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OTusing wood bleach to remove stains (dog piss) in oak floor

aribert

Cast Iron
Joined
Jul 2, 2008
Location
Metro Detroit, MI
I'm refinishing a red oak floor in a foreclosure we bought recently. One room appears to have been the dog(s) latrine. I acquired a two part (gallon each) sodium hydroxide wood bleach sold by Duraseal/Minwax. Anyone have experience using a two part bleach? I have tried to read up on wood bleach, but most of the articles I came across seemed like they copied the same generic information from each other. The two part bleach is supposed to be the strongest bleach used to remove stains and/or lighten wood. Somewhere I read that bleach could damage the wood but the article did not give any further info. I don't have a lot to loose - the floor is already damaged.

I am thinking that I'll apply the bleach after the 60 grit pass - I presume several iterations of bleaching - I intend to use a small chip brush only on the stains and not the surrounding wood. And then continue with the 80 & 100 grit (guessing that I will need to stain the floor to hide the residual urine staining - I would prefer not to stain if I can lighten the spots enough). Does this seem reasonable or do I need to apply the bleach earlier/later in the sanding sequence?


Finally does anyone know what the shelf life of two part bleach is and what issues may arise if one uses "expired" bleach? I bough the bleach for a different project several years ago but that project got put on hold. The bleach containers have a note on the label that states that the bleach maintains its effectiveness up to 6 months if the containers are unopened. My two bleach containers are unopened but years old now.


Any advise, information, suggestions are appreciated. Worst case I carpet the room - killed the smell w/ Odoban and expect to do that again after sanding. TIA.
 
I tried something similar on a huge table top that had sat under a couple roof leaks for a long time. The result wasn't all that great. The two part bleach was oxalic acid and peroxide. Peroxide decomposes to water and oxygen over some period of time so I wouldn't bother with bleach that has been sitting around. Problem I had was that it did lighten the wood, but all the wood not just the stained area. It really didn't remove the stain, just lightened everything a couple shades. Tended to be blotchy too. I applied the bleach two or three times but ended up staining the whole thing a medium dark to get it to look decent. I don't think I'd do it again. Hopefully you have better luck.
 
Did this accidentally by getting Ospho on some aged red cedar. It did bleach the wood but hard to get the bleached area to match the unbleached area. You can dilute it with water to get less of an effect and try to blend it ...
 
As its a urine stain on oak much of the colour will be the tannins reacting with ammonia and compounds. I'd use a weak oxalic acid solution several times after sanding.
 
I have also used oxalic acid with varying degrees of success to remove old animal piss stains on a white oak floor. The acid tended to fade, rather than totally remove the very dark/black stains. After some researching I found that a few yacht/ boat restorers recommended another product * to remove iron stains from wood. I tested/used it on the floor and it worked great, and removed most of the stains completely. It did somewhat lighten the entire stain area but once stained and finished this blended in fine. It is a 100+ year old floor which when even after sanded had a “patina” to it which probably contributed to everything blending in well after the staining/ finishing.

* Rust Stain Remover

MILO
 
Worst case I carpet the room - killed the smell w/ Odoban and expect to do that again after sanding. TIA.

Red Oak is the cheap seats. One room is the only problem, might be less total labour to just tear it out and lay NEW? If not whole room, then the stained portion, plus a bit - good pulls comingled with new and re-laid, for a faster and better match-up?

BETTER CASE.. if you must, is you stabilize and seal the old wood, then overtop it with an engineered "wood" laminate instead. Our place in Virginia I DID tear-out badly laid Red Oak as had gaps and squeeked like a "nightingale" floor, doubled the subfloor to inch and a quarter, put down a nice laminate.

Now it is actually around 2/3rd through-body porcelain, on-grade slab and lower ground floor, laminate other than three baths, upper floor of a 3-level split.

Cleaning machines to suit (Oreck orbital, Hoover rotary-bristle sudser/scrubber & wet vac / drying vac mode).

