dissolving lye
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From a practical point of view in the context of soap making, 100 grams of NaOH will dissolve in 100 grams of water. That is a 50% solution of NaOH.
From a theoretical point of view, 111 grams of NaOH will dissolve in 100 grams of water at 68 deg F (20 C). Translated into the terms you are using, 100 g NaOH will dissolve in 90 g water. That is a 52.6% solution of NaOH.
I would make a saturated solution (the 52.6% solution) in the lab without blinking, but I would stick to the 50% solution for soapmaking. There is a much lower chance of getting undissolved bits of lye in my soap.
Hope this helps.
From a theoretical point of view, 111 grams of NaOH will dissolve in 100 grams of water at 68 deg F (20 C). Translated into the terms you are using, 100 g NaOH will dissolve in 90 g water. That is a 52.6% solution of NaOH.
I would make a saturated solution (the 52.6% solution) in the lab without blinking, but I would stick to the 50% solution for soapmaking. There is a much lower chance of getting undissolved bits of lye in my soap.
Hope this helps.
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Thank you. Did you ever use 50% lye solution?
I'm asking this because if I want a soap with 100% OO using 1000 grams of oil, SoapCalc recomands a water quantity of 38% of oil weigth - this means 380 grams - and a quantity of lye of 129 grams. 129:380 = 34%. In general, SoapCalc gives a concentration of 33-34% for lye solution. Is 34% more safe than 50%?
Why SoapCalc computes the water amount as a percent of oils amount? Why not to compute water amoun from lye amount?
I'm asking this because if I want a soap with 100% OO using 1000 grams of oil, SoapCalc recomands a water quantity of 38% of oil weigth - this means 380 grams - and a quantity of lye of 129 grams. 129:380 = 34%. In general, SoapCalc gives a concentration of 33-34% for lye solution. Is 34% more safe than 50%?
Why SoapCalc computes the water amount as a percent of oils amount? Why not to compute water amoun from lye amount?
I often make soap at a 40% lye solution and never go over 33% even for hot process. From my experience 33% is good for an all olive oil soap. The water used helps with the soaps solubility and I find that using 40% in a Castile makes the soap a bit dry and harder to lather even in hot water.
To answer your question, yes, I have used a 50% solution of NaOH to make soap, but it takes longer to get the NaOH dissolved when making that concentrated of a lye solution. A 33% to 40% lye solution mixes up easier and doesn't cause my soap batter to trace quite so fast. Most of the time, I stick with the 33%. (All these percentages are the % of NaOH in water, just to be clear -- not % based on the oil weight). Just my preference.
"...Is 34% more safe than 50%?..."
I suppose it is, marginally. But no matter what % you use, you're making a highly concentrated caustic solution. Nothing to play around with. Even the usual 27-28% concentration will cause severe burns in a heartbeat.
"...Why SoapCalc computes the water amount as a percent of oils amount? Why not to compute water amoun from lye amount?..."
I completely agree with you. Basing the weight of water as a % of the oils makes utterly no sense from a chemistry point of view. Industrial soap making for over a century calculates the lye required from the saponification value of the fats and calculates the water required based on the lye amount. I think it's just one of those odd ideas, along with the idea of "water discounting", that come from the early days of modern handcrafted soap making.
The default in SoapCalc is to calculate the water based on oils, but you can also specify the lye solution concentration -- click on "Lye Concentration" right below "Water as % of Oils" and enter the NaOH concentration as a percentage. Stick with the method that makes the most sense to you, and you'll be good.
"...Is 34% more safe than 50%?..."
I suppose it is, marginally. But no matter what % you use, you're making a highly concentrated caustic solution. Nothing to play around with. Even the usual 27-28% concentration will cause severe burns in a heartbeat.
"...Why SoapCalc computes the water amount as a percent of oils amount? Why not to compute water amoun from lye amount?..."
I completely agree with you. Basing the weight of water as a % of the oils makes utterly no sense from a chemistry point of view. Industrial soap making for over a century calculates the lye required from the saponification value of the fats and calculates the water required based on the lye amount. I think it's just one of those odd ideas, along with the idea of "water discounting", that come from the early days of modern handcrafted soap making.
The default in SoapCalc is to calculate the water based on oils, but you can also specify the lye solution concentration -- click on "Lye Concentration" right below "Water as % of Oils" and enter the NaOH concentration as a percentage. Stick with the method that makes the most sense to you, and you'll be good.
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Ok - so SoapCalc gives me the lye quantity, then i have to multiply this quantity by 2 to obtain the water quantity. Thanx again.
