Jump to content
Maestronet Forums

Recommended Posts

Posted


I appreciate it if you can tell me what stain I can get to do the same job ( as a replacement) under UV … I used stain 421 or old wood , Ground A …

now I have only for one more instrument left and buying only once product will be expensive from their website… I was wondering if there is some common wood oxidation stain to be found easily , locally or eBay , but I couldn’t find any … that’s why I ask for help … 

is there something I can get locally or from eBay to do the same job

thank you 

  • Arsalan changed the title to Oxidation stain option
Posted

Chemical oxidation of wood is a dangerous business. Even when taking the proper handling precautions, the wood prep and finishing steps, if not done right, can ruin the effect.

Here are some common options in order of increasing danger that can yield great results, but I strongly urge you to investigate the processes thoroughly before attempting them.

- vinegar and steel wool with optional tea or coffee pretreatment

- potassium dichromate

- sodium hydroxide

- fumed ammonia

The vinegar/steel wool option is a combination stain/oxidizing solution so requires special care when finishing the wood after treatment.

The others will oxidize the wood through the surface and will be highly resistant to changes due to aging.

There is a lot to be said about using modern, high quality, alcohol based dyes or simply stuffing the wood in a UV box for a few days. Or go with a tried and proven commercial treatment like in Joe Robson's post.

Good luck!

Posted
32 minutes ago, ctanzio said:

Chemical oxidation of wood is a dangerous business. Even when taking the proper handling precautions, the wood prep and finishing steps, if not done right, can ruin the effect.

Here are some common options in order of increasing danger that can yield great results, but I strongly urge you to investigate the processes thoroughly before attempting them.

- vinegar and steel wool with optional tea or coffee pretreatment

- potassium dichromate

- sodium hydroxide

- fumed ammonia

The vinegar/steel wool option is a combination stain/oxidizing solution so requires special care when finishing the wood after treatment.

The others will oxidize the wood through the surface and will be highly resistant to changes due to aging.

There is a lot to be said about using modern, high quality, alcohol based dyes or simply stuffing the wood in a UV box for a few days. Or go with a tried and proven commercial treatment like in Joe Robson's post.

Good luck!

I would add sodium nitrite and potassium nitrite to the list, and remove potassium dichromate because it is known to be carcinogenic.

Posted

I have spent a lot of time figuring out wood staining.  You can do it very cheaply.  Try different ways on scraps, including end grain, and see what you think.

The easiest and in many ways the best is wood ash lye.  Boil 2 parts water (by weight) and one part ash for 90 minutes and filter the resulting liquid.  This is a very gentle chemical stain that will not burn end grain.

Sodium nitrite 5% solution.  You can buy the dry crystals on line dirt cheap and mix the solution yourself.  Cures under UV lights.  The result is pinkish and you can burn end grain easily.

Potassium permanganate 1% solution. You can buy the dry crystals on line dirt cheap and mix the solution yourself.  The result is a wonderful tan brown.  But it will interact with any wood dust trapped in your grain and give a burnt appearance.  You really need to scrape every surface before using.

I am also experimenting with Van Dyke crystals, but I think this will be too unpredictable.

Posted

Are you trying to regain color after scraping your instrument?

I would agree with tea, but it can be uneven and is not lightfast.  Some use aniline dye.  Whatever you apply, you have to wait for it to completely dry for days before varnishing.  

Posted
3 hours ago, Davide Sora said:

I would add sodium nitrite and potassium nitrite to the list, and remove potassium dichromate because it is known to be carcinogenic.

Anyone know how to keep sodium nitrite and potassium nitrate light-fast? I've heard that they can fade over time as well. 

Posted
35 minutes ago, Nick Allen said:

Anyone know how to keep sodium nitrite and potassium nitrate light-fast? I've heard that they can fade over time as well. 

 

9 minutes ago, Shunyata said:

Chemically I cannot imagine why these nitrite/nitrates wouldn’t be color fast.  They convert to nitric acid and oxidize the wood.

I don't know how to fix this problem, I don't have much experience with nitrites. Applying them with the addition of vinegar improves things a little (but I don't know if it makes others worse...). However, I also noticed this fading over time, several samples that I had made left for months to take the light from the window have lightened a lot, but do not fade completely, the color remains darker than the original untreated wood. In any case were samples of wood treated with nitrite without anything else on top, I believe this fading diminishes greatly once covered and protected by the varnish.

