I have an oak table about 18 years old. It has gotten sticky in spots with a grayish film that just swirls around when you try to clean it. We use this table for all meals and yes, we have used a wash cloth after diner to clean it off. In the past a cleaning person used to use lemon oil on it. It made is shine but there was always a slight oil residue on it.
How can I clean it without knowing what the original finish was? A glass of water set on it will leave a white ring that disappears in a few hours.

Possibly a couple of things going on here. First, the white ring USUALLY appear if water vapor is penetrating the finish and being trapped beneath it. As you said it's going away within a couple of minutes, this means the vapor is escaping rather than trapping, leading me to believe that your finish may be somewhat thinned (physically rather than chemically), due in part to using a washcloth after dinner to clean it off. Problem here is, even though you're using a damp cloth, which would be pretty soft, over time it still has an abrasive action. As for the sticky spots, unseen I'd guess the following: a) the finish is wearing (as previously stated), and you're getting bits of the sloughed off finish, b) built-up dirt, etc. This happens with the use of lemon oil or almost any product if it's not permitted to either flash off or be polished off (in the case of a past wax), or c) a combination of a) and b). If the finish is softening, a solvent based product like lemon oil could contribute to dissolution of the finish. Photos would help a GREAT deal, plus Clough will probably be around... I'd like to hear his thoughts.

Bill

Hi, ceccarlson!

Thanks for mentioning me, Rover88! I appreciate that very much! :)

I agree with you Rover88 about the water vapor thing. I also agree with you that the finish is probably being eroded over time and that it's getting dirty.

Yes, if there's a finish, a finish that has become somewhat porous and also might be soft, that's where it's more likely for white rings to form if there's just a glass of cold liquid on it.

I don't know when this piece was built or the type of finish that's on it. If you scrape the finish with your fingernail or a knife, what comes off, please? Most likely it's some kind of clear finish that is coating the wood though.

When there's a clear finish that actually coats the wood, then a common mistake that people make is to use the oil type of cleaners and polishes on them. Those types of cleaners and polishes will really only work well on oil finishes. They can help for the wood to not dry out as quickly as it normally would.

For most types of clear finishes, it's best to use spray polishes that have as little wax in them as possible so that there's very little residue left on the finish. Residue is more likely to attract dust and dirt.

Yes, it would be helpful to be able to view some images, if that's possible.

It could be that your table might just need a rejuvenation type of finish applied to it to bring it back to usable, attractive shape. I'll be happy to describe how to rejuvenate a finish once more information is known here.

Thanks!