Carpentry and Woodworking - How to identify a wood finish

I recently purchased a table that is solid wood with an oak veneer finish. Is there any way to identify the type of finish that was used on the table (e.g., polyurethane, lacquer, varnish, other?)? Neither the furniture retailer or their distributor knows or can find out the type of finish that was used.

I am hoping to find a way to protect the existing finish or re-finish the top in the future since the table will get a lot of daily use and almost certainly will not retain it's current look. I don't want to cover the attractive top with a table cloth and using a glass top is problematic since the table has a butterfly leaf that will be used on a fairly regular basis.

Thanks for any input.

I assume this is a new piece. Polyurathane is the most commonly used. It wears better than shellac or lacquer. Shellac hasn't been used much in a long time. You might try a little test - lightly sand and coat with poly a spot on the upper back side of one of the legs and see how it does.

For the first time ever I have to disagree with Mark.

If this is a factory finish chances are 'way in favor of it being lacquer - either catalyzed or otherwise. It could be a conversion varnish, but that is less likely.

On the inside of a leg, rub the surface gently with lacquer thinner. If the rags starts to drag or stick, stop - the finish is lacquer. If not, it is probably a catalyzed varnish or polyurethane. In either case, a light sanding will allow applicaiton of polyurethane over the current finish.

George is the expert when it comes to furniture..... please don't beat me too hard:D:eek::D

Lacquer thinner will also disolve most paints but I assume it disolves lacquer real quick.

I understand that if the finish is catalyzed varnish or polyurethane, I am able to sand the finish lightly and apply polyurethane to protect the table.

What if it turns out to be lacquer? Is there any way to protect the lacquer finish? If not, is there a way to re-finish the lacquer finish after it's begun to show some "wear and tear."

Thanks again for your replies.

To add, if the finish is shellac, alcohol will dissolve it. Neither lacquer thinner or alcohol will dissolve poly.

If the finish is lacquer I would not use poly over it. Most paint stores sell a aerosole lacquer in various sheens.

Try this in the inside of a leg if your testing reveals the ifnish is lacquer. Not all aerosoles are compatible with factory finishes.

Mohawk sells an aerosole lacquer I use extensively. Their minimum order is $85.00 - you might fins a retailer in the area that sells their products.