Masterbatch, dual lye and Vinegar

It took me quite a while to get the sb right. And even longer to accept the fact that my favorite recipe is fine for any swirls you want a medium trace for, but that I have to use a variation for more intricate swirls. Even longer still, as in last week, to accept that I have to use mica for black in the intricate ones as well, instead of ac.

mx6inpenn said:

It took me quite a while to get the sb right. And even longer to accept the fact that my favorite recipe is fine for any swirls you want a medium trace for, but that I have to use a variation for more intricate swirls. Even longer still, as in last week, to accept that I have to use mica for black in the intricate ones as well, instead of ac.

Click to expand...

Why do you have to use mica instead of AC in the intricate ones?

penelopejane said:

Why do you have to use mica instead of AC in the intricate ones?

Click to expand...

Every time I use ac it thickens up just a bit quicker than the portions with micas. Just easier if they are all at the same place.

mx6inpenn said:

Every time I use ac it thickens up just a bit quicker than the portions with micas. Just easier if they are all at the same place.

Click to expand...

I notice that about TD and some micas that have TD as part of the ingredient to get the color shade, too apparently. It takes a lot of practice, I suspect to learn to deal with all these little variations.

earlene said:

I notice that about TD and some micas that have TD as part of the ingredient to get the color shade, too apparently. It takes a lot of practice, I suspect to learn to deal with all these little variations.

Click to expand...

I agree. It's just easier for me to use the mica, so I will do so from now on and save the ac for more simple swirls.

The Efficacious Gentleman said:

Do you actually want any potassium acetate? Does it have the same impact as sodium acetate?

Could you add enough NaOH directly to neutralise the vinegar and then add in the other 128g NaOH and 7.5g KOH to make your 50% solution? Would you need a touch more liquid to make sure all the lyes are dissolved, though?

Click to expand...

Hi TEG,
You are right I do need to masterbatch my lye with vinegar (so I can use different liquids as the left over "water" component).

I only want to masterbatch the NaOH with vinegar.
I masterbatch my KOH with water and will add separately because I want to ensure I get the total KOH that I need to be added. I don't trust that it will be evenly distributed. Probably silly but that is the way I would like it.

So to make a 1:1 masterbatch lye/vinegar do I use 1 kg neutralised vinegar and add 1 kg NaOH to it?
Is that enough water (vinegar)? Or since vinegar is only 95% water do I have to calculate for that too?

I don't think anyone has an accurate answer for you. I think you're going to have to do an experiment and find out.

If you use 100 grams vinegar to make a nearly saturated solution of NaOH, only 95 g is water. Looking at this simplistically as if the vinegar behaves just like water, you should be able to only dissolve about 95 g of NaOH in 100 g of commercial vinegar. But you're also doing chemistry while you dissolve the NaOH -- you're making sodium acetate. I'm not certain what the solubility of NaOH would be in a mixture of water and sodium acetate.

DeeAnna said:

I don't think anyone has an accurate answer for you. I think you're going to have to do an experiment and find out.

If you use 100 grams vinegar to make a nearly saturated solution of NaOH, only 95 g is water. Looking at this simplistically as if the vinegar behaves just like water, you should be able to only dissolve about 95 g of NaOH in 100 g of commercial vinegar. But you're also doing chemistry while you dissolve the NaOH -- you're making sodium acetate. I'm not certain what the solubility of NaOH would be in a mixture of water and sodium acetate.

Click to expand...

So the only problem will be the inability of the NaOH to dissolve in that amount of liquid? I don't have to add 5% more vinegar (or water) to NaOH g to make up the water in the recipe?

Is this the right thing to do? I want to add say coconut milk to a recipe but if my lye is premixed with water I can't add the milk because I need 50% vinegar as well. I don't want to mix the milk with lye because of the smell (which the soap retains) and the discolouring.

"...So the only problem will be the inability of the NaOH to dissolve in that amount of liquid? I don't have to add 5% more vinegar (or water) to NaOH g to make up the water in the recipe? ..."

If you find you can't dissolve 100 grams of NaOH in 100 grams of vinegar, you will have to add more liquid to get the NaOH to dissolve. Or use less NaOH for a given volume of vinegar.

Either way you end up in the same place -- NaOH is not going to be at 50% of the mixture. If that happens, you'll have to adjust your math accordingly to get the correct amount of NaOH in your soap batches.

As I said before, I don't have a good answer whether this will happen or not -- you're going to have to experiment to figure it out.

Ok I'll try it and if it doesn't dissolve I'll have to come back and get help with the maths.

I still think I might need 5% more water anyway to make the vinegar into water and acetic acid mix. I can't work out TOMHs post at all in relation to masterbatching.

Slight tangent, but on the subject of sodium acetate vs potassium acetate, shouldn't sodium's higher electronegativity favor that reaction? For that matter, aren't they salts dissolved in solution anyway? That is, separated?

BrewerGeorge -- You may well be right, but I don't think acetic acid is as strong an acid as sodium or potassium hydroxides are strong bases. So it's likely that there will be some acetate molecules floating around as well as ions. But that's just a guess on my part.

penelopejane said:

I am trying to Masterbatch, dual lye and Vinegar.

My recipe has 95% NaOH and 5% KOH
NaOH= 128 g
KOH = 7.5g
Total water = 316g

I have masterbatched the lye already so I want to add 50% water.
316 - 128 - 7.5 = 180g vinegar instead of water

28 g of vinegar neutralises 1 g NaOH
95% of 180g = 171 g NaOH/28 = 6 g NaOH extra

28 g of vinegar neutralises 1.4 g KOH
5% of 180 g = 9 g KOH/28 = 0.32 x 1.4g = 0.45 KOH extra. (DeeAnna says to leave this out as it is negligible)

Click to expand...