Posted
7 hours ago, Shunyata said:

Potassium permanganate

My experience with Potassium permanganate is that it was fugitive.  I used it in conjunction with yellow, red & black aniline dies to get a ground colour but the effect faded after application of spirit varnish.  I stripped the varnish a couple of years later and the only colour that remained was the bright yellow aniline.  

Here are pics before varnish, then after stripping varnish 2 years later. White balance is different between the pics but if you compare violin with benchtop you can see difference is actually more that it looks:

1157.thumb.jpg.76874dd1cad034d2d6b87cbe26394aaf.jpg

1000003114.thumb.jpg.dac349850ed634aaf882c19b788cb74d.jpg

Posted
7 hours ago, Nick Allen said:

Anyone know how to keep sodium nitrite and potassium nitrate light-fast? I've heard that they can fade over time as well. 

My experience is that fading occurs around 9 months and ends up sort of gray.....but that was a long time ago so I can't find the samples....it was before phone cameras.

on we go

Joe

Posted

It is important to note that the chemistry of wood oxidation is complex and can involve both the tannins in the wood and the various sugar complexes of the cell walls. Simply mixing a bunch of chemicals together willy-nilly and brushing the solution onto the wood can yield wildly varying results.

Try to find a scientific paper on the specific type of chemical treatment you want to try. Then carefully follow the solution preparation and application steps.

For example, poor preparation of the popular steel wool and vinegar solution can result in an intense red liquid with lots of red gunk that is mostly rust and Fe(II) based compounds. Even after filtering, the resulting reaction with wood tannins can be weak and fading.

But a preparation to fully dissolve the steel wool while also drastically reducing the amount of solids precipitating out of the liquid will yield a light red solution very high in Fe(III) concentration. This will drive the tannins into stable macro-molecules with strong color changes.

Posted
On 11/23/2023 at 5:51 AM, joerobson said:

My Aged Wood Gold is useful for this.

Picture is before and after the initial reaction.

on we go,

Joe

AWC Gold before and after.jpg

Is it to be used after first layer of casein or gelatin ? 
thanks 

Posted
20 hours ago, ctanzio said:

It is important to note that the chemistry of wood oxidation is complex and can involve both the tannins in the wood and the various sugar complexes of the cell walls. Simply mixing a bunch of chemicals together willy-nilly and brushing the solution onto the wood can yield wildly varying results.

Try to find a scientific paper on the specific type of chemical treatment you want to try. Then carefully follow the solution preparation and application steps.

For example, poor preparation of the popular steel wool and vinegar solution can result in an intense red liquid with lots of red gunk that is mostly rust and Fe(II) based compounds. Even after filtering, the resulting reaction with wood tannins can be weak and fading.

But a preparation to fully dissolve the steel wool while also drastically reducing the amount of solids precipitating out of the liquid will yield a light red solution very high in Fe(III) concentration. This will drive the tannins into stable macro-molecules with strong color changes.

I used  a few options … and lastly I used Italian golden ground A+B from oldwood varnish , it works well and I had better result compared to stain 421 for example … but I ran out of them … and I was wondering if I can replace only this A+B ground with something else as they are expensive and buying them only will be more expensive… 

I appreciate it if you tell me what material you prefer and you had a good result with ? 
those are both water stain , so I wanna replace them with something water base ( as I am following all other steps of oldwood varnish … and oldwood works really well … 

Posted
On 11/23/2023 at 5:51 AM, joerobson said:

My Aged Wood Gold is useful for this.

Picture is before and after the initial reaction.

on we go,

Joe

AWC Gold before and after.jpg

Thank you for sharing 

Posted
On 11/23/2023 at 7:39 AM, Shunyata said:

I have spent a lot of time figuring out wood staining.  You can do it very cheaply.  Try different ways on scraps, including end grain, and see what you think.

The easiest and in many ways the best is wood ash lye.  Boil 2 parts water (by weight) and one part ash for 90 minutes and filter the resulting liquid.  This is a very gentle chemical stain that will not burn end grain.