Hong Kong flat, tile for kichen, both baths, otherwise 100% rather lovely Teak fingerblock. Because in the Orient, one can still doo that.

:)

Interim maintenance to either isn't at all onerous. "Spot" with a swiffer or an "almost dry" sponge-mop and done.

Neither is actually "cold to the feet". House slippers exist anyway.

Any dirt shows more obviously than carpet, but less of it can accumulate or hide stuff that GROWS. Or wants to do.

Far, FAR too much biological diversity takes up housekeeping in carpet, even if it APPEARS to be clean.

Hong Kong's humididity, heat, and aggressive tropical biosphere?

Carpet wouldn't last two years before it was growing stuff would just as well eat of HUMANS.
 
I had a similar problem with cat urine. The floor was heart pine. Tried oxalic acid, then a card scraper.
Wound up removing the entire floor and replacing it with Maple flooring. I saved the heart pine that was unaffected by the urine. About ten years later a fellow asked me what I did with the old flooring. He was a flooring installer and finisher that was asked to remove the stains by the realtor that sold the house to me. He told them at that time the floor should be replaced as heart pine was old growth and very hard to come by. Any way I told him I stickered flooring in the attic. He looked at it and offered me $9.00 a bf. There was 150 SF . I sold it for $1350.00
He needed 60 SF to finish a renovation.
I would remove the floor and replace it with a new flooring of your choice.
mike
 
I had a similar problem with cat urine. The floor was heart pine. Tried oxalic acid, then a card scraper.
Wound up removing the entire floor and replacing it with Maple flooring. I saved the heart pine that was unaffected by the urine. About ten years later a fellow asked me what I did with the old flooring. He was a flooring installer and finisher that was asked to remove the stains by the realtor that sold the house to me. He told them at that time the floor should be replaced as heart pine was old growth and very hard to come by. Any way I told him I stickered flooring in the attic. He looked at it and offered me $9.00 a bf. There was 150 SF . I sold it for $1350.00
He needed 60 SF to finish a renovation.
I would remove the floor and replace it with a new flooring of your choice.
mike

Old family farm had become a rental, 20-odd years by the time I bought it from Dad. Soon after, had me a new tenant, was also there over fifteen years. Tried HARD to find a way to sell it to him when I divorced. No Joy, his situation was too badly compromised to raise even the modest mortgage.

Much as we had tried to help, he went angry at ME! Well.. maybe the banks ALSO.

Moved to another roof, kept up the rent, but turns out he had put a major flock of ducks into the upstairs, easily as many chickens into the basement for close-on two months.

You can guess the rest.

Ammonia & nitrates accumulation in what HAD been carpet OVER old growth pine so strong the new owner figured if it had dried-out good it might have blown the whole place to flinders!

Wasn't "young" when bought in 1943, we rebuilt it, re-soded it, re-roofed it, move interior partitons .. twice.. three times if yah count lifting it up off hand-cut stone pylons for excavating the basement it had not had.

This go, new flooring was only the wrap-up, not the beginning!

Over 30 years ago, now. But Google shows it still stands.

Framed in solid full thickness local wood, right off the land. "Weed of the forest" we called it then.

Hickory.

Same large genetic family as the Walnuts and Pecans, just not as valuable, given how long each hammer handle can last.

HAD to be locally sawyered. Have to frame it in the green, else it twists like a snake with a broken back. Get it to dry in-place or patiently lay it up, proper-like? Stays arrow-straight, strong, and serious-durable.

More than a hundred years and counting.

Pine, yah nail to. Oak, ya drill.

Hickory? Welll. Once dried-out it surely ain't gonna stick-weld worth a damn, is it?

:)

May as well just clamp stuff to it 'til Ramsets came affordable!
 
Worst case I carpet the room - killed the smell w/ Odoban and expect to do that again after sanding. TIA.