What I have done wrong here is that I have forgotten to multiply the 180g vinegar * 95% (since vinegar is only 95% water) = 171 g water from vinegar

So need 316g total water - 128 - 7.5 - 171 g vinegar = 9.5 extra water

I think this is why my soap set up so quickly.

DeeAnna said:

I don't think anyone has an accurate answer for you. I think you're going to have to do an experiment and find out.

If you use 100 grams vinegar to make a nearly saturated solution of NaOH, only 95 g is water. Looking at this simplistically as if the vinegar behaves just like water, you should be able to only dissolve about 95 g of NaOH in 100 g of commercial vinegar. But you're also doing chemistry while you dissolve the NaOH -- you're making sodium acetate. I'm not certain what the solubility of NaOH would be in a mixture of water and sodium acetate.

Click to expand...

Hi DeeAnna,

I mixed 96 g of NaOH in 100g of vinegar (my vinegar is 4% wouldn't you know so I had to adjust the figures) and it was perfectly clear. Added the extra 4 g of NaOH and it won't dissolve in.

So can you please tell me what I have to do to make this up to 200 g so I can use it as a 50% lye masterbatch solution? If I hadn't added the extra 4 g NaOH I could just add 4 g of water and that will make this the perfect masterbatch couldn't I?

I'd have to add more NaOH to neutralise the vinegar, later.

My DH is asking why I have to complicate everything until it is beyond comprehension but I'd really like to use vinegar and different additives for the water component and masterbatch as well if it is possible. If it doesn't make sense I can just not masterbatch it.

DH thinks there might be a required sequence to go through to make soap (NaOH + water then later add vinegar if wanted) and that I could be messing with that in such a way that I will not be able to predict and might not get saponification.

You could won't be able to get a 50% solution with water, sodium hydroxide, and something else. Sodium hydroxide needs as much water as itself by weight to fully dissolve. If there is sodium acetate also in the water, you will have to use less sodium hydroxide.

You could try 45g of NaOH for every 100g of neutralized vinegar which means a bit more complex calculation when it comes to using it, but if you want I could walk you through a simple excel to calculate how much solution you would need to use for x grams of lye

The Efficacious Gentleman said:

You could won't be able to get a 50% solution with water, sodium hydroxide, and something else. Sodium hydroxide needs as much water as itself by weight to fully dissolve. If there is sodium acetate also in the water, you will have to use less sodium hydroxide.

You could try 45g of NaOH for every 100g of neutralized vinegar which means a bit more complex calculation when it comes to using it, but if you want I could walk you through a simple excel to calculate how much solution you would need to use for x grams of lye

Click to expand...

That would be great. I would really like something that is easy to calculate like 100 g of NaOH or 100g of neutralised vinegar. But you would need to go slow because it's difficult for me.

Open excel (((don't actually enter the speech marks, they are just there to show what you need to enter)))

In cell a1 put "45" and in b1 put "solution strength"

In a2 put "100" and in b2 put "required NaOH"

In a3 put "=(100/a1)*a2"

The = is needed to let excel know that a formula is coming.

You can now enter your solution strength in a1, your required lye in a2 and then in a3 it will tell you how much total solution you need

You might want to adjust the rounding or just round the solution amount yourself to get a more workable number.

I agree with what The Gent said. If your experiment shows you can't dissolve 100 g of NaOH in 100 g of vinegar, you can't do it.

His suggestion to make a standard mix at a lower % of NaOH is the only realistic option for you.

The only thought I have -- and bear in mind I'm a bit fuzzy since I haven't got my coffee yet -- If you put "45" in your spreadsheet as the NaOH concentration AND you use vinegar for the liquid, I would think the answer calculated in Cell A3 would need a correction to allow for the NaOH that will become sodium acetate. The formula is fine for water, but I'm not sure it's correct for vinegar.

I was assuming that you take, say, 1000g of vinegar and neutralize it to make a mix of "water" and sodium acetate. Would you not be able to make a 45% solution with that?

Part of the reason why I left that part able to be edited rather than a hard-written part of the formula, so if you can only make a 40% solution when you are using neutralized vinegar you can adjust that figure

"... I was assuming that you take, say, 1000g of vinegar and neutralize it to make a mix of "water" and sodium acetate...."

But, with respect, that's not what PJ did -- she said she added 96 g NaOH to 100 g vinegar. She didn't first make 100 g of sodium acetate solution and then find how much NaOH she could add to that solution. Based on what she did, the total % of NaOH added to the vinegar was about 48.5% by weight of solution, but some part of that NaOH is acetate and some is not. Without doing the math (or another experiment), we don't exactly know those answers.

"...Would you not be able to make a 45% solution with that?..."

You'd have to back-calculate how much of that 96 g of NaOH she added was converted to acetate. That will tell you how much of that NaOH is still available for making soap. In other words, is the NaOH consumed by the acetate reaction 48.5% - 45% = 3.5%? If so, then yes, you can make this solution the way she did it and get an effective 45% NaOH solution for making soap.

Most people, and I imagine PJ is among those, won't want to look at the problem in two steps - (1) neutralize the vinegar with NaOH and (2) add extra NaOH for their soap making masterbatch. They will want to measure vinegar, measure NaOH, mix the two, and know the % effective NaOH available for soaping, which is something less than the % total NaOH added to the mixture. The formula can be adjusted to spit out that number.