Yes, you're spot on correct. To get a 33% NaOH solution, you would multiply the NaOH weight by 2 to get the water weight.
If you are using SoapCalc, you don't have to hand calculate the water unless you want to.
When you get to Step 7 on the SoapCalc form, there is a button that says "1. Calculate Recipe" and a second button below that that says "2. View or Print Recipe".
If you click button 1 and then click button 2, the recipe that appears will give the correct water amount based on the lye concentration you entered at the top of the SoapCalc form.
If you are using SoapCalc, you don't have to hand calculate the water unless you want to.
When you get to Step 7 on the SoapCalc form, there is a button that says "1. Calculate Recipe" and a second button below that that says "2. View or Print Recipe".
If you click button 1 and then click button 2, the recipe that appears will give the correct water amount based on the lye concentration you entered at the top of the SoapCalc form.
SoapOfTheNorth
Active Member
I’m having trouble dissolving 2.5oz lye into 7oz water (distilled). The ratio is about 2.6 : 1 (water:lye). My house is very low humidity (24% today) and the room temp is 20deg/c.
For fun I put 1 oz lye into 12 oz water it still didn’t fully dissolve.
I keep my lye in a plastic storage bin in it’s original packaging. I have several of those humidity bags in there too to keep it dry, although I’ve noticed it’s starting to get a little clumpy (just a little). From past experience - lye can turn a little gray like dirty snow.. when it’s absorbed water from the air, and it doesn’t work as well when that happens. I’m not noticing this. It still soaps really well - I just don’t want any solid lye bits in my soaps. Any thoughts on this?
For fun I put 1 oz lye into 12 oz water it still didn’t fully dissolve.
I keep my lye in a plastic storage bin in it’s original packaging. I have several of those humidity bags in there too to keep it dry, although I’ve noticed it’s starting to get a little clumpy (just a little). From past experience - lye can turn a little gray like dirty snow.. when it’s absorbed water from the air, and it doesn’t work as well when that happens. I’m not noticing this. It still soaps really well - I just don’t want any solid lye bits in my soaps. Any thoughts on this?
It sounds to me like your lye has absorbed a bit of moisture. My experience with this in the past is that once it clumps/hardens like that, or fails to heat the water to 200F, then the lye isn't going to function as needed to make soap. But someone smarter about science than I am (probably 99% of those on this forum, hah!) may be able to offer a solution.
SoapOfTheNorth
Active Member
Yeah I was worried about that - I think I’ll get some new lye and see if it’s better - thanks
Lin19687
Well-Known Member
Please start a new thread, this one is from 2013
7a) "I recently came across a much older thread on the forum that contained some info that really helped me out, and so I responded to it with a 'thanks!'", or.....
7b ) "I recently came across a much older thread that left me curious about a few things, and so I posted to it in order to ask a question.", or....
7c) "I recently came accross a much older thread that inquired about a certain subject that I happen to know a little something about, and so I posted to it in order to contribute my 2-cents." .......
Why such negative responses to the above from some of our members?
In a word: necroposting (a combination of "necro" = dead, and posting), i.e., urban slang for posting to a thread that has been dead for some time.
If one does an internet search on necroposting, one will quickly discover that the practice is generally frowned upon and even outright banned on many forums, although there are some forums that tolerate it......up to a point. SMF does not have an official rule that outright bans necroposting (we tolerate it up to a certain point), but because it can oftentimes be a bone of contention amongst some of the more established members of our community, most especially when one's necrocropost is a rather frivolous one, and/or does not add any new, useful/helpful information to the discussion in old thread, we've put together some guidelines that will help you decide whether tis better to necropost and risk the potential ire of the community, or to refrain and just hit the 'Like" button instead, or to start an entirely new thread with a link pointing to the old thread:
-Guideline in regards to statement '7a' from above (necroposting to merely add a 'thanks'): Definitely not worth the ire. 'Tis much better to click on the 'Like' button than to necropost on an old thread just to say 'Thanks!" or "Cool idea!" or other such similar things that don't add anything useful to the discussion ........especially since many see this type of necroposting as nothing more than a ploy to boost one's post count.
-Guideline in regards to statement '7b' from above (necroposting to ask a question): More than likely not worth the ire. 'Tis much better to start a new thread in which to pose your question (with a link pointing to the old thread), than it is to necropost in the old thread, because new questions posed on old threads oftentimes fail to generate a response, especially if the original OP and/or respondents are no longer active on the board. Besides that, there's also a good chance that your question may fail to generate a response because new questions posed on old threads oftentimes get lost in the shuffle due to people mistaking the old thread for a brand new thread. What happens in that case is that the people who open up the thread (who mistakenly think that it is a new thread) will read only so far as the OP's question in post #1 and respond to that, without ever seeing your question that was posted further along, which will result in your question becoming buried in the mix where it is even harder to see.
