Wood floor finish help.

string · April 21, 2008, 6:11pm

-- Last Updated: Apr-21-08 2:11 PM EST --

I got such great advice on the door, I have to ask. We took a carpet up and there is an unfinished oak floor under there.Someone apparently spilled something and there is about a foot square water stain in one spot. Looks like a one-time incident .Other than sanding, is there a method to remove it before varnishing the floor?It is no longer wet.

system · April 21, 2008, 6:31pm

http://ideas.reliableremodeler.com/Artic
The first step to removing deeper stains is to mask off the area around the stain so that the non-stained areas are protected. Next, remove the old finish and or wax and then use oxalic acid to remove the stain and bring back the original color of the wood. Once the area is dry, simply re-stain or seal it to match the surrounding floor. With some care and attention to detail, removing water stains from wood floors can be relatively simple.

system · April 21, 2008, 6:34pm

http://www.oldhouseweb.com/stories/Detai
These methods include using household chlorine bleach, oxalic acid, or a concentrate hydrogen peroxide solution.

PRODUCTS

2.01 MATERIALS

NOTE: Chemical products are sometimes sold under a common

name. This usually means that the substance is not as pure as

the same chemical sold under its chemical name. The grade of

purity of common name substances, however, is usually adequate

for stain removal work, and these products should be purchased

when available, as they tend to be less expensive. Common

names are indicated below by an asterisk (*).

A. Denatured Alcohol:

Other chemical or common names include Methylated

spirit*.
Potential hazards: TOXIC AND FLAMMABLE.
Available from hardware store, paint store or

printer’s supply distributor.

B. Mineral Spirits:
A petroleum distillate that is used especially as a

paint or varnish thinner.
Other chemical or common names include Benzine*

(not Benzene); Naphtha*; Petroleum spirits*;

Solvent naphtha*.
Potential Hazards: TOXIC AND FLAMMABLE.
Safety Precautions:

a. AVOID REPEATED OR PROLONGED SKIN CONTACT.

b. ALWAYS wear rubber gloves when handling

mineral spirits.

c. If any chemical is splashed onto the skin,

wash immediately with soap and water.
Available from construction specialties

distributor, hardware store, paint store, or

printer’s supply distributor.

C. Chlorine Bleach:
Other chemical or common names include Bleaching

solution*; Household bleach*; Laundry bleach*;

Sodium Hypochlorite*; Solution of chlorinated

soda*.
Potential Hazards: CORROSIVE TO FLESH.
Available from chemical supply house, grocery store

or supermarket, hardware store or janitorial supply

distributor.

D. Oxalic Acid (COOH)2 or (H2C2O4):
A poisonous strong acid that occurs in various

plants as oxalates and is used especially as a

bleaching or cleaning agent and in making dyes.
One of the strongest organic acids.
Other chemical or common names include Dibasic

acid; Ethanedioic acid; Acid of sugar*.
Potential Hazards: TOXIC; CORROSIVE TO CONCRETE,

STEEL, WOOD OR GLASS.
Available from chemical supply house, dry cleaning

supply distributor, drugstore or pharmaceutical

supply distributor, hardware store, or photographic

supply distributor (not camera shop). (Often sold

under a manufacturer’s brand name; the chemical

name may appear on the label.)

E. Hydrogen Peroxide (H202): The concentrate solution used

for wood bleaching - typically sold as a two-part kit

containing sodium hydroxide.
An unstable compound used especially as an

oxidizing and bleaching agent, an antiseptic, and a

propellant.
Other chemical or common names include Peroxide of

hydrogen*; Solution of hydrogen dioxide*;

Superoxol*; (hydrogen peroxide is commonly sold as

a 3% solution; Superoxol is a 30% solution;

Superoxol causes flesh burns; 3% hydrogen peroxide

does not). THIS PROCEDURE CALLS FOR USE OF THE 30%

CONCENTRATION.
Potential Hazards: TOXIC (when concentrated);

CORROSIVE TO FLESH; FLAMMABLE (in high

concentration).
Available from chemical supply house, drugstore,

pharmaceutical supply distributor, or hardware

store.

