I'm having my staircase treads and banister refinished. Staircase treads are red oak and I think the banister is the same. Started with a mahogany stain. Changing to a very dark, black stain. Part of a large remodel but this part is causing the most problems. Original subcontractor came in and sanded just the middle of the treads - the easy part - and some of banister, then just used a scraper on the rest, eg, edges of treads. Then he came in and tried several stains to see which one we liked. We picked one and they put it one one of the treads. Unfortunately it just wouldn't dry completely even after several days. So they tried something else. This dried but the stain seemed to come off easily, e.g., painters tape applied to treads to paint the risers lifted some of the stain off. Exit subcontractor 1, enter subcontractor 2. At this point the stair treads have a single coat of dark stain - no poly, varnish etc. So the new contractor cleans the treads up but doesn't re-sand. Then he wipes them down with what looks like a piece of screen. Then he applies a combo stain and varnish or polyurethane on one tread so we can see what it looks like. Looks pretty good except for one patch right in the middle of the first tread that seems darker, heavier, glossier. In other words it noticeably stands out. Says he can fix that. Goes on and applies the stain/varnish mixture is to all the treads. Looks pretty good until you get close and then you can see several places where you can see through the stain to what looks like wood. Says it just needs another coat so he applies two more coats and this problem of seeing through to the wood actually gets worse not better. If you stand back and look at the stairs they look fine but if you look closely you can see right through the finish. What do you think is going on here and how can we fix it? Appreciate any help.

Biggest problem is most people dont understand how to get a dark stain. They always sand it smooth and boom the grain is so tight no pigment will penetrate into the wood fiber. That penetration is necessary for a proper bond. By applying more stain over a already stained floor it will make it a little darker but you still have to wipe off the excess or it will never dry and will have bonding issues if you do get it to dry. to have a piece of wood take a dark stain it has to be prepped correctly by sanding to no higher than 100g and then a 50/50 mixture of water and denatured alcohol should be wiped on the newly sanded wood and left to dry overnight. This process will open the grain back up and allow the heavy pigment to be absorbed by the wood. You will have to be very careful and not use the steps while they are drying and before they are stained. Once you have the stain down you can clear coat it to finish. The "poly shading" your guy has done will look ok but as it wears so does the color so your traffic patterns will become pretty obvious over time.

I'm thinking your not using pro floor refinishers, if they are using a combo. As Kevin says first you stain then use a poly.

Thanks very much for the posts. Can you recommend the best way to fix this. Do we have to start over with sanding and following your recommended procedure? Can or should the finish be taken off by using a stripper instead of sanding?

if you want it to be right it needs to go back down to bare wood and best way to do that is to re-sand. Staining oak black isnt for a half baked floor guy. He needs to understand what he is doing, if you have to explain this to him then your backing up, find someone who knows how to do it without an internet forum education would be my best recommendation.

Excellent advice. Thanks. Wish you were in my area.

Kevin, is half baked worse or better than fully baked?

Good question!

First, the treads won't take the stain the same unless they are sanded with the same grit.

Stains penetrate the cells(the cells absorb the stain).
Not enough sanding to open the cells and the stain will just sit there because of too much surface tension.

Stain is applied and when wiped off. the wiping off absorbs most all the wet stain.

If the stain peels, they put on too thick and let it dry without wiping down.
Or the surface was burnished.