If you are having an issue with a wood floor then just wait until you have to deal with puddles on a carpet. I gave up years ago. It's better to have shitty carpets
and a nice buddy than just nice carpets with a cold shivering dog outside in the cold all alone. In my neighborhood I don't even like the people who do that to a dog.

I bet I have the worst looking carpets for miles in all directions. I like stone floors, tile floors and area rugs.

Down boy.

TheGuy.jpg
 
If you are having an issue with a wood floor then just wait until you have to deal with puddles on a carpet. I gave up years ago. It's better to have shitty carpets
and a nice buddy than just nice carpets with a cold shivering dog outside in the cold all alone. In my neighborhood I don't even like the people who do that to a dog.

I bet I have the worst looking carpets for miles in all directions. I like stone floors, tile floors and area rugs.

Down boy.

View attachment 283288

Phht! Canides are evolved "den dwellers". They don't WANT to mess where they live, will housebreak themselves well-enough just given attention to when they are trying to tell yah "It's time NOW!"

Dog's prolly think humans are the heathen savages for keeping toilets inside our living space rather than outside of it. Waste odours attract predators as might eat our pups, y'see.

Yah know a male dog has adopted yah as "people" and "worthy family" when before momma can git a diaper onto a baby learning to use a "potty", her loyal dog has scarfed up the baby's poo, then signals for the door.

He didn't do that for desert. He's just doing what he'd do for his own mate in his OWN den, "transporting" the only way he can .... so momma and the pups don't have their den stink and risk their well-being.

You'd have to know dogs?

:D
 
Yah know a male dog has adopted yah as "people" and "worthy family" when before momma can git a diaper onto a baby learning to use a "potty", her loyal dog has scarfed up the baby's poo, then signals for the door.
Yup.......:D
 

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I cleaned up some old growth pine stained at the head of the tub. sanded then bleached the last thing. Bleach really only cleans the surface so if you sand after you expose new stained wood.


Dunno about smells, would be worried piss soaked into lower layers, and will come back on nice summer days
 
I cleaned up some old growth pine stained at the head of the tub. sanded then bleached the last thing. Bleach really only cleans the surface so if you sand after you expose new stained wood.


Dunno about smells, would be worried piss soaked into lower layers, and will come back on nice summer days

No big deal. It polymerizes.

You've heard of poly-urine-stain varnish, have you not?

;)
 
Thank you all that provided suggestions and past experience.

Turns out my two part wood bleach was still effective (even after mixing a small batch and letting it sit in an open container overnight). Adh2000 mentioned that the beach lightening everything, so I used a 1 inch chip brush to apply it only to the stains. Eventually I ended up with a stain ring on the perimeter with a lighter center. I then used a acid brush to apply and finally I trimmed about 2/3 of the bristles off of an acid brush to apply the wood bleach to the stain ring. All in all I am pleased with the results and did not need to stain the floor to hide the (former) stains in the floor. Knowing where the stains were, I can still see the remnants of the stains but I had to point the locations out to my wife who did not see the stain remnants when looking at the finished floor.

I also had tannic (sp?) acid spots where a former owner left the window open when it rained and there were numerous spots from the tack strip nails and carpet pad staples. I used Whink Rust Stain remover as suggested by Milo74 and had mixed results. The Rust stain remover definitely lightened the spots (superficially) but any further sanding brought them back again almost as dark as before. I could have left the stain remover on longer or applied after the final sanding but since I am using this product off label, I was concerned about adequately neutralizing it before applying the water-based sealer and varnish.

In addition, I also used a deck washing solution called Deck Bright to pull the dirt out of the bare spots in the wood. I used it too sparingly in this room with minimal results - I just had to sand a bit longer to get down to clean wood. I did use the Deck Bright aggressively on later oak refinishing in the house - stairs and on a parquet floor in the kitchen prior to sanding with good results - significantly lightened up the dirt staining before I began sanding.
 








 
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