Wood Stain not penetrating

[MookoTheKing]

I just had a new set of stairs built and put in by my contractor and now I'm staining it myself. The treads are unfinished red oak, so i sanded it, applied pre-stain conditioner and when I went to apply the Minwax dark walnut oil based stain, there was one spot on the treads where the stain just would not penetrate. The rest of that particular tread took the stain fine but just that one spot where it didn't and still has that unfinished wood look. What would cause that and how do I get it that spot to absorb the stain? Do I need to re-sand that spot and clean it with something?

[wtnhighlander]

That spot looks very much like it was 'pre-finished' by accident. As if a bit of clear finish, or even that conditioner stuff, was spilled there and allowed to dry. I suspect the only way to get it even it sand it all back to bare wood.

If you are artistic, you might try using some gel stain of the same color to 'paint' that area with background and grain. Gel stain mostly dries on the surface, rather than penetrating. Don't try to just apply gel over the whole tread, though. It will all get darker, but the lighter spot will still be lighter.

[drzaius]

Something was definitely spilled on there prior to the stain. Silicone compounds are the devil for repelling finishes.

The best result will be had by sanding the entire tread back to bare wood. Before reapplying the stain, test that spot to see if it will take the stain. If not, more sanding.

Oak, red an white, takes stain better than most any other wood. Using a conditioner is unnecessary & I think can cause issues itself.

[MookoTheKing]

I sanded it down with 80 grit and reapplied the stain successfully.  I also noticed some uneven staining on some other treads as well and I think it might be due to uneven sanding due to dull sandpaper.  I was using 120 grit but as I kept sanding the sandpaper got dull and that 120 grit ended up being like a 300 grit and those parts looked much lighter.  Lesson learned.

[Chet]

54 minutes ago, MookoTheKing said:

I was using 120 grit but as I kept sanding the sandpaper got dull and that 120 grit ended up being like a 300 grit and those parts looked much lighter.  Lesson learned.

Yea, sand paper isn't the place to cut cost on any project.  Change you paper the minute it quits working for you.

[Mark J]

8 hours ago, MookoTheKing said:

the sandpaper got dull and that 120 grit ended up being like a 300 grit

That's a common misconception. When sandpaper get's dull it doesn't behave as if it's now a higher grit, it just behaves as if it's dull.  So it's not really doing anything or at least anything much.

Knowing when to toss a piece of sandpaper is something I think everyone struggles with, but I try to keep one instructors admonition in mind:  "The sandpaper is not precious".

And then of course there's the lyrics to the sandpaper song:

You got to know when to fold it,  Then how to hold it, Know when to toss away, Or it won't be fun.

 (appologies to Don Schiltz).