Use denatured alcohol soaked in an a clean rag or wiping cloth to remove grime that have accumulated over a period of.
How to wood grain a garage door.
Brush marks going in different directions will show through the grain and lessen the effect.
Beginning with the door panels apply a thin coat of gel stain to an entire door panel using a clean lint free cloth.
Start by using a brush on all the recessed areas and then use a roller on the flat surfaces.
Lightly sand the door surface with a fine sandpaper for better paint adhesion.
As much as possible try to imitate the natural texture and grain direction of real wood.
A fine wood graining finish requires that you apply the graining base by brushing in the direction of the grain.
Allow 24 to 48 hours for the stain to dry completely.
Having properly prepared the surface you are now ready to apply old masters graining base.