Dilemma - rubbing alcohol applied to dining room table

peter george

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Attempted to clean a mid-century dining room table by applying rubbing alcohol. Yes, I know now this was a really bad decision. Table is now cloudy. Applied spray wax, then Old English oil, then another coat of wax. This helped only for a short time. By next morning the cloudiness had reappeared. Sick about it. Cynthia White suggested posting a thread on the FamilyWoodWorking forum to see if anyone has had an experience with something like this and knows what now should be done. Thank you in advance, PG
 
Welcome aboard, Peter. Glad you found us. I'm no expert, but if the finish on that piece was shellac based, alcohol is a solvent and maybe that's why it clouded up. There are a few finishing gurus that post here and I'm sure they will chime in when they get a chance.
 
I bet the problem is that the finish was shellac, which is crystals produced by the lac bug dissolved in alcohol. When applied, the alcohol evaporates and leaves the ... shelLAC. When a second coat is applied the alcohol partially dissolves the first coat, making the coats blend together, called burn in. A typical finish is many thin coats applied, with occasional light sanding between coats to get rid of what I call sins - drools and streaks. Shellac dries fast, so the light coats can be applied at the rate of several per hour.

Rubbing alcohol is isopropyl alcohol. The "proper" solvent for shellac is ethanol - the alcohol in booze - so it is expensive and highly taxed and regulated. If you add a few percent of methanol (chemically similar but poisonous) you have denatured alcohol, so it is no longer booze but works the same. The alcohol you can buy at the hardware or paint store is denatured alcohol, occasionally called DNA. The isopropyl alcohol you used was close enough to screw up the finish, but should be put back in the medicine cabinet and never be used on finish again.

What you did next is, in my opinion, worse. Spray wax often contains silicone, guaranteed to screw up any new finish you apply. Old English Oil is a mystery to me, but I know it is never recommended among those who post their mistakes on forums. If you want to wax your furniture use Minwax or Johnson's paste furniture wax. Like waxing a car - rub it on, let it dry, polish it off. Not as easy as spray wax, but it works and lasts - you redo it every couple years, not every week.

Paint thinner (mineral spirits) is a solvent for many of the waxes etc. that might be on a table - despite the name it does not dissolve paint, varnish, lacquer, or shellac once they have dried. It does not dissolve all the food that may be dried on a table in almost invisible spots, so when I refinish a table, I clean mutlple times with warm soap and water, alternating with mineral spirits.

The cloudiness in a lacquer or shellac finish is often moisture trapped when the finish is soft (either by applying in a humid environment or by applying alcohol to shellac.) Often the trapped moisture can be removed by applying a thin coat of the finish (shellac thinned with DNA, or lacquer thinned with lacquer thinner). A purist will tell you to buy lacquer crystals and dissolve them. I cheat and buy it pre-mixed at Home Depot. Zinsser Bulls Eye is the most common brand - if you find it labeled Shellac, it is a 3 pound cut (fairly thick) and you want it thin, so use 1/3 from the can to 2/3 DNA, making what experts call a 1 pound cut. If it is labeled Seal Coat (sold as a clear primer) it is the same thing in a 2 pound cut, meaning add equal parts DNA to get the thin one pound cut I am suggesting you use. Apply a thin coat of this thin shellac, and see if the cloudiness disappears. If so, add a few more coats and declare a victory. If not use the DNA to remove the cloudy shellac, then refinish.
 
I am NOT a finishing expert.

Going along with what the other people said, one very nice thing about an alcohol (shellac) finish is that it can be repaired.

Now, what you need to do is repair it. HOW?

Go the extra mile, with MORE DNA not rubbing alcohol. Scrub the finish with DNA to finish removing what is there. After the top is all cleaned off, and yes, you WILL apply a GENEROUS amount of elbow grease, the top will be ready to reapply any good finish of your choosing.

IF - perhaps, we made a mistake and the table finish is NOT shellac, then the only thing that will happen is that the table top will get a really good cleaning.

Again - I am NOT a finishing expert.
 
Adding to what Charlie said - the 'rubbing' alcohol you used was likely only about 70% alcohol. The other 30% is water, which is what caused the clouding.

Following Charlie's advise ought to help with your problem.
 
I'm not a finishing expert either, but I bought a 65 year old house 34 years ago that has the entire family room and adjacent kitchen completely done in full thickness knotty pine, and the finish is amber shellac. I needed to make several modifications to the kitchen, just simple things like moving and replacing the wall oven, installing a matching cabinet where a refrigerator had once been located, building three drawers and cabinet to replace the lower part of the original oven location, and raising the height of the wall above the refrigerator/freezer so that a modern refrigerator/freezer would fit. A dishwasher was also installed, requiring the cutting and removal of an existing original cabinet. The original wood was actually Fir, so it had a pinker color than white pine. I used one coat of Min-wax Ipswitch Pine stain to put the slightly pink color of Fir onto the white pine that I had used and then covered that with two coats of Zinnser Orange Shellac. Other than a few holes left in some original wood, there is no color difference between the original wood and my modifications.

