great importance and well worth the effort.

Surface must be free of all dirt, mildew, foreign matter and loose wood fibers. Regardless of how clean the wood may appear, immediately prior to coating begin by aggressively brushing the surface with a stiff synthetic brush to remove loose wood fiber.

To ensure NatureColor® or NatureOne® is allowed to penetrate and anchor itself to the wood surface by following these instructions:


1) New or Weathered Rough- Sawn Wood Siding:

Cleaning Solution
Mix and put in a garden sprayer.
– 4 oz TSP
– 1 quart of liquid bleach
– 3 quarts of warm water

Mix enough cleaning solution in batches to cover the area to be coated (approx. 150 sq ft per gal).

  1. For wanted vegetation – wet with clean water and cover with plastic tarps.
  2. Cover windows and door openings.
  3. Wet surface with clean water.
  4. Apply cleaning solution from the
    bottom to the top.
  5. Keep surface wet with cleaning solution for approximately 15-20 minutes.
  6. While surface is still wet, power rinse with clean water. Rinsing the surface from the top to the bottom. WARNING! Do not exceed 500 PSI on the surface of the wood. Excessive power rinsing of the wood may cause damage that will affect the performance and appearance of the wood finish. Use a 45 ̊ fan tip keeping the tip approximately 12” from the surface. Avoid “fuzzing” the outer layer of the wood, which indicates that the power washing is too aggressive. The objective is to remove dirt loosened by the cleaning solution and loose wood fiber. Tip: The use of a garden hose (approx. 60 PSI) does not deliver enough pressure for effective cleaning.
  7. Allow three good drying days before coating. Moisture content should be no more than 18%.

2) New Smooth Wood Siding:

Smoothly planed surfaces should be assumed to have a milling glaze that will prevent the proper adhesion of NatureColor® Base Coat or NatureOne®. Use one of the following methods:

Method A
Sand the surface with 60 to 80 – grit sandpaper and remove the resulting dust with a vacuum.

Method B
Use an approved “Mill Glaze” removing product following product label instructions. Please note that experience has shown us that physical abrasion of the surface with a stiff synthetic brush improves the effective removal of the “Mill Glaze”.

Method C
Follow the preparation instructions for new or weathered rough wood.


3) Previously Coated Wood:

NatureColor® Base Coat, Recoater or NatureOne® are suitable for structurally sound, previously uncoated weathered wood or wood surfaces coated with other finishes, provided such surfaces are thoroughly reconditioned. If the surface has evidence of wood cell deterioration or coating failure, then complete removal of the existing deteriorated wood cell structure at the surface and any previous finish remaining on it, is a mandatory prerequisite for applying NatureColor® Base Coat, Recoater or NatureOne®. Please contact us for further assistance.

If coating removal is necessary, use one of following methods:

Method I
1. Using 60-80 grit sandpaper, sand the surface down to bare wood. Always sand in the direction of the wood grain.

2. Vacuum all sanding dust from the surface.

Method II
1. Chemically strip the wood with a wax-free chemical stripper.

2. Following label instructions, to strip down to bare wood.

3. Let the surface dry for three (3) good drying days before coating the wood. Moisture content should be no more than 18%.

Color Check

Always do a complete system color test on a sample of surface that will be used in the project from the NatureColor® or NatureOne® purchased for the project.

Batch Check

Batch numbers appear on the Gallon and Five Gallon containers. For color consistency always use the same batch number for the job. If different batch numbers exist, mix all batches together to assure color consistency.


NatureColor® Base Coat and Recoater perform best applied with a longhaired natural bristle brush. NatureOne® acrylic exterior is best applied with a nylon-polyester brush. NatureColor® and NatureOne® products can be sprayed, but always back brushed to work the product into the wood surface and to even the pigmentation and film thickness.

See specific substrate application guides for spray settings.

Back Priming

For our products, application of the first coat to all sides of the boards is recommended to control the intake of excessive moisture in the wood, which may result in coating failure.


Vertical surfaces should be coated within two weeks of cleaning procedure, second coat within two weeks of the first coat and third coat within two weeks of the second coat.

Horizontal surfaces should be coated within one week of surface preparation.

If subsequent coats are extended beyond these parameters cleaning of the surface should be done per the maintenance preparation specifications.


TSP, bleach and water solution may affect grass and vegetation if applied directly. Prior to applying the cleaning solution mist the vegetation with water and cover with plastic tarps.


The information and suggestions for use made herein are based on research and experience of Structures Wood Care, Inc., and are believed to be reliable. Application and surface conditions are beyond Structures Wood Care, Inc.’s control. Liability, if any, is limited to replacement of product or refund of its purchase price at Structures Wood Care’s option. Proof of purchase is required. Labor or cost of labor is excluded. Buyers must determine for themselves, by preliminary tests or otherwise, the suitability of the products for their purposes.