Lightening before Henna. Good or bad idea?

Have you tried 10 vol with your current bleach? This is why it is best to use a top quality salon brand, you get more lift with low volume peroxide. If I were bleaching your hair I would use 10 vol for the amount of lift you want.
Plus you can never assume how your current hair will respond based on past experiences, this is why you are strand testing. You need to see how these exact products work on the hair you have now
To get different volumes of peroxide you have to mix/dilute, so 15 vol would be half 20 and half 10 vol, or 30 vol diluted with an equal amount of shampoo for  a 15 vol bleach bath etc

No, bleaching natural pigment and dye are completely different. You should never compare them because it's like comparing oranges to plastic apples!

Yes, you are correct, and I have finally learned that. However, it seems that even my virgin hair is very resistant to lightening. Not as resistant as dyed hair (of course), but still very resistant. I used to dye my hair with salon dye and 30-vol peroxide many years ago, and it took significantly longer than was stated in the instructions in order to get the needed lift. I don't think it's unheard of.

It still doesn't take away from the fact you can't compare them. I made no comment on how resistant your hair may or may not be. So when talking about lightening your hair, never even think about it if your hair isn't dyed now. Dyed hair isn't resistant, it just needs to be treated differently 🙂

I made a mistake in comparing them, and will not do so again.

Wicked Pixie, you saved me!!! Your advice about strand testing directly the hair on my scalp was invaluable, and I can't thank you enough!

First I was skeptical, why should I do it, et cetera, and then I decided to do it. I used 20 volume peroxide, again the same ratio, 1:2 bleach & developer. I applied it from root to the end of the strand. Now before you read any further, remember that this is the same 20 volume bleach which took 40 minutes on the cut off hair strand to get to the coppery light brown color in the picture I posted.

Anyway, so after applying it on the strand, I sat down and waited. After about 5 minutes I looked in the mirror, and I noticed lightening. I thought "hmm, the hair is very wet, it must be an illusion, as it cannot lighten this fast". After 5 more minutes, a total of 10, I look at it again, and it looks significantly lighter. So I wash it out.

The result: It lightened more after 10 minutes than it did after 40 minutes on the "external" strand test.

WOW! I mean really... WOW. This was COMPLETELY unexpected.

It seems that the heat from the scalp does not only affect the roots, but all of the hair. It affects the roots the most, but the entire hair is affected by it. About 1 - 1.5 cm of the roots are indeed a bit lighter than the rest, but it's not really drastic.

Why do I say you saved me? Well because, imagine if I had put on the 20-volume bleach on all of my hair and waited 40 minutes. Enough said.

After doing this experiment, it seems that bleach bath with the 20-volume does seem to be a nice option indeed, and might even be the ideal one. Or even 10-volume peroxide with bleach.

I still can't believe what it did in 10 minutes. Now there is a risk if I apply the 20-volume bleach directly, that it will turn out uneven, because it lightens so fast that I might not even be done with all of my hair and the 10 minutes would be over. Then again, I don't have long hair, but it still worries me. So it seems 10-volume bleach directly or 20-volume bleach bath would be the two most rational solutions.

I would need to go buy a 10-volume developer, because I only have 20 and 30 at home.

Thank you again, Wicked Pixie!

I meant to say before, but kept forgetting, sorry! Yeah, heat from the body does make a difference. When I saw you'd done a strand test with no heat, I meant to say then. I got distracted and didn't send the post I'd written. After that I forgot the time I did post.

Though, it just goes to show, hair is often not as resistant as we think it is 🙂

Strand tests are so vital, they give us so much information, so never skip the strand tests with bleaching.
If you want to avoid unevenness and damage, definitely drop to 10 vol.
Even a professional would struggle to get an even result with a 10 min processing time. It takes practice to get bleach on evenly, each strand must be totally saturated, and bleach has a texture very different from regular hair dyes, it doesn't spread or stick easily so it needs applying carefully with a tint brush on hair that is separated into small sections.
Watch some videos of professionals applying bleach, generally they work in pairs to get the bleach on as quickly as possible for an even result. Guy Tang (ideally with the sound off lol) is great at demonstrating sectioning and bleach application
Diluting the 20 vol to make a bleach bath may make it easier to apply, the shampoo really alters the texture, so you can squidge it into the hair to ensure it fully covers

I'm slowly getting frustrated, for several reasons. -r-

I'm tempted to simply try the bleach wash, because it sounds the easiest, but I'm afraid of hot roots. People say it wouldn't cause hot roots because it's gentler/diluted. My logic tells me that hot roots will still be a problem, because the dilution only means that the entire hair will lighten slower than with regular bleaching, but roots will still be most affected from the heat off the scalp. How am I wrong in this assumption?

