We bought a house that is about 90 years old and has been privately owned for 25 years, however it was an ex council house. We are renovating it and would like to preserve the old wood on stairs and skirting board but want to get it back down to the bare wood. It is covered in a very thick varnish which nothing will touch. On top of this the old paint doesn't stick to it so its relatively easy to scrape these layers away leaving the thick varnish. I have tried Nitromorse (just wets its but doesn't remove it), have sanded it with the most coarse of sand paper on the sander and it takes days. Have even borrowed a carpenter friend's orbital sander which I expected to blitz it but it had about as much effect as my palm sander. Once we do get down to the bottom it is really lovely old wood, but it will take me the rest of my life to finish at this rate! Any advice please?