Furniture, Wood and Cabinetry Finishing - Refurbish Oak Stairs

Hi,

My oak stairs have white and black stains from years of water and ice penetration. I am in the process of refurbish my oak stairs by using stain remover.

Questions:
-How do I remove all those white and black stains?
-Can I use regular wood filler by Lepage to fill the holes where the nails are?
-What kind of finish do you recommend that will be durable but still maintain that clear finish look?

Hope to year from you,
Helma

Stains that have penetrated into wood can often not be sanded out. Some have some success lightening them with wood bleach and then staining wood a darker color to disguise them. A non-shrinking wood filler can be used to fill holes Two or three coats of polyurethane can be used as a surface finish.