Necroposting to ask a question can also cause a bit of troublesome confusion and possibly even danger for newer members depending on how old the thread is when the new question bumps the thread back up to the front page, because many of the old posts in the thread may contain outdated/abandoned advice no longer espoused by the original poster(s) to the thread, and/or practices no longer deemed necessary or safe...... but because the thread is back on the front page, it is often mistaken by newcomers as being a current thread filled with current, up-to-date good info and advice, when the very opposite may actually be the case.
Last but not least, there are a number of our members who have gone on record with the statement that they take a dim view of necroposting, and purposefully refuse to open threads that have been resurrected by a necropost.
-Guideline in regards to statement '7c' from above (necroposting to add a new bit of helpful wisdom): This is one of the times where a necropost might be worth the risk of attracting any potential ire, depending on the level of helpfulness, accuracy, and/or relevance of your words of wisdom. If you are ever in doubt, though, as to whether you should necropost your words of wisdom in the old thread, or rather introduce them in a new thread with a link pointing to the old thread, just let it be said that no one will ever fault you for doing the latter of the two.
7a) "I recently came across a much older thread on the forum that contained some info that really helped me out, and so I responded to it with a 'thanks!'", or.....
7b ) "I recently came across a much older thread that left me curious about a few things, and so I posted to it in order to ask a question.", or....
7c) "I recently came accross a much older thread that inquired about a certain subject that I happen to know a little something about, and so I posted to it in order to contribute my 2-cents." .......
Why such negative responses to the above from some of our members?
In a word: necroposting (a combination of "necro" = dead, and posting), i.e., urban slang for posting to a thread that has been dead for some time.
If one does an internet search on necroposting, one will quickly discover that the practice is generally frowned upon and even outright banned on many forums, although there are some forums that tolerate it......up to a point. SMF does not have an official rule that outright bans necroposting (we tolerate it up to a certain point), but because it can oftentimes be a bone of contention amongst some of the more established members of our community, most especially when one's necrocropost is a rather frivolous one, and/or does not add any new, useful/helpful information to the discussion in old thread, we've put together some guidelines that will help you decide whether tis better to necropost and risk the potential ire of the community, or to refrain and just hit the 'Like" button instead, or to start an entirely new thread with a link pointing to the old thread:
-Guideline in regards to statement '7a' from above (necroposting to merely add a 'thanks'): Definitely not worth the ire. 'Tis much better to click on the 'Like' button than to necropost on an old thread just to say 'Thanks!" or "Cool idea!" or other such similar things that don't add anything useful to the discussion ........especially since many see this type of necroposting as nothing more than a ploy to boost one's post count.
-Guideline in regards to statement '7b' from above (necroposting to ask a question): More than likely not worth the ire. 'Tis much better to start a new thread in which to pose your question (with a link pointing to the old thread), than it is to necropost in the old thread, because new questions posed on old threads oftentimes fail to generate a response, especially if the original OP and/or respondents are no longer active on the board. Besides that, there's also a good chance that your question may fail to generate a response because new questions posed on old threads oftentimes get lost in the shuffle due to people mistaking the old thread for a brand new thread. What happens in that case is that the people who open up the thread (who mistakenly think that it is a new thread) will read only so far as the OP's question in post #1 and respond to that, without ever seeing your question that was posted further along, which will result in your question becoming buried in the mix where it is even harder to see.
Necroposting to ask a question can also cause a bit of troublesome confusion and possibly even danger for newer members depending on how old the thread is when the new question bumps the thread back up to the front page, because many of the old posts in the thread may contain outdated/abandoned advice no longer espoused by the original poster(s) to the thread, and/or practices no longer deemed necessary or safe...... but because the thread is back on the front page, it is often mistaken by newcomers as being a current thread filled with current, up-to-date good info and advice, when the very opposite may actually be the case.
Last but not least, there are a number of our members who have gone on record with the statement that they take a dim view of necroposting, and purposefully refuse to open threads that have been resurrected by a necropost.
-Guideline in regards to statement '7c' from above (necroposting to add a new bit of helpful wisdom): This is one of the times where a necropost might be worth the risk of attracting any potential ire, depending on the level of helpfulness, accuracy, and/or relevance of your words of wisdom. If you are ever in doubt, though, as to whether you should necropost your words of wisdom in the old thread, or rather introduce them in a new thread with a link pointing to the old thread, just let it be said that no one will ever fault you for doing the latter of the two.
