I'm renovating an 85-year-old home. The flooring downstairs is white oak; upstairs is old-growth southern pine.

The finish on all of the floors was shellac. As near as I could tell, it was the original finish, and was in remarkably good shape. The floors, too, were good, both structurally and cosmetically. I sanded everything with one of the rental orbital sanders, removing pretty much only the finish. I'm in the process of cleaning them with denatured alcohol to try to get the last of the shellac off.

I was planning to use a polyurethane finish (specifically UGF's ZAR Ultra), but am advised by UGF's technical department that shellac MUST be removed with a chemical stripper prior to using their product, due to the natural wax in shellac.

So, my questions are:
1. Would a cleaning with denatured alcohol constitute "chemical stripping," or would this still leave waxy residue?
2. If I were to seal the remaining existing finish with something like Zinnser's Bulls Eye (which is a dewaxed shellac product), would it raise the grain of the wood such that I would need to do another sanding?
3. What other reasonable options exist for a floor finish that won't require constant renewal?
4. Am I agonizing needlessly?

Perhaps you need to call UGF's technical people again and find out about the alcohol. I am a little concern that alcohol doesn't cut wax that well. Mineral sprits might be better on most waxes. Perhaps you need to follow one with another.

There is a much tougher floor finish available, a moisture cure urethane. It dries by absorbing moisture from the air and actually chemically bonds with the wood itself. I applied it to may hardwood floor in 1998, and it is still is looking good despite all the abuse of a Lab or Shepherd spending it first year on it every year since, plus visits from their friends and family. Unfortunately, the only finish I am able to find it in is an ultra high gloss from Sherwin Williams, Rexthane. It is a single package and goes on just like anything else except you do need very good ventilation. The thinners in it are very strong. It is an industrial product meant for sealing concrete floors. It says on the package ''Not for residential use''. Well I used it on my family room floor anyhow, and it worked great. I also used similar products on wooden toys I made for my kids. It survived them, some of their cousins, and soon will be subjected to my grandson.

Labman,
Thanks for the quick response. I saw your reference to Rexthane in one of your previous posts when I was searching the forum. I guess I should have posted that I'm looking for a satin finish.

I agree that mineral spirits is superior for cutting wax. If it were an after-applied wax that's what I would have used. As it is, the wax is inherent in shellac, thus the alcohol, which is the solvent for shellac

I got nowhere in 1998 finding a satin finish. I just put "moisture cure urethane" + satin into a search engine and have 85 hits. With a little digging, you might find something.