F. Clean, soft cloths

G. Clean, potable water

2.02 EQUIPMENT

A. Glass or porcelain container

B. Stiff bristle brushes

C. Sponges

D. Vacuum

PART 3—EXECUTION

3.01 PREPARATION

A. Wash wood using denatured alcohol to remove any dirt or

other impurities from the surface.

B. Sand the wood and remove any paint or varnish. Brush

and/or vacuum dust and debris from the surface.

C. Remove any grease or oil from the surface by washing with

mineral spirits and a clean, soft cloth.

3.02 ERECTION, INSTALLATION, APPLICATION

CAUTION: DO NOT MIX AMMONIA WITH CHLORINE BLEACHES, A POISONOUS GAS WILL RESULT! DO NOT USE BLEACH ON BIRD

DROPPINGS.

NOTE: TEST CLEAN A SMALL AREA BEFORE PROCEEDING WITH THE WORK TO DETERMINE THE BEST METHOD FOR REMOVING THE STAIN.

NOTE: TOTAL REMOVAL OF A STAIN MAY NOT ALWAYS BE POSSIBLE. IN THESE CASES, LIGHTENING OF THE STAIN MUST SUFFICE. ON THE

CONTRARY, BE PREPARED FOR BLEACHED WOOD TO APPEAR LIKE-NEW IN CONTRAST TO SURROUNDING WOOD THAT APPEARS MORE AGED.

NOTE: BLEACHES ARE WATER-BASED SOLUTIONS AND TEND TO RAISE THE WOOD GRAIN WHEN APPLIED; THIS WILL REQUIRE SANDING UPON COMPLETION.

A. Stain Removal Using Household Chlorine Bleach:

Recommended for removing an aniline dye finish and ink

stains from wood.

NOTE: BE SURE TO PROVIDE PLENTY OF VENTILATION; USE

PROTECTIVE GLOVES.

CAUTION: DO NOT MIX CHLORINE BLEACH AND AMMONIA. THIS

WILL PRODUCE A TOXIC GAS.
Apply bleach to the stained area using a clean,

soft cloth or stiff bristle brush. Use straight

from the bottle; do not dilute.
Allow to sit on the surface for at least 10

minutes; reapply if necessary.
Thoroughly rinse the surface with clean, clear

water.
Allow to dry for at least 24 hours before

refinishing.

B. Stain Removal Using Oxalic Acid: Recommended for

removing blue ink stains, iron stains and darkening or

blackening of wood due to age or previous cleaning.

NOTE: BEST TO USE IT WARM AND CONCENTRATED.
Dissolve crystals in hot water in a glass or

porcelain container.
Apply the solution liberally to the surface using a

clean, soft cloth or stiff bristle brush.
Allow to sit on the surface for at least 10

minutes. It may take longer (up to an hour) to

achieve effective results depending on the type of

stain and type of wood; agitate with a stiff

bristle brush if necessary to aid in stain removal;

reapply if necessary.
Thoroughly rinse the surface with clean, clear

water.
Allow to dry for at least 24 hours before

refinishing.

C. Stain Removal Using Concentrated Hydrogen Peroxide (30%):

Recommended for lightening woods or as a last attempt at

removing a stain before resorting to replacement.

NOTE: HYDROGEN PEROXIDE AT THIS CONCENTRATE IS THE

STRONGEST OF THE THREE BLEACHES LISTED. IT IS TYPICALLY

SOLD AS A TWO-PART KIT CONTAINING SODIUM HYDROXIDE.
Dampen the wood using a sponge soaked in clean,

clear water.
Apply mixture of hydrogen peroxide and sodium

hydroxide uniformly over the surface. Follow

manufacturer’s recommendations for application

procedures and dwell time.