How to remove water stains from wood before refinishing

[mrybas]

Hi,
I’m redoing the wood trim in my galley. Some of the wood is stained from where the old bright work wore through allowing the wood to get wet.
How can I remove the dark stains? I tried a little hydrogen peroxide, but not much improvement.

[s/v Jedi]

Use teak cleaner like from Star Brite. This used to be oxalic acid but they may use more advanced formulas today.

[Cheechako]

The only sure way I know is to sand it off . But try the cleaner, it may work, depends on how porous the stained wood is.
Fiddle rails like that are nice left bare teak if you maintain them... avoids this issue. The water gets under the finish where it meets the counter.

[Calif.Ted]

Oxalic acid AKA woodbleach is usual, available in tubs in powder form it's available at most hardware stores.

[eje]

Originally Posted by s/v Jedi

Use teak cleaner like from Star Brite. This used to be oxalic acid but they may use more advanced formulas today.

You aren't going to want to use the Starbrite Teak cleaner. It works well for cleaning teak but it's meant for "external" use. You have to hose it off thoroughly after you scrub it.

I contacted Stanbrite customer service to see if it was suitable for my interior wood. They said it was not

[mrybas]

Originally Posted by eje

You aren't going to want to use the Starbrite Teak cleaner. It works well for cleaning teak but it's meant for "external" use. You have to hose it off thoroughly after you scrub it.



I contacted Stanbrite customer service to see if it was suitable for my interior wood. They said it was not

Agree. I have used it on exterior bright work on a previous boat and an hose down was necessary.

[mrybas]

I think the wood is Kauri. The boat was built in NZ.

[keepondancin]

You will need to strip the finish off, then use Oxalic acid/wood bleach. Let it sit awhile, keeping it damp with light coats of the solution. Rinse it off well, be creative, use a sponge and water and keep wiping it, and rinsing the sponge. Let it dry well, then decide if you need another application. Sand to make the wood uniform, then varnish. You might want to use a sealant aroung the inside of the fiddle to prevent water from getting under the fiddle and wicking up into the wood again. It will work. I have done that in numerous similar situations.

[s/v Jedi]

Originally Posted by keepondancin

You will need to strip the finish off, then use Oxalic acid/wood bleach. Let it sit awhile, keeping it damp with light coats of the solution. Rinse it off well, be creative, use a sponge and water and keep wiping it, and rinsing the sponge. Let it dry well, then decide if you need another application. Sand to make the wood uniform, then varnish. You might want to use a sealant aroung the inside of the fiddle to prevent water from getting under the fiddle and wicking up into the wood again. It will work. I have done that in numerous similar situations.

Exactly, I assumed people would know rinsing off with a hose inside a boat wouldn’t work well and use a bucket and sponge instead

Oxalic acid has been used for this for at least a century and I think for even longer than that.

[Captain Anthony]

Following

[captstu]

When I bought my project gemini 3400, all of the interior wood was damaged from several leaking hatches, a number of leaking through holes, and two leaking port lights.

Use your imagination.

After repairing the leaks, replacing all the side and front windows with new Lexan, and re-batting all the chain plates, I was satisfied the boat was leak frer.

I stripped the entire boat down to nearly white wood with oxalic acid dissolved in hot water at the rate of 1/2 cup per gallon using a garden sprayer. I washed it with freshwater and vacuumed the mess out with the shop vac until the water ran clear. At this point my friends decided I should just burn the boat to the waterline.

I stained all the interior wood with a light oak stain I gave it the look of the original teak. I then put two coats of satin varnish

The boat didn’t look new but it did look quite good and it smelled new. I kept her about five warriors and sold it to a lucky new owner..

[kish]

Oxalic acid has been used professionally by boat builders to bleach wood after it was steamed to allow bending /shaping,


Sand the wood down to bare wood to remove all previous coatings.
Make up a solution of oxalic acid and water and add it to wallpaper paste, and apply that paste to the wood. which will stay damp while in contact for 30 minutes, defendant on ambient temperature.
Rinse and repeat as necessary. Rinse clear when a satisfactory patina has been achieved.
.

.

[sailcrazy]

From my experience, the Oxalic acid will do just what everyone has said....it will bleach your wood. It will be uniform (more or less) but near white/ie, bleached. Then you'll need to stain it, and then finish it. IF...that's what you want, that's your answer. But if you want to preserve the wood color/texture/look, ie, clean it but not bleach it-maybe another direction may be better. I've had really good luck with Semco 2-part teak cleaner, although I've only used it on teak and no other exotic woods. If bleaching is not your goal, it may be worth a try?

[Ryban]

I'm working on re-finishing most of our interior wood where the varnish has worn down. I'm now getting to our cabin sole, and my standard procedure has been to completely sand away the varnish in places where it is highly worn, and sand it clean where it's still in decent shape.

I have been using Oxalic acid to try and clean stains/dark spots out of the teak with some success, but have not developed a good technique. The mixing with wall paper paste is an interesting idea. I've also tried sprinkling oxalic acid crystals and bar keepers friend directly on the wood, spraying with water from a spray bottle, and using a sponge or magic eraser to work into the wood. I've also tried just spraying a concentrated mixture of oxalic acid on the wood.

What other tips do people have? I do think the oxalic treatment works, but only after a long period of time -- a 15-30 min soak is not sufficient in my experience.

I also use generous amounts of water and a sponge to try to get any remaining acid out of the wood before varnishing, but still worry deep down that the varnish will fail one day because of residual oxalic acid.

Here is a before and in-progress photo. The patch is a location where I'm testing oxalic acid treatments before committing to the entire sole.

[captstu]

I bought an old gemini several years ago with badly discolored interior wood. It had been oiled 10 years before and water had leaked on it in a number of places.

I bleached it nearly white with a solution of 1/2 cup oxalic acid powder and 1 quart of the hottest water. I could stand in a little pressure sprayer. The oxalic acid did its thing in a bit or so that I just read stuff whatever was left, leaving a wood uniformly bleached to a dearly white fetish.

I restain the wood after it was dry with walnut strain, but ended up making it look like teak again had applied three coats of varnish.

In the places where the plywood a D laminated, I applied a second coat of epoxy to the underlying wood and pressed the vaneer back of the place .

it did not look like fine cabinetry, but it did look quite good