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We have a second-hand table with a mysterious finish.

The wood underneath is pale, possibly pine. With the finish, it's a slightly darker and "warmer" colour. The table is not antique; I'd guess only about 20 years old.

The finish is soft, so you can easily score lines in it with a fingernail. It feels slightly sticky if you just press it with a finger. It becomes VERY sticky if it gets wet, and will permanently stick to any paper left on it, so the paper can only be removed by painstakingly scrubbing it into shreds. It also turns white after getting wet, for an hour or so, then fades back to brown.

Because of the stickiness it attracts dirt horribly, and is covered in dark grime which is very hard to remove. The grime can be removed by lengthy scrubbing with a rough sponge and Flash kitchen spray, but then the finish partly comes off too.

We tried Nitromors paint and varnish remover, followed by white spirit. It made some progress at removing the finish, but left it patchy and smeary and not completely removed; I think we've had better results with Flash kitchen spray.

Can you help me identify the finish, and recommend a way to remove it properly?

  • 1
    Badly applied or poor quality shellac? It's origin is bug extracted tree resin dissolved in alcohol. It's drying properties are dependent on the quality and type of tree the insects were extracting sap from. – Fiasco Labs Nov 20 '12 at 15:20
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By "White spirit", do you mean turpentine or mineral spirits? If that had no effect on it... My best guess would be that it's improperly cured polyurethane, or water-based polyurethane that wasn't mixed properly. Additionally, polyurethane doesn't take to pine well and is pretty resistant to being removed chemically, so there's another pointer in that direction.

You can try denatured alcohol. If it comes up with denatured alcohol, it's probably improperly mixed shellac.

What I'd probably do if I were you would be to sand it down completely back to bare wood, first with 80 grit and then 120 and 220 grits. I know it's a pain in the butt, but it'll provide the best finish overall. Then stain it and finish it again with something that isn't polyurethane... if you stain it, I'd recommend a lacquer finish like Deft, and then a really nice set of absorbent coasters so that you don't keep getting the surface wet. ;) Or if you do use polyurethane, use a satin spray in a rattlecan and bring it indoors to a moisture and temperature controlled environment to cure for 48 hours before you put it back into use. And your last option would be to paint it (after sanding back to bare wood, or it won't adhere!) with an oil-based enamel and a bit of penetrol.

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    en.wikipedia.org/wiki/White_spirit - mineral spirits. I think if we sanded it it'd just make the sandpaper all gummy and sticky. That's what happens if we scrub it with a rough scourer, I was thinking we'd need to remove the finish, or most of it, before sanding. – Rachael Jan 9 '12 at 7:24
  • As for what to re-finish it with afterwards, I think that's beyond the scope of the question, but personally I'd like to finish it with something very hard and smooth and impermeable, that wipes clean as easily as plastic. We already use coasters, but sometimes spills happen (we have a toddler). – Rachael Jan 9 '12 at 9:23
  • It sounds a lot like shellac to me. +1 to the denatured alcohol. – JoeFish Jan 9 '12 at 14:44
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    It would gum up the sandpaper to start with, but eventually you'd get through it. If you really, really want to use a chemical stripper, you can try the stronger SuperStrip -- the "wood, metal, auto, masonry, and marine" one. That stuff will take off just about anything, but is a pain to clean up... make sure you get something that you can seal up the remains in, like a metal paint can, and you'll need to take it to a hazardous waste collection place. And make sure that the gloves you get specifically say they're resistant to tolulene. – Karl Katzke Jan 9 '12 at 16:52
  • OK, I got some denatured alcohol / methylated spirits today, and it had no effect at all. The guy in the hardware store where I bought it also thought it sounded like a water-based finish, and that the only option would be to sand it. I was hoping if it's water-based it would be easier to remove, not harder; but I guess not. – Rachael Jan 10 '12 at 18:18
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I'ld be scraping it off with a paint scraper:
One of these ones:
Paint scraper

Then sanding it down once the bulk was gone, (save gumming up a ton of sand paper)

  • Furniture scrapers would be more controlled.... I'm starting to become very fond of mine. – keshlam Sep 16 '16 at 3:42
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For the record, I've had some success with sodium carbonate solution, which we happened to have in the cleaning cupboard. It hasn't worked everywhere, but where it has worked it was very low effort: apply the solution with a cloth, leave, wipe off. Ended up with bare patches of wood, and an opaque yellowish solution.

1

I do a good bit of furniture refinishing in my shop - altho I am a sign painter by trade ... I've seen all sorts of things come thru,my shop!

Here is one of the best ways to remove the gummy gunk - before you waste a bunch of sandpaper ... put all that sanding energy into steel wool and Comet or Ajax.

Use the medium coarse steel wool - finer will work too - but the coarser cuts the muck better.

Keep a bowl of water handy, and a few clean damp rags.

Work one section at a time.

You are not going to get the table soaking wet.

make a paste with the water & comet about the consistency of pudding. Scrub scrub scrub with a piece of the steel wool. It will be visibly loaded with the gunk you're removing!

Rinse it iout in the bowl - and go again - repeating these steps as often as needed. When the steel wool starts looking ragged or your tired of rinsing it - get a fresh piece.

The clean ramp rags are for keeping any standing moisture wiped up as well as duty water.

When your table is clean - let it sit a couple of hours and get completely dry.

Now you can sand it down nice & smooth without working your sander to death and swirling a bunch gunk around with clogged up sandpaper.

I have cleaned and refinished cabinet doors and table tops this way many times.

Good luck!

1

Most surfaces will be either lacquer or polyurethane varnish of some sort. Furniture companies have always been known to cut corners and shave cost. If lacquer becomes sticky over the course of a few decades it can be reamalgamated with fresh lacquer, which will postpone the need for complete restoration for a period of two or three years. However, if polyurethane varnish becomes sticky then there is no other acceptable recourse other than to remove the finish and start again.

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After attempting every known thing at the time, I was faced with removing a thick layer of sticky varnish like finish from my doors,(thick & dark), wanting to restore them to natural pine. Good old 'Sugar Soap' was the only thing to remove it, then a wash down. Brilliant finish to take new sealant too!

When restoring antique furniture, I often used a Brillo Pad, soaked in meths to remove the old finish, before attempting new finishes or polish.

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I'm dealing with the same issue on my kitchen table. The best thing I've found to be the option for good results is 91% alcohol (Walmart brand) and a scraper. I've poured it on, let it sit then scrape. I really don't think I'm going to need to do too much sanding before coating it again with some type of sealant.

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Nobody mentions cleaning with TSP (Trisodium phosphate) I have a project like this coming up next week, and without seeing it I will be bringing alcohol, Lacquer thinner, and tsp along with some soft brushes and soft towels. and spraying with a spray can of clear coat.

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The existing finish (shellac, linseed oil etc) may be affected by your cleaning solution. Consider using Acrylic finishes, as they, being water based, are less likely to be affected by spirit based cleaning products...

protected by Community Aug 4 '18 at 18:55

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