For those of you that use a “Tank” cutter (or Tank style cutter that cuts one inch thick bars with a wire), what is the fully cured weight of your soap. I realize that there are other variables, my molds make soap that measure 3.5” wide by 2 3/8” tall. Thanks.
Tank Cutter - Cured Bar Weight
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Deda
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There are far too many variables to predict the exact weight of your soap.
Do you know the specific gravity of all your ingredients?
What is your expected percentage of evaporation? (this is partially based on your lye:water ratio)
Do you know the specific gravity of all your ingredients?
What is your expected percentage of evaporation? (this is partially based on your lye:water ratio)
I use the WSP green silicone molds and use the hobby version of the Tank (wood base, but aluminum handle - I chose this version because my loaves are only 8 inches and I liked that the cutter lays flat when not in use and can be 'hung' on the wall) - my bars are pretty consistently 5 oz after cure with a 36% water discount. I love my cutter - and the little 'twang' at the end of each cut makes my day 
I also use the WSP green silicone molds. I use 28 oz. of oil per batch and most often a 33% lye solution. My loafs usually weigh 38 - 41 ounces right out of the mold. I would estimate a 15 -18% evaporation rate. The loafs are not quite 8” long, they are short of this by about 1 – 2/16” of an inch. I was thinking I would only get 7 bars per batch with a Tank cutter, maybe 4.0 - 4.2 oz. each fully cured. Bukawww, do you end up with 7 or 8 bars? That satisfying little twang sounds like something I’ll have to have!!
Well I suppose if exact measurements are super important to you, you can only achieve 7 full bars from the WSP mold. I, personally would not sell the end pieces anyway, since they have a different appearance from the rest of the cut bars (smoothe on one side and almost always a bit mishapen from the slight bowing caused by moving the mold before its set up, etc) - I save those for test bars, personal use, freebies, and gifts.
I also work with 28oz of oils per mold @ 36% as I said however I almost always have overflow that I pour into cupcake molds...I fill to the very brim when possible and still have 5oz bars after 6 weeks of cure time.
The 'twang' is amazing lol.
I also work with 28oz of oils per mold @ 36% as I said however I almost always have overflow that I pour into cupcake molds...I fill to the very brim when possible and still have 5oz bars after 6 weeks of cure time.
The 'twang' is amazing lol.
I sell end pieces - they don't look significantly different from the "inside" bars - but that's just me.
Anyway, I've gotta go with the "it depends" response. On what are you basing your "15-18% evaporation" rate - and what precisely do you mean by that? Total weight loss of 15-18%? You should be able to calculate your bar weight yourself since you have the numbers.
Anyway, I've gotta go with the "it depends" response. On what are you basing your "15-18% evaporation" rate - and what precisely do you mean by that? Total weight loss of 15-18%? You should be able to calculate your bar weight yourself since you have the numbers.
I have to admit that I’m obsessing just a bit (yet again) about the little things. Soap making does that to me sometimes. Bukawww, thank you for the information you have shared – it has given me the push I needed to go ahead and order the cutter. I don’t make that much soap, but I like to make it look as good as I can.
By evaporation rate I do mean total weight loss. In other words if a start out with a 40 oz. loaf, once the bars are cut and fully cured, I’ll end up with about 33-34 oz. of soap. Deda’s post prompted me to come up with my evaporation estimate. I can make a pretty good calculation based on this. All I have to do is factor in the percentage of the loaf I may lose … no wait – I‘m obsessing again!
By evaporation rate I do mean total weight loss. In other words if a start out with a 40 oz. loaf, once the bars are cut and fully cured, I’ll end up with about 33-34 oz. of soap. Deda’s post prompted me to come up with my evaporation estimate. I can make a pretty good calculation based on this. All I have to do is factor in the percentage of the loaf I may lose … no wait – I‘m obsessing again!
