Staircase stained or painted?

I am currently renovating our inherited house (built in 1965). Now we have reached the staircase and wanted to sand it down and repaint it. But easier said than done. After trying it with 120 and 80 grit sandpaper, partial success was seen on the stair side and the tread surface. However, sanding under the tread had no effect. It still shines. Then we were advised at the hardware store to try using paint stripper. They said the paint would just peel off like that. Said and done, let it act for several hours. Nothing happened. Except a few spots where some came off.
Now a colleague who saw the staircase in the picture said the stairs were not painted but stained.
We have no idea how to proceed. Can anyone give a tip??
After removing the carpet, the exact position of the carpet can be seen in the wood due to different brightness. Can that be removed too?
We actually wanted to paint the staircase dark (towards walnut).

Hi,

I can't really imagine that, you have to see whether it is painted or stained!

If the grain is clearly visible then it is stain, and if you don't see it and it is a uniform surface then it is painted.

All clear?

Beagle

Hello,

so if you would post a picture then we could certainly tell you more. Just in your head like this is not so easy!

Fischer

Hi,

I can't quite imagine that, you have to see whether it is painted or stained!

If the grain is clearly visible then it is stain, and if you can't see it and it is a uniform surface then it is painted.

All clear?

Beagle

Before you make such statements here you should first find out what staining and painting are. When staining, the original wood is given a different color. The stained wood is then always sealed either with matt varnish or lacquer. Additionally, with clear lacquer of course you can see the wood grain. Now to the actual topic. A remote diagnosis is naturally difficult but I think that the staircase (stringers, railing) was only painted thinly once or twice. The steps were always painted a bit thicker and more often because they are highly stressed. If you have about a 2mm thick or even thicker layer of lacquer on there, it will just take a bit longer to sand off. I also remember that there used to be a special two-component lacquer for stair steps. It became incredibly hard. If you have that on there, good luck with sanding. Since you want to change the entire color scheme of the staircase, you have to sand down the whole staircase. On the smooth surfaces that might still be feasible, but on the railing and handrail I already see difficulties in completely sanding off the lacquer. If you also have turned spindles in the railing, I can only advise you to have them very slightly re-turned at the joiner’s. You will never get them completely cleanly sanded. Because any spot where there is still lacquer will show up as light spots when staining or glazing. I would attack the steps again with 40 grit sandpaper and a delta sander. When the lacquer is off, sand further with 100 grit using an orbital sander. Then continue treatment as you wish.

Best regards, Thommi