Lather -- really close up

[Jethro1984]

Here's an experiment for you. Make some lather, let it sit, and monitor it while it collapses. I'm guessing you'll see bubbles form on the inside over time.

I did that with canned Gillette Foam. There's a YouTube video on it. Not the best of videos but you could see the structure break down and it became really airy (more of course than when new).

[YOUTUBE]http://www.youtube.com/watch?v=_Mh4SAJnZUo[/YOUTUBE]

[SiBurning]

I did that with canned Gillette Foam. There's a YouTube video on it. Not the best of videos but you could see the structure break down and it became really airy (more of course than when new).

Nice addition to the thread. Good basis for comparison.

I wouldn't be too surprised if some canned foams last longer than our home made ones. There's little or no water in them, and water drainage is one of the main mechanisms of collapse. (If I took a video instead of a still picture, you'd see the water flowing through my bubbles.) They use lubricants instead, and some of those lubricants are actually solids suspended or whatever in the foam. Also, the canned product probably has stabilizers to make and keep the foam.

I was actually making a slightly different point--a sort of challenge to Jim. That all lather is a foam, even if it doesn't look like one. Even Jim's awesome lather. We all know that canned lather is airy foam. And maybe my lather is awful, so other people need to do the experiment. Still, any shaving experiment is a good thing.

[Jethro1984]

I wouldn't be too surprised if some canned foams last longer than our home made ones. There's little or no water in them, and water drainage is one of the main mechanisms of collapse.

You're absolutely right with this. That stuff was dry coming out of the can. I considered doing the video again having added some water and stirred it to see what would happen but never did. The only reason I added this was when Jim mentioned there not being any "air" in the emulsification as he understood it. These cheap canned gunks obviously are more than 50% air or evaporating chemicals because they are squishy when they first come out of the can, but after several minutes, they are like bubbles stuck together with a bunch of holes everywhere (like swiss cheese). The video doesn't show it as I recall, but if you blow gently into the bowl, the "lather" all blows away like nearly dried soap bubbles.

P.S. I forgot how goofy my voice sounded in that video. I think it was the acoustics of my bathroom (it was open on 2 sides, my old apartment, huge counter) and the microphone on my digital camera (which I shot the video with). I don't normally sound like that, I don't think....

[SiBurning]

I wonder how a canned "gel" differs from a canned foam.

[Jethro1984]

I wonder how a canned "gel" differs from a canned foam.

I was wondering about that as well. I don't have any gel left though...else I'd bore the YouTubers again.

[Perkus]

I like the thread and the microscope images. The youtube movie not so much.

What does it actually prove? It should have entailed a comparative whipping up a soap or cream lather of the good quality stuff referred to and comments on its relative smoothness, wetness and so forth. Now it's just boring to watch.

Sorry, but no punchline there.

:o/
Perkus

[SiBurning]

I like the thread and the microscope images. The youtube movie not so much.

What does it actually prove? It should have entailed a comparative whipping up a soap or cream lather of the good quality stuff referred to and comments on its relative smoothness, wetness and so forth. Now it's just boring to watch.

Sorry, but no punchline there.

:o/
Perkus

Think of it as a control in the experiment. You can check your lather against it, and we can all compare the times for our own lather, and maybe for different soaps & techniques. Also, he saves us all the time time and trouble of buying a can of that junk just to check.

So who's gonna buy the can of edge gel?

[mikey]

Just pick up a jar of mayonnaise and let us all know how it works out.

Thanks,
Mike

...I'd really love to try to shave with an emulsion, but I wonder if it would be very runny, nothing at all like egg whites, and would probably be hard to form peaks. I don't think I could make a non-foam emulsion with a brush. Maybe a spoon...

[BlackBard]

In fairness, it's not *all* that painful to drag a blade across the skin with only water to lubricate. I don't think you need huge amounts of buffer, only a little.

Raw speculation, obviously.

Emphasis on "Raw."

[SiBurning]

Just pick up a jar of mayonnaise and let us all know how it works out.

Thanks,
Mike

You just want to see me with egg on my face.

Anyway, mayo is also whipped. Milk & butter are better examples of an emulsion with no air.

So, I shaved with that 5% Tabac stuff. It's slimy, offers little protection, and isn't very lubricating. It also evaporates pretty fast. No doubt the water-soap ratio is off. It wasn't completely bad, just not good. You can try this at home by heating up some water to 120-160F depending on the soap and dissolving some scraped soap into the water. But don't use your brush at all, just apply it as is, or you'll stir up a foam.

