Cleaning up coffee table, not sure if I removed old finish

[Michael Jasper]

So I have a coffee table (commercial furniture) that is 15+ years old. Probably a polyurethane finish. I've noticed a gummy coating mostly on the side of the table where we often put our food, so I figured over time, dirt, grease had built up. I tried cleaning with Murphy's oil soap, which did nothing, so I started using a plastic scraper to kind of "push" off the coating. After doing a bunch of this, I started to think it was the finish rather than grime I was peeling off. (See photos).

Tried to reason this through...since the gumminess is entirely on the side of the table close to where we sit and put plates, it makes sense that it's not the finish failing - otherwise, I'd expect it to be happening all over the table. Also not clear to me if whatever the finish is (let's say poly) would over time get soft and kind of sticky.

The middle photo - 15223 - shows what it looked like *before* I started scraping it.

Question is where to from here.

To make it more complicated, the piece is large and heavy - no way I can get it down to my shop. I'd prefer not to try to strip it or refinish it with anything toxic as it's very close to the kitchen.

Any thoughts would be appreciated.

Thanks,
MichaelIMG_20200513_115926.jpgIMG_20200513_115936.jpgIMG_20200513_115223.jpgIMG_20200513_115139.jpgIMG_20200513_115134.jpg

[Paul F Franklin]

My first step when trying to rejuvenate or restore older furniture is to wipe it down with mineral spirits. It will remove wax and grease and grime without damaging most finishes. So I'd try that in a little area. That may help figure out what is going on. Next step would be a test with denatured alcohol.

[John TenEyck]

Most commercial furniture is finished with lacquer. The damage to the finish on your table is consistent with what various hot and cold foods and liquids will do to lacquer and several other uncatalyzed finishes over the years. It gets sticky and gummy and is pretty easily scrapped off with your fingernail, etc.

If just that one board is in poor shape you should be able to strip off the finish on just that board by masking off the rest. Be sure to put paper and plastic on the floor underneath, too. If the finish is uncatalyzed lacquer it will come off with lacquer thinner on a soft cloth. Open the window, don't smoke, and wear an organics respirator while you use the stuff. 3M's Safest Stripper should remove it, too. Once the finish is off you can reapply new finish either with rattle can lacquer or brushing lacquer, using the same precautions. Use whatever sheen you think best matches the original.

John

[Michael Jasper]

Thanks for the input both.
Applying lacquer in the primary living and eating area seems less than ideal, even with all the windows open - esp with us all quarantined. Maybe later when we're able to leave for a day.
Would it be crazy to apply water-based poly to that one board? I have some General Finishes product. I'm guessing it will look very different. Just trying to think of something less toxic than lacquer. I used some rattle can lacquer recently on a couple small boxes that i was able to spray outside. Pretty strong stuff.
I suppose brush on might be better for limiting the fumes?

[Richard Coers]

Commercial manufacturers have never used polyurethane. Dries too slowly. Even at 15 years ago, it could be conversion varnish, or as mentioned, lacquer. I would never use lacquer on a table, even for refinishing. It's not tough enough for food and drink. If that table had a gummy finish from food and hand oils, it must be stripped. Nothing will stick to it as a new film finish.

[Michael Jasper]

Thanks Richard - so what would you suggest for a new finish for top? I know water-based poly is not as liquid resistant as oil-based, but I'd feel more comfortable using it in a living area.

[Jamie Buxton]

.. I know water-based poly is not as liquid resistant as oil-based...

Not really. Fluid resistance is mostly a matter of how thick the finish film is. More coats gives more resistance. The one exception is that waterborne is generally more sensitive than oil-based to alkalines like Windex and ammonia, but if you don't clean your table with Windex you'll be fine.
The bigger difference between waterborne and solvent-borne finishes is color. Waterbornes are generally water-clear, and solvent-borne have some amber color. If you want to use waterborne for odor reasons, do a test panel to see if the color is okay.

[Michael Jasper]

Thanks Jamie - much appreciated.