Glidden Brush Ups: Tannin Stains

What is Tannin Stains?

Brown/tan discoloration that typically occurs on woods such as redwood, cedar and mahogany.  May look something like this:

How do I fix it?

Investigate the source of the problem before preparation to ensure it won't spread. Wash or clean the surface well. Use an oil-based primer for severe staining.