Thread: Bleaching white beech timber

Hi Dengue . Get some Amonia . I use 3% from super market. I used to use much stronger and it didn't make much of a difference for bleaching.

I used to buy Hydrogen Peroxide from the chemist . 500 ml , 25Vol I think it was. I now buy that in larger containers though so go elsewhere. Try the chemist.



Tip into two containers one of each a little more than the amount you want to use.
Apply the amonia to the wood . Then apply the peroxide. Keep everything separated. Don't dip the peroxide brush in the amonia or the amonia into the peroxide. Dilute and throw out any excess. If you try saving contaminated excess back into your clean soloutions and it has any of the other stuff mixed in it can explode with time. It just takes longer if its contaminated with tiny amounts . Mix it 50 / 50 and you have a big expanding Hot reaction . So the mixing takes place on the wood. If you want to try steering the bleaching affect then dilute the peroxide with water. When the two parts are put onto the wood the bleaching takes place very quickly, within 8 seconds, but you wont see its effect until it dries completely.
I do tests and heat gun dry it off.


Rob

Thanks Bob, really appreciate your sharing of your knowledge and experience.
How do you clean the timber after the bleaching process is finished and before applying the lacquer ?
I have read using white vinegar somewhere in the process. Are you familiar with this and what would be the aim?
Also, what protective gear do you use, esp when using ammonia?

Vinegar is used to neutralize stripping with Caustic soda . By doing that I think your reversing a caustic solution that has dried out with an acid. How does it necessarily end up at a PH of 7 though ?

I don't think I've heard of it being done after Bleaching . Maybe I did years ago ? I don't do that though. If I feel something is left over I wash it down with water or wipe it over with metho.

Protection . If I use the very strong amonia there are masks I use that help filter it . Mainly though I do it outside in a breeze. With a mask if it needs it. With the 3 % its fine though. No mask and inside with a door open near the job. Getting the peroxide on you is the worst part. Nothing stops it reacting on the skin and doing a strange white stinging sort of burn . Its uncomfortable . And goes away in half an hour. I use gloves and take care. Glasses for eyes.Or a face mask . I always manage to get a bit on me with large jobs though.

Woolworths sell Cloudy ammonia my wife uses to clean the oven, comes in 1 litre plastic bottle. No indication of strength. Would this work OK, do you think Bob?

Originally Posted by Dengue

Woolworths sell Cloudy ammonia my wife uses to clean the oven, comes in 1 litre plastic bottle. No indication of strength. Would this work OK, do you think Bob?

Yes. That's the 3% stuff I use . I'm pretty sure its 3%

Supreme Cloudy Ammonia 1l | Woolworths

I think I read 3% years ago from a similar supermarket product .
The label says nothing about 3% now on these.

Here's the Peroxide I use as well as the Cloudy Amonia.

IMG_2110a.jpg IMG_2111a.jpg IMG_2112a.jpg IMG_2113a.jpg

Rob

Rotating pictures is doing my head in today. Think Ill leave it like that and you can rotate if you download .

here is some alternative opportunities using oxalac acid

Experimenting with Bleaching Wood - YouTube
How to Remove or Lighten Stains on Wood using Oxalic Acid - YouTube
general Google search https://www.google.com/search?client...UTF-8&oe=UTF-8

calabrese55

Originally Posted by auscab

I think I read 3% years ago from a similar supermarket product .
The label says nothing about 3% now on these.

Here's the Peroxide I use as well as the Cloudy Amonia.

IMG_2110a.jpg IMG_2111a.jpg IMG_2112a.jpg IMG_2113a.jpg

Rob

Hi again Rob, do you think this Woolies Hydrogen Peroxide will be strong enough?
Sanofi Hydrogen Peroxide Powerful Bleach Liquid 200ml | Woolworths

Originally Posted by Dengue

Hi again Rob, do you think this Woolies Hydrogen Peroxide will be strong enough?
Sanofi Hydrogen Peroxide Powerful Bleach Liquid 200ml | Woolworths

No I don't think it will be strong enough. Its the strength of the peroxide that does the work.
The Amonia is alkaline . Other alkaline soloutions can be used with differing effects. Like a really strong alkaline like caustic soda and the same peroxide does a very strong job of bleaching. The cloudy amonia does a good enough job most of the time . If you want a driftwood efffect use Caustic soda. And stand back for a severe reaction.

I'd go ask a chemist for a bottle of 50% or see how strong they can get. They sell it on ebay but its pick up only in Sydney.

Originally Posted by calabrese55

here is some alternative opportunities using oxalac acid

Experimenting with Bleaching Wood - YouTube
How to Remove or Lighten Stains on Wood using Oxalic Acid - YouTube
general Google search https://www.google.com/search?client...UTF-8&oe=UTF-8

calabrese55

Thanks for that calabrese55

Oxalic acid is great stuff but it doesn't bleach wood of its natural colours . It does a great job of removing stains and dirt. Iron oxide stains . Some ink stains . Oxidised deck boards. Probably more but that is what Ive used it on in furniture restoration.

Put it on any fresh wood no matter how strong the mix and its like putting water on it.
Ive got a 20 kg bag of the stuff I bought 30 years ago and I'm slowly going through it . Removing those types of stains.
Don't ever get it in a cut on your finger. DAMHIK

An alkaline followed by Hydrogen peroxide is a good way of bleaching wood and being able to steer the effect from light to severe. Same as the hair dressers do woman's hair at the salon. My wife the hair dresser by trade does the same thing with an alkaline paste then peroxide. She buys bottles for hair in different strengths. I buy as strong as I can get and water it down.

Rob