Here's some melting points as a guide
lauric acid 44C (111F) from coconut & palm kernel oil
myristic acid 54.4C (130F) from coconut & palm kernel oil
palmitic acid 62.8 (145F) from palm oil & tallow
stearic acid 69.6 C (157F) from palm oil & tallow

[Sullybob]

Here's an experiment for you. Make some lather, let it sit, and monitor it while it collapses. I'm guessing you'll see bubbles form on the inside over time.

I have noticed that towards the end of my shave as the lather in the bowl starts to break down larger and larger bubbles start to form.

[SiBurning]

Scaling Behavior in Shaving Cream (pdf from 1991) measures & explains how foam degenerates. There's some good pictures and chart. It uses Gillette Foamy, but they claim all foams act the same.

It looks like there's two separate phases to how foam degrades. It hardly degrades for the first 10 minutes. After that, it degrades steadily. They're not exactly straight lines--there might be a curve to them, but there's definitely two separate phases.

Here are the mechanisms for degradation:
Most important is diffusion of gas to other bubbles.
They claim they never saw film rupture, where a bubble just bursts, and two join into one.
They claim that (gravitational) drainage is insignificant. I've read otherwise, but those were for flowing foams, such as fire fighting foam being pumped through an enclosed space.

There's one other thing going on. There's always some flow between the bubbles, and some very tiny bubbles are part of that flow. At various points in time, a sudden rearrangement takes place, and several nearby bubbles shift and move. This document says these become more frequent over time. I can't make out whether they correlate this with how the bubble grow larger, but the math shows a similar looking equation that says both behaviors increase over time in a similar way, if not exactly at the same speed or acceleration.

I wonder how much additives like surfactants can make that first phase last longer. They might even slow down the rest of the curve.



Here's the practical point
Anyway, this points to a good criteria for checking your lather. It should break down very slowly for a good while, and then at some point, the breakdown might accelerate. If it starts to break down too soon you might want to work on making a better lather. How long is really a guess, but the canned stuff hardly changes in the first 10 minutes. In fact, you might not notice all that much change even after an hour.

[Fletch]

In fairness, it's not *all* that painful to drag a blade across the skin with only water to lubricate. I don't think you need huge amounts of buffer, only a little.

Raw speculation, obviously.

I have touched up parts of my face with just water and a razor. I wouldn't do it as the only thing on my face after 2 or 3 days growth but I have hit stubble patches with a wet face. I've even popped off a few stray whiskers here and there I've missed around the corner of my mouth dry, just grab the razor and swipe a pass or two on the offending spot. Again I wouldn't recommend doing large patches like that. I have had times where canned stuff has sit out for hours. It basically becomes a shell of it's former self. it will most likely retain it's shape just look like it has big holes throughout it.

[kingfisher]

......
I was actually making a slightly different point--a sort of challenge to Jim. That all lather is a foam, even if it doesn't look like one. Even Jim's awesome lather. .....

Agree with this. Lather IS foam. Albeit good lather is foam with very small bubbles.

[honed]

Great pictures & great discussions, thanks guys

It would be really great to see the differences between various soaps & creams. Like Tabac & Willams & an Artisan glycerin soap.

[Jethro1984]

I like the thread and the microscope images. The youtube movie not so much.

What does it actually prove? It should have entailed a comparative whipping up a soap or cream lather of the good quality stuff referred to and comments on its relative smoothness, wetness and so forth. Now it's just boring to watch.

Sorry, but no punchline there.

:o/
Perkus

And then somebody would have complained that I never did a video on canned goop.

The point was that it was supposed to show how airy the stuff is to begin with and then how it just degrades from there. It also shows the idea behind the SLS (sodium lauryl sulfate) in that I agitated it 0, and it bloomed into a gob of foam. I didn't think beforehand that it would be particularly interesting, I was just bored, had a bunch of goop left, and thought i'd make a video.

You don't have to like it...but you admit that you watched it, and you probably watched the whole thing.

[SiBurning]

I put yogurt under the microscope for a comparison, but won't show the pictures because there's not much to see and what's there looks a bit biological. There's no bubbles to speak of. The structure seems to be more like random chunks of snow in liquid. There's also nasty bacteria. This was Dannon vanilla.

[Fletch]

The bacteria is likely the "live and active cultures" that is talked about on the labels of most yogurt. That's supposed to be a good bacteria.

[sychodelix]

Lather science. Very nice work.

[mars]

In the original pictures, are the bubbles filled with air or water?