Solid Hardwood, Engineered and Laminate Flooring - Wood Stairs

I have Fir wood stairs and would like to finish them with a clear polyurethane finish. The stairs had carpet on them at one time up the centre and are now discoloured. The centre of the stair is lighter than either side. Any suggestions on how to make the whole stair uniform in colour. We had to belt sand adhesive off of them, and now we have sanded the surface down with 150 and 220 grit. They are very smooth and look great except for the discolouration. Suggestions welcome! Thanks!

Unfortunately because the stairs were covered with the carpet the out side has aged with sunlight and wear. The only solution that you have is to stain the stairs to obtain a uniform color.
Or replace the treads.

Philly

Thank you for your reply regarding my discolouration problem. I have read that fir does not take stain well. What is your opinion on that? Also, will the stain cover evenly both the dark and light portions of the wood?

It will be next to impossible to get an EXACT color match across the treads. You need to realize that years of light have ambored the outsides of those treads. Do some samples. Go to the lumberyard and get a good size piece of fir and try some different stains on them. Look at it this way it gives the stairs character.

Philly