Flint in hot process

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Holuden

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Hi!

A certain someone kindly asked me to make a batch with flint. She is very fond of cosmetics and other products made with it. Browsing various websites gave me no insights on howtos with silica in soapmaking whatsoever. Apparently NaOH reacts with SiO4 and creates new type of salt, so I decided simply grind it into a fine dust and mix it with soap dough after gel phase with low ph.

What do you think, is it a viable decision or there may be problems?

Thanks in advance!
 

ResolvableOwl

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After gel phase, soap is hard and you cannot mix in anything any more. Also, the pH of soap will never be “low” as in “no longer alkaline”.

Flint as an ingredient in soap appears highly questionable to me. I'm not exactly fond of the idea to have something with the tactile properties of glass shards in a product to rub on skin.

Flint (quartz) does in principle react with/dissolve in NaOH, though I don't think you are able to grind it up that finely to get a decent reaction rate. On top of that, should it really dissolve, there is no reason why to use flint as a silica source, and you could just use any other water glass.
 

maryloucb

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I'm also curious why you would want flint, or any other sort of sandy mineral in soap. You would have to totally pulverize it in order for it not to be incredibly scratchy. How are you grinding it?
 

Holuden

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Oh well, the client is into esotericism and flint has some deep meaning for her. She procures flint infused toothpaste and skincare and is very fond of it. So here is the reason for experiment.

Another one asked me to infuse soap with amber dust for similar reasons. I grinded it with mortar and pestle to sandy state and then powdered with coffee mill. Cooked soap in oven then mixed it with 5% amber and scents before molding. Result felt as if washing with sand. Weird but not scratchy. The client was satisfied. So I consider using the same method with flint to see what happens.
 

ResolvableOwl

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Amber is something totally different, since it is soft (Mohs hardness 2…2.5, while flint is at 7). Resin/rosin has its place in soapmaking for a long time for good and totally secular reasons (it dissolves in lye and adds cleansing power to a soap, just like oils do when they saponify).

If you think it's worth ruining your mortar/pestle and coffee mill, feel free to try out if you can get the flint fine enough to be no more scratchy.
 

Marsi

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flint is hard and brittle
flint dust is easiest to create with a hammer
fun too - dont breathe the dust
 

Obsidian

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I'd make her sign a waiver stating she is aware that flint in soap could potentially cause cuts and you won't be held accountable.
Even pulverized, I imagine the individual grains will have sharp edges.
 

Zany_in_CO

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She is very fond of cosmetics and other products made with it.
Here is some info about SILICA in powder form used in cosmetics.
She procures flint infused toothpaste and skincare and is very fond of it.
As it happens I have a sample of "SILICA GEL" on my soaping shelf which is the type of silica used in toothpaste. I have not tried using it but the directions say,"Add 1/4 teaspoon to 16 oz. room temp liquid soap to thicken."

ETA: I tried it. it is an incredibly fine powder -- think *eye shadow* -- with a pleasant feel to the skin. My thinking is, if it can be used in liquid soap, why not try it in hard bars? The information in the link above says, "imported from Germany" so that may give you a clue to where you might be able to purchase it.

Just a thought. 😁
 
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paradisi

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The part of silica dust that's harmful to the lungs is too small to be seen, or for a common mask to protect you.

And those tiny particles hang in the air for several hours to days. People wreck their lungs breathing those dusts.

You absolutely should not grind flint, nor be adding it to soap as though it was walnut shells.
 

Marsi

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agree - common masks are not rated for dust particulate protection

wet the work
drop the dust

for the third and final time, dont breathe the dust
 

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