Sodium nitrite 5% solution.  You can buy the dry crystals on line dirt cheap and mix the solution yourself.  Cures under UV lights.  The result is pinkish and you can burn end grain easily.

Potassium permanganate 1% solution. You can buy the dry crystals on line dirt cheap and mix the solution yourself.  The result is a wonderful tan brown.  But it will interact with any wood dust trapped in your grain and give a burnt appearance.  You really need to scrape every surface before using.

I am also experimenting with Van Dyke crystals, but I think this will be too unpredictable.

Thank you Dan 

I read about ash from you, you wrote about it before 

I would like to choose one thing that works and for now stick to it … I may try it on scrap piece and see the result . It’s a good idea actually… cheap , no sorry , free … lol 

Posted
6 hours ago, Arsalan said:

I appreciate it if you tell me what material you prefer and you had a good result with ? 

I do not use oxidizing agents.

I do an initial ground with highly diluted blonde shellac.

If the wood is too light, I will add a color coat with some diluted blonde shellac with high quality alcohol-based dyes, or use a few coats of diluted amber or garnet shellac.

Then finish with oil-based varnish.

Posted
1 hour ago, ctanzio said:

I do not use oxidizing agents.

I do an initial ground with highly diluted blonde shellac.

If the wood is too light, I will add a color coat with some diluted blonde shellac with high quality alcohol-based dyes, or use a few coats of diluted amber or garnet shellac.

Then finish with oil-based varnish.

What are some high-quality alcohol-based colors which you have found not to change color or intensity with time or UV exposure?

Posted
On 11/23/2023 at 12:53 PM, Nick Allen said:

Anyone know how to keep sodium nitrite and potassium nitrate light-fast? I've heard that they can fade over time as well. 

For what it's worth:

While I might not choose to color a newly made instrument with sodium nitrite (though I am aware some use it in this manner), and avoid using it on critical structural parts, I have found sodium nitrate provides a relatively stable color when exposed to UV and then sealed. I've often found it handy toning wood on replacement edges when the results are warranted for example. An advantage is that it does not tend to darken glue lines.

I generally use  5% or less on maple, and 3% or less on spruce.  Haven't had difficulty with it  "burning" the end-grain at those levels.  Testing on cutoffs of matching scrap is important so you are aware of "what you'll get" and it can tend to send the reeds on some spruces toward the red spectrum... If it's acute, I use a different method, but a slight reddish tint on the reeds can usually be corrected during touchup.

 

Posted
4 hours ago, David Burgess said:

What are some high-quality alcohol-based colors which you have found not to change color or intensity with time or UV exposure?

One example: Transtint dyes added to shellac as a toner, then finished with oil-based varnish have not faded for me for objects subject to normal indoor use. Some pieces, including a violin, date back to about 10 years.

Don't know how it would fare under extended direct sunlight or in a UV cabinet. My experience is limited to browns and reds. 

Posted
1 hour ago, Jeffrey Holmes said:

While I might not choose to color a newly made instrument with sodium nitrite (though I am aware some use it in this manner), and avoid using it on critical structural parts, I have found sodium nitrate provides a relatively stable color when exposed to UV and then sealed.

I have seen and had some very nice looking results with sodium nitrite (from crystals), exposed to UV, and I am aware of quite many makers who use it.  Are there warranted concerns about it degrading the wood structurally? Historical proof? I know there is with nitric acid, and if I understood right then some aspects of the oxidation process are similar?

Where (from what) do you obtain sodium nitrate? Is the look similar to nitrite?

On 11/24/2023 at 3:28 AM, joerobson said:

My experience is that fading occurs around 9 months and ends up sort of gray...

Anyone else noticed this effect, and maybe there is a way of sealing that would reduce that?

 

I have seen strange results from both pot. permanganate and iron vitrile solutions, violins turning purple and green respectively from pH reactions. Possibly the ground was not well sealed,  which allowed that, but in any case it was not desirable!

I have used sodium and potassium hydroxide on necks for color, it's usually quite yellow, but with some earth pigments can work well. Would be wary of it on spruce. More "natural" wood ash lye is intriguing, will have to try.

Does anyone here have experience with lime and casein, as I have seen some use? I haven't tried it myself but like the idea of sealing and coloring in one step, as well as protecting from both moisture and bugs (in theory).

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.


×
×
  • Create New...