Second problem is, if I decide to do a regular bleach myself, I'm afraid I will just mess everything up. My hair isn't long, but I absolutely fail when trying to section it or apply parts to only one section, et cetera. Since I have to work pretty fast even with a low volume bleach, I think I will start to panic trying to cover everything as fast as possible.

Third problem is, this strand test I've done on my head, will have to be avoided whatever I choose to do. It shouldn't be that hard to avoid when doing regular bleaching, but what about a bleach wash? Would I need to wrap aluminum foil around it so the shampoo doesn't touch it? I guess that's the only way.

So yeah, I have done lots of tests throughout the last several days and have had a lot of patience. Now I want to finally get it over with, but I don't know how, and it angers me.

For what it's worth, I went to some stores here in Germany looking for 10-volume developer, and the only thing they had was 4%, which is 13 volume. If I want 10, I'd have to order it off the internet.

You can dilute 20 into 10 using conditioner, shampoo or water. Yes, this does effectively make it a bleach bath. 13 is better than 20, but what is bad about buying from the Internet? I do it all the time. It's often the only way I can get good bleach powder.

I say bleach baths don't cause hot roots, in the same way, because theres usually so little lift that the difference between roots and lengths isn't noticeable generally.

If you do the actually applying of the bleach in a cool room then you'll have a lot more time to work with it. Then you can move to a warmer room for the processing. That will buy you a lot of time to work. If you're really worried about it, do it in two or three sections. Start with the bottom of your head and work up, only rinsing the section you have worked on, not your whole head (it's fine to rinse a section you already worked on.

I'd wrap the test sections in cling film personally. No chance of reaction and it'll be easier to move around. You can smoother them in conditioner too. It wouldn't stop the bleach if you just applied it directly, but it'll slow down any if it got on there by accident and it'll also help the cling film cling!

I have been dying/bleaching my hair for 28ish years now, roughly every 6 weeks. I still have a bit of a panic that it's all going to go  horribly wrong.

The thing about the bleach bath is, I actually do need it two to three shades lighter, so I worry it might be too mild?

Nice idea about putting conditioner on the tested strand!

As i said in my first reply, don't try and do your whole head at once.
Hot roots will be an issue even if you dilute the bleach, always apply to roots after you have saturated the mid lengths and ends. If you want a natural look, slightly darker roots will be better than slightly lighter
Even a bleach bath mix will need to be applied carefully, you cant just slap it on and expect even results.
If you can have somebody help you it will be much easier, bleaching is a tricky process.
You can also practice sectioning and application with a thick conditioner.

Ok I forgot to update this thread. So a few weeks ago I went ahead and did it. The end result is really wonderful, exactly the way I wanted it.

There were some problems however. I first did a bleach bath with 20 volume peroxide. It acted very slowly, and took about 50 minutes to reach the desired shade. The problem was that the roots were a tad lighter, but the back of my hair didn't lighten as much as my other hair. The lighter roots weren't the classic hot roots, but they were still a bit lighter. This was my mistake, because even though I applied the mixture to the ends first, I thought everything would act must faster, so I applied it on the roots a bit too soon, and that's why it came out that way. Why the back of my hair didn't lighten as much, I'm really not sure.

Either way, after washing my hair and drying it, I fixed the darker parts by applying 20 volume bleach directly (without shampoo), and after that, everything was very even, and looked great.

The next day I applied Henna and got a really nice color, exactly the way I wanted it. I will post a pic or two soon, so people can see the results. Even if I hadn't applied the Henna, the results were very nice, but the Henna made it even more to my liking.

So yeah, that's my experience.

Thank you all for giving me advice. 🙂