How NOT to measure your molds

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cinnamaldehyde

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I'd like to preface this by saying that I'm a former high school science and math teacher...

I like to measure my oils and NaOH in metric. So I thought to myself: "self, why don't you measure your molds in metric to get the mass of oils required that way, instead of mucking around converting ounces back to grams?"

So I went about my merry way, thinking of all the calculations I'll save myself. My 12" x 4" x 4" mold becomes a 30.48cm x 10.16cm x 10.16cm mold.

Are you laughing yet?

My mold, according to me, in metric, should require 1258.5__ of oil. I was a bit fuzzy on the units after multiplying the volume by 0.4. I decided it must be grams. I need 1258.5g of oil.

According to most normal people's calculations, using a factor of 0.4, my 12" x 4" x 4" mold needs 78.4oz of oils.

I make my recipe using 1258g of oil. I go to pour into the mold and my mold is only halfway full. I think to myself: "self, this doesn't seem right."

You can laugh now.

Turns out, 1258g does not equal 78.4oz. I was roughly 34oz short.

I now have little 2" high beer soaps.

(In all seriousness, this could have been quite bad if I'd measured the NaOH correctly and the oils incorrectly. But I input the oils into soapcalc, so my NaOH was correct for the amount of oils).

Lesson learned: the imperial system works?...?!...
 

Rowan

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This made me laugh so much, especially the little soaps! it's just the sort of thing I've done too, except I ended up with soaps so big, they barely fit into my hands!
 

newbie

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I suppose you already cut but otherwise you could have cut on the horizontal and had some 1 inch thick bars. Maybe. I'm an imperialist myself so I felt justified in my old fashioned way after reading about your soaps!
 

ngian

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Well I have developed an excel file that converts the grams that soapcalc shows for a recipe (oils-water-NaOH), to total ml.

I've used an average value of 1.09 for the specific weight of oils (values range from 1.09 to 1.1 among various oils) and calculate the liquid form of NaOH that has a volume a little more than its half weight when being in anhydrous form.

It also calculates the total metric capacity of a rectangular and cylindrical mold (ml), while it also shows the vertical height that the soap loaf will have in these molds with the specific recipe.

It seems to be working for me quite well.

https://www.dropbox.com/s/6ckxe5fte791ufd/CalculateMold-cm2ml_en.xls?dl=0

ETA:
If I'm calculating something wrong please correct me
 
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dixiedragon

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So...much...math...*brain splosion"

I work in an industry that uses small measurements a lot. Every time I have to use the measurement .0156 (1/64 inch) I so wish we used metric.

I think we need to make a world wide compromise that the all countries using the Imperial system will switch to metric, and all countries that drive on the left with drive on the right.
 

snappyllama

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So...much...math...*brain splosion"

I work in an industry that uses small measurements a lot. Every time I have to use the measurement .0156 (1/64 inch) I so wish we used metric.

I think we need to make a world wide compromise that the all countries using the Imperial system will switch to metric, and all countries that drive on the left with drive on the right.
That seems totally reasonable. Except I'm not giving up miles. Kilometers just sound silly. Would mpg become kpl? That's just goofy.

Besides, America gets to make the car rules. Because: 'Murica. :D
 

dixiedragon

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I got curious and Googled about why some drive on the left and some drive on the right. Apparently, originally all of Europe drove/rode on the left b/c knights rode their horses on the left because most of them were right handed. So you wanted to be able to hit your fellow travelers with a sword. In the 1800s or so, the Americans and the French started riding on the right, because teamsters (guys driving large wagons pulled by teams of horses) mounted their wagons from the left side and sat on the left side...I assume b/c most of them were right handed so they used their dominant arm to pull themselves into the wagon seat? Well, since those uppity rebels and the French were doing it, obviously the English would have no part of it. So basically, almost all places that drive on the left are former British colonies.
 

cinnamaldehyde

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Except I'm not giving up miles. Kilometers just sound silly. Would mpg become kpl?
MPG does not, in fact become KPL. In an instance where metric makes absolutely no sense, we measure fuel economy (at least in Canada) in L per 100km. So absolutely impossible to convert easily in your head.

Interestingly, I can estimate a pound easily, but not a kilogram (unless I do mental math). But I like kilometers when driving, inches and feet when measuring, but grams for small measurements. For cooking I measure in cups, teaspoons, and tablespoons, not mL. Unless I'm baking then it's back to grams. I know what an acre of land looks like, but have no idea what a hectare is. Oh and since I grew up on a farm and the legal land system in Canada is based on miles, I know that 1 mile x 1 mile is a section of land.

Whew. I'm exhausting myself. No wonder I multiplied by 0.4 and got grams :D
 

dixiedragon

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MPG does not, in fact become KPL. In an instance where metric makes absolutely no sense, we measure fuel economy (at least in Canada) in L per 100km. So absolutely impossible to convert easily in your head.

Interestingly, I can estimate a pound easily, but not a kilogram (unless I do mental math). But I like kilometers when driving, inches and feet when measuring, but grams for small measurements. For cooking I measure in cups, teaspoons, and tablespoons, not mL. Unless I'm baking then it's back to grams. I know what an acre of land looks like, but have no idea what a hectare is. Oh and since I grew up on a farm and the legal land system in Canada is based on miles, I know that 1 mile x 1 mile is a section of land.

Whew. I'm exhausting myself. No wonder I multiplied by 0.4 and got grams :D
More brain splosion.

My family and I visited Australia. (We're in the US.) We decided to take a horse back ride. Mom calls to ask if there is a weight limit, b/c Dad is pretty fat. (Dad was all butthurt about this.) She tells the lady who owns the stable how much Dad weighs...in pounds. The lady asks how many kilos that is? Well, we have no idea. And none of us knew the conversion. Then the lady says, "Well, how many stones?" We have NO idea what that is at all! So this lady could convert from kilos to stones, but not pounds.
 

TeresaT

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Oh man I'm sorry I had to laugh at this. You now have teapot beer soap... they're short and stout! Hehehehehe
I bellowed at that!! That's one of my favorite nursery rhymes and I love teaching that to my nieces and nephews! (Along with the "Barrels of beer" song. It's always cute to hear a bunch of pre-schoolers shouting out "take one down and pass it around...")

BTW: I can totally appreciate the numerical mix up.
 
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