How to figure how much oil for mold.

Discussion in 'Lye-Based Soap Forum' started by Soapmaker Man, Mar 26, 2008.

Help Support Soapmaking Forum by donating:

  1. Aug 17, 2013 #121

    bodhi

    bodhi

    bodhi

    Well-Known Member

    Joined:
    Apr 2, 2013
    Messages:
    547
    Likes Received:
    228
    Exactly! Except math isnt my strong suit so i figured, 'hey cant hurt to try it anyway'. Yeah. I was scurrying for molds mid pour. When i actually sat down to figure it out i got as far as the water concentrations and stopped because i couldnt deal with trying to figure the calculations. Now I see why, lol.

    And bravo Sososo! Kowtow, kowtow.
     
  2. Aug 19, 2013 #122

    sososo

    sososo

    sososo

    Well-Known Member

    Joined:
    Jun 17, 2013
    Messages:
    136
    Likes Received:
    37
    Not very complicated. I'm happy that this calculations will help somebody.
     
  3. Aug 19, 2013 #123

    Hazel

    Hazel

    Hazel

    Lifetime Supporter

    Joined:
    Feb 1, 2009
    Messages:
    12,667
    Likes Received:
    1,838
    Location:
    Ohio
    Thanks everyone! I've merged this topic with the sticky "How to figure how much oil for mold" since it is related to the thread and made a permanent redirect to it.
     
  4. Sep 28, 2013 #124

    BrambleNBumble

    BrambleNBumble

    BrambleNBumble

    Well-Known Member

    Joined:
    Sep 9, 2013
    Messages:
    91
    Likes Received:
    37
    Location:
    West Des Moines, Iowa
    Newbie here and I'm still confused on how to figure out how much oil to use for a mold. I bought a three pound mold but all the recipes I'm finding are for five pounds or higher. Is there an easy way to figure this out or is it more trial and error?
     
  5. Sep 28, 2013 #125

    alaskazimm

    alaskazimm

    alaskazimm

    Well-Known Member

    Joined:
    Jul 29, 2013
    Messages:
    83
    Likes Received:
    40
    Location:
    Western Alaska
    Easiest way I've found is to use the formula in the first post to find the weight of oils for your mold. Then convert the weights of the oils to % of recipe and run that through a lye calculator of choice. Example: For a 3 oil basic bar the posted recipe

    Coconut Oil 270 gr
    Olive Oil 360 gr
    Palm Oil 270 gr

    Convert that to % of recipe and you get

    Coconut 30%
    Olive 40%
    Palm 30%

    My small mold takes 695 gr of oil so plugging all that into my lye calculator comes out with

    Coconut 209 gr
    Olive 278 gr
    Palm 209 gr

    hope that helps.
     
  6. Oct 5, 2013 #126

    gruntedsoaps

    gruntedsoaps

    gruntedsoaps

    Well-Known Member

    Joined:
    Sep 3, 2013
    Messages:
    46
    Likes Received:
    2

    I have never moved so fast for a muffin pan ever in my life. lol. Im new so I tried it blindly. I WAS WAY OFF. were talking it filled my loaf pan and a muffin pan. and they were all filled to the top, the loaf pan actually has a mountain on it. lol. whatever it worked and I got all the soap I could.
     
  7. Oct 27, 2013 #127

    A1will

    A1will

    A1will

    Active Member

    Joined:
    Oct 16, 2013
    Messages:
    38
    Likes Received:
    4
    Post for future. Reference
     
  8. Nov 6, 2013 #128

    G Str

    G Str

    G Str

    New Member

    Joined:
    Nov 6, 2013
    Messages:
    4
    Likes Received:
    1
    I'm not sure if this has been pointed out so far, but the 0.40 thing works only for imperial; inches and ounces.
    If you use metric, grams and centimeters you must use about 0.70.

    Proof:
    say you want to fill a mold with dimensions of 2x3x4 (in inches). The volume is 24 cubic inches. You do the 0.4 thing and get 9.6 oz of oils.
    now try that in cm. 1 in = 2.54 cm, so the dimensions of mold will be 5.08x7.62x10.16 in cm. That's a volume of 393.29 cubic centimeters. Do the 0.4 thing and you get a number of 157.32. What's that? Grams? Let's check. 1 oz. = 28.35 grams. 157.32/28.35 = 5.55 oz. You're 4.05 oz. short. Now try it with 0.7. 393.29x0.7 = 275.3, convert to oz. and you get 9.7 oz of oils. Now that's more spot on.
    Where I'd get 0.7? From sososo's calculations, the same way he proved the 0.4 thing.

    So long story short, it's 0.4 for ounces and inches, 0.7 for grams and centimeters.
     
    justrambling likes this.
  9. Nov 25, 2013 #129

    The Efficacious Gentleman

    The Efficacious Gentleman

    The Efficacious Gentleman

    Lifetime Supporter

    Joined:
    Nov 19, 2013
    Messages:
    8,929
    Likes Received:
    8,891
    Location:
    Austria
    Not sure if it's already been covered, but for those that struggle with maths, you can use the formula for calculating how big the mold needs to be depending on the size of your batch -

    Let's say I have a 7x5x2 inch mold - that's 7x5x2x0.4 to work out the oz of oils = 28 oz.

