I used a different mold than I'm used to, making soap with a friend. I'm not a happy mathematician, that's sure. I used the formula in the 'oil for mold' thread - length times width times height of pour times .40. The mold was 10 x 16 x a 2.5 inch pour. I got 160 ounces. That was WAY too much. What did I do wrong? That same formula has worked like a charm for me before.
Measuring for my mold - what did I do wrong?
- Thread starter MoonBath
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I get the same results you did, and just did it for my mold and it worked.
Are you really using a 10 x 16 inch slab mold? If so this makes sense, that's a decent size slab. Was your intention to pour to 2.5 inches deep?
Are you really using a 10 x 16 inch slab mold? If so this makes sense, that's a decent size slab. Was your intention to pour to 2.5 inches deep?
It's not a slab mold, really. It was just a tupperware thing she wanted to use. It's 3 inches tall, so I wanted to do a 2.5 in. pour.
I have no idea what I did wrong. I did that equation over and over because it seemed like so much; I measured carefully. I had quite a bit left over.
FlybyStardancer
Well-Known Member
Did you add anything besides the oils/liquids/lye?
For the mold... Are the sides straight or sloped? The corners curved? Did you measure from the outside of the top lip, or the inside of the mold?
For the mold... Are the sides straight or sloped? The corners curved? Did you measure from the outside of the top lip, or the inside of the mold?
I used less than the Maple Springs soap calculator said to use; they said about 59 oz. to 21.something oz. of lye.
I added 7 oz. of fragrance, as per Maple Springs. The sides of the mold are straight; the corners are curved. The mold itself is thin plastic, not much difference between the outside and inside of the lip. My friend did the measuring, but it was definitely correct.
When you entered your numbers into the lye calculator, are you sure you didn't enter the total batch weight instead of the total oil weight? I recently made that mistake and ended up with a 7 pound batch instead of 5 pounds.
I just entered the amount of each oil in ounces.
Turning it in to CMs and grams, we get to 4200grams, which is about 300 grams off from 160 ounces - that's not a small amount.................
Ok. This is really baffling me. The first few times I used this formula it worked precisely. Now the numbers I'm getting are WAY off. The Freshware silicone loaf mold I use is a little over 12 inches by a little over 5 inches by 2.5 inches deep. The first time I used that formula, the answer I got, somehow, was 34.4 oz. It works perfectly. Now, when I use what I think is the same formula, I get over 52 oz, which is WAY too much. I have no idea what's going on.
Ok. Now I'm REALLY confused. I found an online calculator that says to multiply by .38 instead of .40. I used it with the dimensions of my mold and it says to use 47.29 oz. of oils, when I KNOW from having used it before that that's way too much. I have no idea why this is happening. I know it must be something I'm doing, and it's probably something simple. I just don't know what.
Kansas Farm Girl
Well-Known Member
MoonBath, when you say the 160 oz of oil was way too much do you mean too much oil or too much soap batter after you mixed your oils, water, lye and any other additives together?
Somewhere there is an error and my money goes to measurement of the oils. Easily done if there is any distraction. Numbers transposed?
The calculations are correct. The calculator can only give the answer based on data entered. The only other possibility would be incorrect measurement of the mold.
Start from scratch, measure again, calculate, weigh oils and double check amounts before checking off.
"I've cut this board twice and it's still too short!" :crazy:
The calculations are correct. The calculator can only give the answer based on data entered. The only other possibility would be incorrect measurement of the mold.
Start from scratch, measure again, calculate, weigh oils and double check amounts before checking off.
"I've cut this board twice and it's still too short!" :crazy:
Too much batter.
It's definitely not that. For some reason, the formula I used before, which I got from the 'oil for mold' thread, gave me 34.4 oz. for the Freshware mold. I've used that for several batches with the water amounts I get when I run the recipe through the Maple Springs calculator, and it's perfect. Now when I use that formula, which I swear is the same one, with that mold's measurements, I get MUCH more than 34.4, which I know works perfectly for that mold.
This last time, with my friend's mold, I made sure the measurements were right, ran the equation as written (l x w x h x .40) and got too much batter - and so much oil that I could tell before I ever mixed it with lye that it was going to be too much.
No, that's definitely not it... :think:
Kansas Farm Girl
Well-Known Member
I have seen a difference based on water content in the soap batter. My batch size matches my expected total oz if I use the water listed in the “Water as a % of Oils” in SoapCalc. But if I change from the 38% that appears to be the default there then I either have a larger or smaller batch.
I played with all my molds and determined that the total volume (L*W*H)* .6 gives a pretty close estimate of the total volume of soap batter the mold will hold, if you use the 38% Water to Oils from SoapCalc. MoonBath’s 10x16x2.5 mold has a total volume of 400 square inches * .6 = 240 oz. This size mold should use 160 oz of oil, 20.6 oz lye and 60.8 oz water of soap batter before cure of 241.4 as calculated by SoapCalc. Sometimes I use less water and my batches don’t fill the molds quite as much as I had thought they would. I had never looked into it before to see exactly why, but once I started playing with what I have been doing I see that I reduce my overall batch size by 6% by cutting the amount of water I use. Take a look at your total batter weight and see if you ended up making more than about 240 oz of batter.
I played with all my molds and determined that the total volume (L*W*H)* .6 gives a pretty close estimate of the total volume of soap batter the mold will hold, if you use the 38% Water to Oils from SoapCalc. MoonBath’s 10x16x2.5 mold has a total volume of 400 square inches * .6 = 240 oz. This size mold should use 160 oz of oil, 20.6 oz lye and 60.8 oz water of soap batter before cure of 241.4 as calculated by SoapCalc. Sometimes I use less water and my batches don’t fill the molds quite as much as I had thought they would. I had never looked into it before to see exactly why, but once I started playing with what I have been doing I see that I reduce my overall batch size by 6% by cutting the amount of water I use. Take a look at your total batter weight and see if you ended up making more than about 240 oz of batter.
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What did you use to measure the mold? Same measuring tool you always use? Someone else's? If not your normal tool, look closely at the scale. SAE? Metric? I'm grasping here because everything else has been shot down and it just doesn't add up. No pun intended. Last suggestion - try a different calculator.
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