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Ask The Doc A Question!

Question:

Thanks for your message from a few minutes ago. I would like info on the new chemical and other means of extracting wax embedded in the grain of floors prior to applying the topcoats.

Answer:



Dear Guy

I must say first off, that a lot of these old floors really should be chemically stripped or completely resanded. Recoating over questionable old finishes to save money or to not create dust, sometimes is a lost cause. You might also read the second part of my floor maintenance article, and learn how to identify the make up of these old floor finishes. Recoating with only a water based finish doesn't always get good results. And all water based finished tend to whiten in 5-10 years, and this added opaqueness may be disturbing to some customers. The article is free don't worry.

But I digress.

The first thing one should do when approaching an old floor finish is to test the adhesion of this original finish. Remove any wax from this test area. Take a razor and cross hatch a small area where the floor finish is sound. Apply a piece of duct tape and rip it off. If more than 20 % of the finish come off the cross hatch, you do not have a good base for recoating. If you go ahead and recoat this floor and the finish fails (it will) the clients will blame you, and you may have to pay for a complete resand.

Even still, when you do recoat, it's best to go through the entire prep and recoat process again on a small area. I usually charge 50 dollars for this (which is deductible from the job). Let the small test area's finish cure for 1 or 2 weeks (depending on the finish) and do the adhesion test again. If it fails, have them opt for a resand.

I know you don't have the drum sanders and edgers for this type of job yet, but you should be able to find a small company (one man ops) in your area, that is willing to do resands, while you still handle the finishing of the floors. This way you can handle any wood floor restoration situation, and your business will grow exponentially.

Sorry I digressed again.

So let's say you have a floor that is waxed, but just what kind of wax is it. A paste wax is solvent based, and can be dissolved with mineral spirits on a rag. Also a water wetted fine steel wool pad will gather a grey smudge on it when wiped across. There is another type of wax called an acrylic polish. Mop and Glo is still a popular brand of this stuff.

Water based acrylic waxes like Mop and Glo will be harder to dissolve and generally need an ammonia based wax stripper to remove them. Most of these acrylic polishes will give the surface a patchy, dirty appearance when they start to wear off. You can test for these types of waxes by mixing a tsp. of water with a tsp. of household ammonia, then add a drop of liquid detergent, into a small cup. Apply a drop of this mixture on a clean area that you suspect has this acrylic wax and wait 5 minutes. If this type of wax is present the spot will turn white. You can only remove this wax with an ammonia based mop stripper. The Cleaning Center (www.cleanreport.com) makes a Mop Stripper that will remove the most stubborn acrylic type wax, without introducing too much water to the floor.

But let's get back to the paste wax removal which has been vexing you so much. Although mineral spirits is effective at wax removal, Naphtha is far more effective. It dries quite quickly without leaving behind a oily film (like mineral spirits will) and so is a lot more compatible when preparing for a water based finish. But use a wash bottle and a hand operated nylon scrub pad on a pole to wet and dissolve the old wax. And before the solvent dries up blot it off the floor with lots of paper towels. You have to go over the whole floor in 3 foot rows, systematically so all the wax is removed. Next, once that dries (you should ventilate well with fans for safety and speed) scrub and dry the floor again with a very diluted solution of TSP. You will need to rinse off the TSP with clear water unfortunately adding another step with this stuff

Instead of TSP you might consider using the Basic Coating's product called IFT (intensive floor treatment) at

http://www.basiccoatings.com/asp/contractors/prod_tykote.asp

You will be superior results using the Basic Tykote system and their water based coatings. They been in the water based finishing business a lot longer than the Flecto group has. Better more durable finishes. And the IFT does not need to be rinsed, saving a step.

Anyway, once the IFT or (rinsed) TSP has dried, wash the floor again with a PH neutral cleaner or BC Squeaky Clean. Let the cleaner dry. All the wax should be gone. So now, screen the floor with a 100 grit screen. It should not clog up. If the screen clogs, you have not de-waxed the floor well enough, you'll have to start all over.

After screening, vacuum and tack rag with naphtha or mineral spirits again. Then coat the floor with a moderate layer (500 square ft/gal) of de-waxed shellac. Seal Coat is the only brand I know that is truly de-waxed.

http://www.zinsser.com/product_detail.asp?ProductID=72

You can apply your de-waxed shellac with a 3/8" nap Purdy Brand (phenolic core) roller, easily and quickly.

Let this dry and maroon pad the shellac coat, (don't use a screens, it melts the shellac), vacuum and tack again and apply what ever finish you want to the floor. Water based or oil based are both fine to use over this type of shellac. The shellac will have also done a nice job at filling in some of the deep scratches. When you tack rag a floor that is to be coated with water based use non oily Naphtha instead in mineral spirits.

So you see Guy, all this is very labor intensive, but it works in most cases. Companies offering this sort of service often offer a warranty, that if the finish peels within a year, they will credit half the amount spent on recoating to the more expensive full resand and finishing job. So be sure to leave a quote for that also. Farming out the sand only jobs (done the Doc's way according to the Sanding w/o Machine Marks article ) still gives you complete control on the finishing of these floors. Make a lot more money, and always have all the options at your disposal. The world will beat a path to your door. Good Luck. (oh, I won't be able to answer any follow ups until I'm out of the hospital)

Any more questions you may have on this subject or clarifications of your original question feel free to write again at no cost. I hope you have enjoyed this personal service, real human responses are the best.

As always your Most humble servant, Joseph, the Wood Floor Doctor.-

You may also find these articles helpful:

1. How To Sand Wood Floors Without Leaving Machine Marks

2. How To Chemically Strip Wood Floors without dust!

3. Plank Floor: What Special Considerations This Type Of Floor Raises

4. Should I sand the wood floors myself or hire a pro

5. How To Take Care Of Your Health And Safety when Installing, Finishing, Repairing or Cleaning your wood floors