Mold calculations

[Zoeybean]

Has anyone made a mold using Length of mold x Width of mold x Height of mold x .40 =oil weight and if so how accurate was it?
Also how would you calculate size of mold according to a soap recipe?
I did make a hinged mold today it is 36 length x 3.5 width x 2 high but have no clue if there is a standard to go by, dial soap bar measures 2x3.5 so that's what I went by...
Do you think it makes a difference which way the mold is 2"H x 3.5"W or 3.5"H x 2"W ? I thought wider might work better for swirls and such.
What size bars do you make?

 

[wetshavingproducts]

Depends on the amount of additives. If zero additives, I'd imagine it's pretty accurate. With lots of additives, not at all accurate.

 

[IrishLass]

Ditto what Lee said.

I've never made a mold, but I do use that equation to help me figure out how big of a batch I can make as per weight of oils whenever using a new mold (or buying one), and it works amazingly well.

My favorite soap size is 3.5" wide by 2.5" tall and 1.25" thick, and one of my favorite log molds to use that will give me those results has these dimensions: 3.5" wide, 3.5" tall, and 10" long (gives me 8 perfect bars). I don't fill the mold up all the way to the top, but just enough to give me 2.5" in height. I like that it's 3.5" tall, though, because it gives me extra head space so that when I want to use additives, my soap doesn't overflow the top of the mold.


IrishLass

 

[Zoeybean]

Ditto what Lee said.

I've never made a mold, but I do use that equation to help me figure out how big of a batch I can make as per weight of oils whenever using a new mold (or buying one), and it works amazingly well.

My favorite soap size is 3.5" wide by 2.5" tall and 1.25" thick, and one of my favorite log molds to use that will give me those results has these dimensions: 3.5" wide, 3.5" tall, and 10" long (gives me 8 perfect bars). I don't fill the mold up all the way to the top, but just enough to give me 2.5" in height. I like that it's 3.5" tall, though, because it gives me extra head space so that when I want to use additives, my soap doesn't overflow the top of the mold.


IrishLass

Thanks Lee and IrishLass I appreciate your input, after making my mold it does look a little shallow and I don't want my bars of soap to look wimpy. when I made my mold I started with 3" sides then thought I better make them 2" so the soap would be level with the top - Watching soap videos it looks like most are filled to the brim I should have left it alone, my OCD won't let me do that :roll: today I shall make another mold...Thanks again, Zoe

 

[Zoeybean]

the calculations are spot on...today I tested it and used 12
inches of my 36 inch mold and it was perfect...

 

[goji_fries]

The calculations work for cylindrical molds too. Just did it right now, perfect.

(pi x radius x radius x height) x .40) = base oil weight

 

[lionprincess00]

I did salt bars. Like the post above, cylinders are pi (3.14) x radius squared x height or
3.14x RxRxH (edit, this is for total volume...then x .40 for oil wt. Gah, am I dreaming, is this a high school nightmare again....ahhhhhhh!!!!!!!!!)

I also do the l x w x h x .40 for rectangular or square volume.

Since I did do salt bars, the soap calc didn't take the 100% salt wt of oil wt into account, so multiplying 6 cylindrical molds volume with the 40% oils was more than I needed in the end after the salt addition, and I poured off the extra into my tiny loaf mold. Point is, the 40% of l x w x h works awesome, unless, as the prior posters state, you have additives adding to the overall volume.



Lovely soap there btw !!!