Citric acid as a chelator
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Is this for 90% KOH? Also, when do I add the CA? Would dissolving it straight in the KOH/water solution (pre-oil merge) be a problem?
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Good question! This relationship isn't based on 90% KOH, because I have no idea what purity a person is using -- it can range from 85% to 95%. If you want to do the correction, here's how:
KOH weight adjusted for actual purity = (KOH weight based on 100% purity) * 100 / (Actual KOH purity)
Here's an example of how to use this formula:
Actual KOH purity = 92%
KOH weight based on 100% purity = 52 grams
KOH weight adjusted for actual purity = 52 * 100 / 92 = 55.4 grams
KOH weight adjusted for actual purity = (KOH weight based on 100% purity) * 100 / (Actual KOH purity)
Here's an example of how to use this formula:
Actual KOH purity = 92%
KOH weight based on 100% purity = 52 grams
KOH weight adjusted for actual purity = 52 * 100 / 92 = 55.4 grams
It says:
While for example 3% of 1000g is indeed 30g, 3% ppo (Per Pound of Oil?) is 13.6 grams.
Which is it
?Very good info in those articles, just a bit confused on that little tidbit.
It says:
While for example 3% of 1000g is indeed 30g, 3% ppo (Per Pound of Oil?) is 13.6 grams.
Which is it
Very good info in those articles, just a bit confused on that little tidbit.
Both actually.
If you are weighing your oils in grams, then a 1000 gram batch of oils will need 30 grams (1.07 oz). Which is 3% weight of oils.
If you are weighting your oils in pounds, then a 32 oz batch of oils will need .96 oz (26.88 grams). Which is 3% weight of oils.
Since one ounce equals roughly 28 grams, the 1000 gram batch of oils is slightly more than two pounds of oils, which accounts for the slightly higher amount of CA.
So, the moral of the story is stick to a unit of measurement; don't mix grams and ounces. Even though I am an American and the imperial system for "real life" situations, I only soap in grams. I also don't take the "ppo" literally. Personally, I view it as "per weight oils" which encompasses metric and imperial units. It's the number before the abbreviation that you need to concentrate on. Also, make sure it is supposed to be in relation to the weight of the oils (only) and not the entire batch (which includes your lye solution and all of your additives).
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Well this is embarassing. No idea what the heck I was thinking, lol. Now that I see it, my question basically: "What is heavier, a pound of feathers or a pound of bricks?"...
Thanks for the reply, and sorry about the confusion. For some reason I was expecting a linear relation between 30g of used CA and completely unrelated measuring units to happen.
:mrgreen:
Thanks for the reply, and sorry about the confusion. For some reason I was expecting a linear relation between 30g of used CA and completely unrelated measuring units to happen.
:mrgreen:
No worries! That got me stuck for the longest while, which is why I strictly soap in grams. Sometimes I'd figure something to be 1.0587 oz and for some reason, my scale will not go to 1.06 oz. I'll go from 1.05 to 1.07, but never hit 1.06. I found this extremely frustrating, so I switched to grams and ignored the decimal places. My scale easily goes to whole number grams and doesn't skip anything. The thing I have trouble with is when instructions for FOs state .5 oz or 1 oz ppo. In addition, many FOs are sold in volume, not weight, so that's a factor, too. I prefer it in percentages because it is much easier for me to convert. But I am the queen of bad math. If I can figure it out, anyone can!!
"... I also don't take the "ppo" literally. Personally, I view it as "per weight oils" which encompasses metric and imperial units...."
Exactly! Good explanation, T!!! For someone who says she "sux at math" you have a good intuitive understanding of it.
Exactly! Good explanation, T!!! For someone who says she "sux at math" you have a good intuitive understanding of it.
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Maybe instead of "ppo" we should say "bwoo" or "bwo" meaning "by weight of oils". I always work only in grams like Teresa, so I have to translate the meaning of ppo like she does. I'm afraid tradition might get in the way of this change, but it's worth a thought....
Or "pow" - Percent of Oil Weight.
ngian
Well-Known Member
I vote for POW!! Instead of 3% ppo it would be 3 pow. Totally works for me.
How much oatmeal POW did you use?
Made 3 batches simultaneously, one 3% SF, one 0% SF and one 3% SF with 3% POW CA (as a chelating agent).
The CA batch had a noticably delayed time to paste, compared to the other two. I'm thinking the CA hogs the hydroxide for a while, especially with the subpar mixing I was able to achieve*, leaving the oils sad and lonely for a while - resulting in longer time needed.
*Paste prep inside quart jars, inside 23QT pot. The only way I could think of, to do 3 different batches at the same time. Mixing is predictably harder.
The CA batch had a noticably delayed time to paste, compared to the other two. I'm thinking the CA hogs the hydroxide for a while, especially with the subpar mixing I was able to achieve*, leaving the oils sad and lonely for a while - resulting in longer time needed.
*Paste prep inside quart jars, inside 23QT pot. The only way I could think of, to do 3 different batches at the same time. Mixing is predictably harder.
CA hogs the hydroxide forever, more or less. It reacts with KOH to make potassium citrate, leaving less to react with the oils and thus increasing the SF. Maybe that would slow down the TTP (time-to- paste) also.
I suppose it would've been prudent to mention in my post above, that I added the appropriate amount of extra KOH (adjusted for actual purity - 5.6g KOH for the 6g CA used), so that SF isn't increased. Theoretically anyway.
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