08-02-2012, 06:40 PM
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This was a post I orginally posted on another site, hopefully its ok to repost here as its a little experiment I'd like to continue in the not too distant future....

Here is a real quick and dirty experiment I thought I would try out. I wondered if there was a way to really see how much soap is used when building a lather. After a while I thought of using weight as measure.

So, as my daughter was having her bath time with SWMBO, I thought I'd run downstairs and take a few pics.

So here we go, here is my tub of TFS on the scale. As you can see, after a few uses it weighs .076kg.
[Image: b91a3e67.jpg]

For the first round I'd thought I would use a Golden Nib Super as a generic badger brush.
[Image: db24c23e.jpg]

Here we are all loaded up. I usually swirl the brush roughly 30 seconds or so without shaking too much water out before hand.
[Image: ea6cbe0d.jpg]

So with that done, I rinsed off the soap, dried off the tub and dabbed a little paper on the soap to get any excess water off and weighed the tub.

[Image: 1ef7da96.jpg]
As you can see, the tub now weighs .075kg.

Next up, I chose my fav boar, the Omega 49. Here it is after a good soak and letting some of the water drain. Again, I don't flick off too much water and let the bubbles fly.
[Image: d9e273f2.jpg]

And with that, I swirled for about 40 seconds. The Omega 49 can hold a lot of water and takes a little longer for the bubbles to settle down and thicken up.
[Image: 26e6f27b-1.jpg]

After being done lathering up I did the same clean up job of rinsing off the soap, drying off the tub and dabbing the wet soap with a paper towel.

The pic here shows that the tub now weighs .074kg.
[Image: 510f1cb3-1.jpg]

I will point out that the scale was teetering on showing .073kg.

So what has this shown us? Probably brought up more questions than answers, such as; Does a badger use the same amount of soap as a boar? Would the results be different if the knots were different sizes? Should we swirl the brush for a certain amount of seconds or until the lather is a specific consistency?

Well, my curiosity was piqued so I thought I would see what the results would be. To be more conclusive, many more trial runs with the same equipment and different equipment would have to happen to get a better understanding of how much soap is used to build a lather/load a brush.

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 08-02-2012, 06:48 PM
#2
  • freddy
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  • San Diego, California, U.S.A.
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That's an interesting experiment, Gary. I hope you will be following up on it. I wonder, if used every day until finished, if the tub of TFS would be gone in 76 days or if the factors you mentioned, as well as others (such as the changing shape of the bowl), would come into play.

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 08-02-2012, 08:27 PM
#3
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Fascinating experiment. Thanks.

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 08-02-2012, 08:38 PM
#4
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My puck of Tabac lasted over a year. And I tried really really hard to use it up.

By my calculation, at that pace, whatever's left of that puck will be gone in less than 3 months.

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 08-02-2012, 09:29 PM
#5
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That's a very difficult thing to do, what you've done. Because how much water weight from the weight brush was imparted to the soap?

To get around that I started to keep track of the starting weight of the soap and keep track of the number of shaves. But to do that one must tally each shave. I failed.

Your method holds far more promise. Keep track and average over time and you should be able to project how many shaves it will yield.

Well done!

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 08-02-2012, 11:02 PM
#6
  • Persius
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  • Reading, England
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If you are at the extremity of the resolution of your measuring device (in this case 0.001 kg I assume) then any measurement is inherently inaccurate. The way the get around this, and to avoid differences in *experimenter error*, you should follow SD's advice and see how many uses it takes to use up an entire pot, or repeat your experiment a multiple of times and average the weight loss over that number of uses. Otherwise what you might nit see is very small differences: say 1.2 g for one brush and 1.4 g for another brush.
Good luck with the testing; looking forward to the final results.

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 08-03-2012, 02:47 AM
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Is that Cella soap?

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 08-03-2012, 06:49 PM
#8
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(08-03-2012, 02:47 AM)ChiTownCliff Wrote: Is that Cella soap?

Hi, the soap is Tcheon Fung Sing Barbe Rosse.

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 08-07-2012, 04:50 PM
#9
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Ok, so took some more measurements today and changed things around a bit. I lathered up using my usual process of lathering which is taking my brush out of warm water, giving it a good shake, then do 15 seconds of clockwise swirls, 15 seconds of counterclockwise swirls then another 15 seconds of clockwise swirls. I used the same steps to weigh the soap in my original experiment.

Today I used an Omega 31025 boar brush and got these results


Before After
Lather Lather
TFS Barbe Rosse .063kg .063kg
Proraso White tub .138kg .138kg
Pre de Provance .097kg .097kg

HuhHuh
What the heck?!? How could this be?? I lathered up the soaps and clearly used some up as I built a lather. Does the original format of not shaking the brush prior to building a lather really make that much of a difference? And it uses that much more soap? Well it is possible that not shaking out the brush and swirling till the lather thickens up uses up much more soap, but several more samples need to be taken to figure that one out. Also, the constant weights of the soaps before and after the lathering process could also be due to water seeping under the soap into the tub. (or being absorbed by the soap?) So it would be best if a weight measurement of the soap be taken after its had time to dry.

All is not lost though as I have come across something else that I'm excited about. On a whim, after lathering the Proraso white and subsequently with the PdP, I decided to weigh the brush loaded with lather, then weigh it after I've squeezed out all the lather.

Here are the results:
Lather Lather
loaded squeezed out
Proraso White .088kg .085kg
PdP .087kg .085kg

As you can see, a crude measurement of the weight of the lather. Its preliminary but I can say I had .003kg of usable lather of Proraso and .002kg of usable lather of PdP. This might not sound interesting, although this is possibly the beginnings of coming up with a density measurement for a lather. In otherwords, with a better measuring process, I can come up with a measurement, or number, for a soap that will represent the thickness of a lather that the soap will produce.

Maybe I'm getting a little overexcited with my own work and might not understand how much work this could possibly be, or its really something rudimentary that I'm making too big a deal about, but I think, in the name of science Biggrin, were on to something.

PS I did make an effort to find code to make tables for the weights but didn't work and got tired of messing with it.Biggrin

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 08-08-2012, 02:31 PM
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Weighed the soaps this morning and all three lost .002kg due to water evaporation.

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 08-08-2012, 09:10 PM
#11
  • Teiste
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Very interesting thread!
I remember Oversaturn doing kind of the same experiment but with Martin de Candre.Ill stay tuned to read further results.

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 08-11-2012, 06:45 AM
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I think it would make more sense to measure using smaller units of measurement...grams rather kilograms. Also, I think it is going to be very difficult to eliminate other factors.

I have seen people measuring the before/after effect and saying "well, it looks like I only use 0.01 grams of soap per use. I can get 1,000 uses from this puck, etc." Of course that isn't true and if someone is using such micro amounts of product, then their lather is just air and a little water...less than ideal.

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 08-11-2012, 09:11 AM
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Could always just count the number of shaves off of a puck and divide the weight by that much.

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 08-11-2012, 12:50 PM
#14
  • Persius
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  • Reading, England
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(08-11-2012, 09:11 AM)asharperrazor Wrote: Could always just count the number of shaves off of a puck and divide the weight by that much.
If you think about it, this is the least problematic way to approach this problem.

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 08-11-2012, 01:58 PM
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(08-11-2012, 12:50 PM)Persius Wrote:
(08-11-2012, 09:11 AM)asharperrazor Wrote: Could always just count the number of shaves off of a puck and divide the weight by that much.
If you think about it, this is the least problematic way to approach this problem.

Exactly. The only problem would be the little bit left over, but you can dig it out and subtract it from the total. Or not because you can't exactly get more shaves out of it.

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