    But I'm making a new mold (will swap to metric as that is what I'll be working in) and I want to make a 550gm batch 8cm wide, 5cm deep. To work out how long my mold would be is 550/0.7 (for metric!) /5/8 = 19.64cm long. Oils/0.7/height/width.

    Now 19.64 is a pain to get and wouldn't give me regular sized soaps, so I can work out the depth I'd get if I made it 20cm long - Oils/0.7/width/length = depth. 550/0.7/8/20 = 4.9cm deep.
     
    DePoort likes this.
  10. Nov 25, 2013 #130

    MoonBath

    MoonBath

    MoonBath

    Well-Known Member

    Joined:
    Nov 13, 2013
    Messages:
    194
    Likes Received:
    53
    Location:
    Colorado
    :Kitten Love: I'm not a math person at all. So, this is probably a stunningly stupid question, but how does this solve for the space the water takes up? :confused:
     
    Jenn2980 likes this.
  11. Dec 1, 2013 #131

    tryanything

    tryanything

    tryanything

    Well-Known Member

    Joined:
    Sep 2, 2010
    Messages:
    301
    Likes Received:
    59
    Location:
    Cleveland Ohio
    It's magic! Seriously, just go with it. It works. I'm no math person either but I've successfully used this formula for many different mold shapes. Maybe someone else will chime in with a more technical answer.
     
  12. Feb 3, 2014 #132

    brigettevelasquez

    brigettevelasquez

    brigettevelasquez

    Member

    Joined:
    Feb 1, 2014
    Messages:
    20
    Likes Received:
    5
    Hi soap makers! Im a new soap maker and new in SMF as well. I have this homemade wood loaf mold and i was able to figure out how much oil to use by weighing the mold and then i press tare on my weighing scale and pour in rice grains inside. ImageUploadedBySoap Making1391414335.053583.jpg
     
  13. Feb 3, 2014 #133

    new12soap

    new12soap

    new12soap

    Well-Known Member

    Joined:
    Apr 13, 2012
    Messages:
    1,671
    Likes Received:
    945
    It doesn't exactly solve for it, but it does take it into account. The volume of water in 1 cubic inch is 0.55 ounces. The same volume of oil will weigh less than that because oil is less dense than water (that's why when you mix oil and water, say in your salad dressing, the oil will float on top). Using 0.4 ounces of oil (by weight which is how we measure when making soap) per cubic inch of mold space, that allows for the addition of water and lye.

    Remember, we are converting volume measurements to weight. This is a very simple formula that allows for using FULL water, and then the user can adjust for water discounts or additives.

    It does work!
     
  14. Feb 3, 2014 #134

    The Efficacious Gentleman

    The Efficacious Gentleman

    The Efficacious Gentleman

    Lifetime Supporter

    Joined:
    Nov 19, 2013
    Messages:
    8,929
    Likes Received:
    8,891
    Location:
    Austria
    Have you done the calculation too, to see if they marry up?
     
  15. Feb 3, 2014 #135

    brigettevelasquez

    brigettevelasquez

    brigettevelasquez

    Member

    Joined:
    Feb 1, 2014
    Messages:
    20
    Likes Received:
    5
    Yes i computed using soapcalc. So if my total oil weight is 500g + 35% of water the soap mixture will fit my mold :)
     
  16. Feb 3, 2014 #136

    The Efficacious Gentleman

    The Efficacious Gentleman

    The Efficacious Gentleman

    Lifetime Supporter

    Joined:
    Nov 19, 2013
    Messages:
    8,929
    Likes Received:
    8,891
    Location:
    Austria
    How does that compare with the w x h x l x 0.7 calculation on the mold space?
     
  17. Feb 3, 2014 #137

    brigettevelasquez

    brigettevelasquez

    brigettevelasquez

    Member

    Joined:
    Feb 1, 2014
    Messages:
    20
    Likes Received:
    5
    Rice grain weight = 700g

    So if your water percentage is 35%

    700g * 0.35 = 245g (water weight)

    700g - 245g = 455g (oil weight)

    :) haven't tried the formula WxLxH x 0.7 but will try it soon :)
     
  18. Feb 3, 2014 #138

    The Efficacious Gentleman

    The Efficacious Gentleman

    The Efficacious Gentleman

    Lifetime Supporter

    Joined:
    Nov 19, 2013
    Messages:
    8,929
    Likes Received:
    8,891
    Location:
    Austria
    Please do! I'm interested to find out more about your measurements................... :grin:
     
  19. Feb 3, 2014 #139

    brigettevelasquez

    brigettevelasquez

    brigettevelasquez

    Member

    Joined:
    Feb 1, 2014
    Messages:
    20
    Likes Received:
    5
    I use this same method in making silicon mold so i can figure out how much silicon rubber to use for my mold. And i tried it on my first batch of soap and it worked!
     
  20. Feb 3, 2014 #140

    Saponista

    Saponista

    Saponista

    Well-Known Member

    Joined:
    Dec 16, 2013
    Messages:
    2,116
    Likes Received:
    1,313
    Location:
    Plymouth, Devon, UK
    Wxlxh x0.7 worked like a dream for me
     

Share This Page