Wood Door Finishing Guidelines & Instructions

Wood Door Finishing Guidelines & Instructions 

IMPORTANT: Unfinished wood (primed or raw wood) parts should never be left exposed to the natural elements. All six sides (front, back, top, bottom, and left, right) of each section must be finished using one, or a combination, of the coatings recommended below. It’s very important that the inside surface and edges are finished to prevent moisture penetration through the door. 

Surface Preparation: Surfaces must be clean, free of dirt, grease, dust, or any substance/material that will prevent paint adhesion. When painting a door, the finish coat must be compatible with the primer or base coat. Scarring that occurs during the shipping, handling and installation process must be re-sanded and to be free from defect. All surfaces should be sanded with 220 grit or greater sandpaper going with the grain only. 

Paint Grade Finishing Instructions: A latex base coat or primer is typically recommended for use with an acrylic latex finish coat. Alkyd or oil based primers are typically suitable for both latex and oil based finish paints. Always follow the paint manufacturer’s application and refinishing instructions. A minimum of one (1) coat of primer paint and two (2) coats of exterior grade finish paint should be applied to all surfaces of wood parts. Always follow the manufacturer’s instructions for application and re-coating. 

Stain Grade Finishing Instructions: Typical stain systems include a stain coat, sealant coat for moisture and UV protection, and a top coat for abrasion, scratch/mar and weathering protection. Some stain systems will combine several or all of these steps. When staining a door or using a stain type finish coat always select a high quality product that is recommended for exterior application on the type of material or wood species used on the door. Stains and stain finish systems vary widely in their recommended application and re-coat methods as well as intervals between re-coat or refinish. Always follow the manufacturer’s instructions for application and re-coating. Recommended product: Sikkens® brand Cetol 1® and Cetol 23® plus finishing system 

“Tannin” content: Some woods such as Western Red Cedar and Redwood have higher tannin content, which is one of the properties making them resistant to rot and decay. This high tannin content can also cause “tannin bleed”. This is evident by a brownish coloration bleeding through the primer coat. When this occurs, a stain blocking type primer or intermediate coat must be used on the affected areas. If not treated, these areas will typically bleed through the finish coat of paint. Tannin Stain Blocking primers have high levels of components capable of locking the stain as it dries. Roughly 95% of tannins will be blocked from transferring to the next one with an average of a 5% bleed through. Currently, a 95% block is the maximum one can expect. Another characteristic of TSB primers is a decreased resistance to abrasion, particularly for products shipped without top coats. The best process is to apply the TSB primer and allow for it to cure, followed by a second coat of standard primer to hide stains and resist abrasion. Dark colors. Dark colors are not recommended especially when the door has a direct southern exposure. 

Dark colors cause excessively high temperatures to develop on the door surface and coating which can lead to shrinking and cracking of the wood surface and rapid deterioration of the finish. Products placed under these circumstances will be void of warranty. 

Weather Exposure: Environments must be considered during the door selection process. Shrinking, swelling, bowing, warping and cracking are not considered defects as they are a natural uncontrollable characteristic of natural wood. 

Caulking: All joints and horizontal areas should be caulked with an exterior grade caulk prior to finish painting. In particular, many wood doors have a panel that sits in a slot on the rails. This slot is designed to be larger than the panel width to allow for expansion of the panel. Care should be taken to caulk these slots with a flexible exterior caulk after priming but before the finish coat is applied. On Stain Grade doors any necessary caulking should be completed after the door is finished. Recommended product: Lexel® clear caulking Finish coat: 

Wood variations: Wood has a lot of natural variety, which may result in variations of color. If a uniform color is desired, care should be taken to achieve a uniform stain application. Wood doors intending to be stained should be specified as “stain grade”. “Paint grade” wood doors may be made of materials that cannot be stained. 


Holes in door: When required, nail, staple or screw holes should be filled with exterior grade wood filler, sanded and finished along with the rest of the door. Optimize Garage Doors does not putty the following types/species of lumber; Marine Plywood. Optimize Garage Doors does not hold any responsibility of color matching putty for the following species of lumber; Cedar (all species of Cedar) or Redwood nor or they responsible for any color variation of the putty once a stain and sealer are applied. 


Warehousing or storing: When warehousing or storing unfinished wood garage doors prior to installation, caution should be taken to protect the wood parts from direct exposure to moisture conditions or other extreme environmental elements. Please note that moisture conditions can vary greatly, affected by geographical factors such as high humidity, rain, snow. Also, poured concrete, plaster and taped drywall are sources of moisture within a garage space and can be detrimental to an unfinished wood garage door during warehousing or storing. Moisture is typically evident by condensation on windows, floors, or metal fixtures within the garage. If it feels damp, provide ventilation. Always consult the garage door manufacturer’s warranty terms for guidelines on warehousing or storage. 


Yearly inspection of all surfaces of each door will reveal the extent of weathering and need for refinishing. Your specific climate may demand a yearly refinishing process. Your annual inspection will ensure the longevity of your Optimized Garage Door.