I'm not saying that Orange Shellac is the answer to your prayers, but it might be, and it is easy to find already mixed. Zinnser has found a way to make their shellacs last longer than most shellacs do. Normally, to get fresh shellac, you have to buy shellac flakes of the right color and then dissolve and mix them into Denatured Alcohol. Orange shellac was a very common finish for dining room furniture 60 or more years ago, but only a little experimenting will determine if you can get the color to match. There are many different colors of shellac, but orange is one of the more common. There is also clear, and many darker shades. A professional painter supply shop might be able to suggest which color shellac is on that table. Shellac dries to the touch very fast, so spraying it might be the best way to achieve a smooth finish. There is a technique called "French Polishing" where the shellac can be rubbed in while adding small amounts of DNA to produce a smooth finish without spraying, but it takes lots of practice. You might also try to find someone who has restored antique furniture, since they likely have a lot of experience with shellac and french polishing. An experienced person can probably repair the finish without removing it all. I've done small areas of my kitchen, but would not attempt repairing the finish of a dining room table.

How about a few "Before" photos of the damage? Maybe I can make better suggestions after looking at them. Then after it's fixed an "After" photo or two would be great too.

Charley
 
Adding to what Charlie said - the 'rubbing' alcohol you used was likely only about 70% alcohol. The other 30% is water, which is what caused the clouding.

Following Charlie's advise ought to help with your problem.

I agree on both points. :thumb: The water in the rubbing alcohol most likely caused the cloudiness, and Charlie's suggestions should do the trick to fix it.
 
I just want to thank everyone for their suggestions. Yes, it was a bad call on my part. Sick about it. Have called a couple of local places that do refinishing. Quotes have ranged from $300 to $800...which is more than I paid for the dining set. When I get around to following Charlies' advice, I be sure to take before and after pics...might be a while though.
 
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Quick question, do I need to do anything to first remove the spray wax and Old English I applied before applying a thin coat of the finish (shellac thinned with DNA, or lacquer thinned with lacquer thinner)?
 
You will need to remove everything right down to the old finish, do a real thorough job of it.

Re-read Charlie's post below.



" I bet the problem is that the finish was shellac, which is crystals produced by the lac bug dissolved in alcohol. When applied, the alcohol evaporates and leaves the ... shelLAC. When a second coat is applied the alcohol partially dissolves the first coat, making the coats blend together, called burn in. A typical finish is many thin coats applied, with occasional light sanding between coats to get rid of what I call sins - drools and streaks. Shellac dries fast, so the light coats can be applied at the rate of several per hour.

Rubbing alcohol is isopropyl alcohol. The "proper" solvent for shellac is ethanol - the alcohol in booze - so it is expensive and highly taxed and regulated. If you add a few percent of methanol (chemically similar but poisonous) you have denatured alcohol, so it is no longer booze but works the same. The alcohol you can buy at the hardware or paint store is denatured alcohol, occasionally called DNA. The isopropyl alcohol you used was close enough to screw up the finish, but should be put back in the medicine cabinet and never be used on finish again.

What you did next is, in my opinion, worse. Spray wax often contains silicone, guaranteed to screw up any new finish you apply. Old English Oil is a mystery to me, but I know it is never recommended among those who post their mistakes on forums. If you want to wax your furniture use Minwax or Johnson's paste furniture wax. Like waxing a car - rub it on, let it dry, polish it off. Not as easy as spray wax, but it works and lasts - you redo it every couple years, not every week.

Paint thinner (mineral spirits) is a solvent for many of the waxes etc. that might be on a table - despite the name it does not dissolve paint, varnish, lacquer, or shellac once they have dried. It does not dissolve all the food that may be dried on a table in almost invisible spots, so when I refinish a table, I clean mutlple times with warm soap and water, alternating with mineral spirits.

The cloudiness in a lacquer or shellac finish is often moisture trapped when the finish is soft (either by applying in a humid environment or by applying alcohol to shellac.) Often the trapped moisture can be removed by applying a thin coat of the finish (shellac thinned with DNA, or lacquer thinned with lacquer thinner). A purist will tell you to buy lacquer crystals and dissolve them. I cheat and buy it pre-mixed at Home Depot. Zinsser Bulls Eye is the most common brand - if you find it labeled Shellac, it is a 3 pound cut (fairly thick) and you want it thin, so use 1/3 from the can to 2/3 DNA, making what experts call a 1 pound cut. If it is labeled Seal Coat (sold as a clear primer) it is the same thing in a 2 pound cut, meaning add equal parts DNA to get the thin one pound cut I am suggesting you use. Apply a thin coat of this thin shellac, and see if the cloudiness disappears. If so, add a few more coats and declare a victory. If not use the DNA to remove the cloudy shellac, then refinish."

Charlie Plesums, Austin Texas
(Retired early to become a custom furnituremaker)
Lots of my free advice at www.solowoodworker.com
 
Basically, things need to be removed in the reverse order that you put them on. Use the appropriate solvent and change as you go through the layers.
 
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