After fifteen years of putting it off, the time came for me to show my staircase some love. Not that it couldn’t cope without it: save the scratches and the finish having gone dull, the stairs, made of solid teak wood, have stood up quite well. The only visible marks were some urine stains, mementos from my cat’s first coming into season a couple of years ago.
Teak timber is quite dense and oily, and therefore resistant to stains, but poor maintenance gave the cat juice a chance to penetrate the wood surface enough to make any subsequent attempt at cleaning futile. Perpetrators of such transgressions deserve to be punished, but in this case, the perpetrator is immune to persecution.
The crime. 
The perpetrator.
I started off experimenting with two ways of removing the old layer of oil (it’s not really a layer, but anyway): a special teak cleaner, and white spirit. The application of the cleaner was a bit complicated for my taste: I had to wash the surface with water, spray on the cleaner, scrub with steel wool, wait for a couple of minutes, scrub again, rinse. White spirit was more straightforward: just scrub with steel wool, then wipe clean with a rag. So I stuck with it. The problem with both alternatives was that although they helped remove most of the oil (IMO the white spirit was more effective than the cleaner), they did not remove the stains completely. Both left traces that were visible from a short distance (30-40 cm). That was not good enough for me: The thought of the faded stains showing through would haunt me.
It was about time I did some real work: sanding. I started hoping that a little sanding with a fine sandpaper would do the trick and allow me to proceed with finishing, but I was wrong. 220 grit paper did not remove the stains. I had to go down to 80 grit and gradually work my way up to 220. Two hours and 15 stairs later, a layer of amber dust had covered everything around the staircase. But the stains were gone. I summoned what was left of my energy for a bit more sanding, with 320 grit paper. I could find few arguments why this was necessary, but I went on with it anyway, at my right arms distress.
Sanding in progress.
After a much needed break, time for my favourite part: finishing with teak oil. Teak oil, contrary to commonly held belief, is not oil extracted from teak wood, but a mixture of tung and linseed oil and some solvent. It is true that for this type structure finishing with polyurethane varnish might be more appropriate as it would offer more protection against friction and stains. Plus it would require less maintenance, if any. That said, teak oil, despite its weaknesses, it’s much better at bringing out the natural beauty of the wood, without exaggerating it. So, I went with it. I rubbed in the oil using a soft cotton rag. Three hours later, the oil had been absorbed and the surface was ready for a second coat. (For simple maintenance, no sanding would be needed; cleaning with white spirit and a single coat of oil would be sufficient.)
In teak oil we trust.
Ron Swanson is right: few things in life are as gratifying as finishing wood. There’s something magical about oil, wax or varnish getting spread on a wood surface; all of the sudden, the wood comes to life. Seeing the grain jump out of the dull sanded surface, and those sweet amber tones replacing the faded grey-brown of the unfinished wood is pure joy; the sore arm was a small price to pay for it.
