Proper Wood Preparation for Your WOODguard Projects

Preparation for Initial Application of WOODguard

Both new and weathered wood should be cleaned prior to your WOODguard application. New wood may have mill glaze or planers crush; weathered wood may have collected contaminants from pollution or the beginnings of decay.

Cleaning Materials: Make a solution of 4 oz. of Oxalic Acid Crystals in 1 gallon of water; a stiff-bristled nylon brush; a garden pump sprayer; and power washing equipment set below 500 psi.

Procedure: Working in small, manageable sections from the bottom up, wet the wood with water, then generously apply Oxalic Acid solution using the garden pump sprayer. Keeping the surface wet, scrub the surface with a stiff-bristled nylon brush for 15 to 20 minutes. Do not let the solution dry on the wood. Then, power wash the Oxalic solution off the surface with clean water from the top down.

To avoid wood damage and achieve maximum effectiveness, make sure the pressure is set below 500 psi, and keep the nozzle of the power washer approximately one foot from the surface. A garden hose is not sufficient for this purpose, as it typically provides a maximum of 60 psi. Measure the pH of the rinse water at several places to make sure the water run-off is between 6.0 – 7.0 to assure that all of the oxalic acid is removed. If all of the oxalic acid is not removed the wood will develop a dark chocolate color. The pH strips from 6 to 9 are available at local drug stores, pool supply stores or discount stores. Let the surface dry for three days before applying WOODguard. When applying any chemical to wood on a vertical surface, ALWAYS apply from the bottom up to eliminate drip or run marks.

WOODguard Surface Prep

1 Pound Container

$25.00

Preparation for Re-Application of WOODguard

A second application of WOODguard will be required 2-4 years after the first application. South and west exposures may require treatment before north and east exposures. All surfaces to be re-treated need to be cleaned. Allow three good drying days before application. Do not use an iron bearing brush because iron stain could later develop.

Cleaning Materials: A solution of 4 oz. of 100% Tri-Sodium Phosphate (TSP ) or phosphate-free substitute, 1 qt. liquid bleach, and 3 qt. water; a stiff-bristled nylon brush; a garden pump sprayer; and power washing equipment set below 500 psi. Rust, Enzymatic or Tanate Stain Removal

If the wood shows signs of rust or enzymatic or Tanate staining, the Oxalic Acid treatment recommended for New Untreated Wood will remove these stains.

Remember: Wash from the bottom up. Rinse from the top down.
Apply when air and surface temperatures are between 50 and 95° F (10° to 30° C).
Do not apply when surface feels hot to the touch (over 95° F or 35° C) or when the surface is cool (below 50° F or 10° C). Perform color and batch checks before application (see instructions below). Do not apply when dew, frost, or other surface moisture is present. Apply product liberally in the direction of the grain, and completely saturate cut ends. Do not apply in wet weather or excessively humid conditions. A wet edge is not required throughout the process. Do not apply if the moisture content of the wood is over 18%. Apply one heavy coat. Do not apply more than one heavy coat. When applying any chemical to wood on a vertical surface, ALWAYS apply from the bottom up to eliminate drip or run marks.