How do you Determine.............

[walnutjerry]

what type finish is on an older piece of furniture?

A relative has an old dining table that has developed white spots at every place setting just from the heat of food on a plate. Even the spot where you would set a coffee cup has turned white.

Would the finish be varnish or lacquer?

I read an article a while back that addressed this issue but can't remember where I read it. If I remember correctly, denatured alcohol and 0000 steel wool would correct the blemish. Has anyone else faced this issue of white spots in the finish?

Any advice would be appreciated ---------I am going over there tomorrow armed with DA and 0000SW and give it a shot.

Thanks in advance. Jerry

 

[striker]

Hi Jerry,

Before you sand or do anything try some denatured alcohol on a out of the way spot. Shellac will turn white when in contact with moisture from a glass or cup. I recall reading how to remove white rings somewhere .........but old shellac will come back to life if you rub it out with a little denatured.

I'll look thru my matrial and post again if I come across anything.

Stephen

 

[Travis Porter]

I am in the same boat with the wife's dining room table. DNA first to see if it is shellac, maybe some Lacquer thinner in an inconspicuous place to see if it is lacquer, and from there, I don't know.......

If it is lacquer (which I think is the case in my scenario), I think I remember reading spraying some lacquer thinner to redissolve the finish.

Where is Howard?

 

[TracyP]

I remember reading a couple of months ago that if you use a household iron and cotton material that the white spots could be ironed out. I think it was on the ridgid tool forum. There were lots of posts that followed the original and everyone said that it worked. There were some instructions but I cannot remember what they were.

 

[wayne]

Can't comment on the shellac but the lacquers used on furniture was nitrocellulose lacquer and it would blush if a glass or anything else was sit on it because the finish was porus an the moisture absorbs into the finish.
Those of you that are old enough to remember the vehicles from the mid 50's and back they literally rusted before your eyes,the finish could be rubbed to a shine as long as there was some finish left on them but they would still rust through the finish because the finish was in the nitrocellulose family all the way down to the primers used on them. Even the high end lines of furniture being manufactured today still have nitrocellulose clears on them from the factory lots of the time.

Wayne

 

[GrumpyK]

If you want a thorough, comprehensive answer, go to the Library or a big Book Store and get a copy of "Understanding Wood Finishing, Revised Edition" (or even the original edition) by Bob Flexner. It has the major part of a chapter addressing this question, and this book is regarded as "the Bible" of wood fishing.

 

[GrumpyK]

OOps! That's "... wood finishing."