didn't know!
Back to the sales pitch that I got from the salesman who maintained there
was absolutely no health risk involved (and yes, I will still wear a mask).
But if it is 60% silica then it does pose a health risk. To which he said
yes but it is ground so fine that it is technically soft and on the hardness
scale it reads "Hardness (mho) 1.0" where diamonds are 10.
I'm still a little undersided about that. I would have thought that silica
causes irritation to the lungs irrespective of granular size?
On Wed, Feb 23, 2011 at 4:23 AM, Carlos Contreras <maximo64@yahoo.com.mx>wrote:
>
>
> You are right Bill,
>
> the stearic acid is a "non wetable" material produced mainly from animal
> fat,
>
> the not wetable pproperty or in other words the property of water repelent
> is the key in the recipe.
>
> All the best.
>
> --- El mar 22-feb-11, oldstudentmsgt <wmrmeyers@sbcglobal.net> escribió:
>
> De: oldstudentmsgt <wmrmeyers@sbcglobal.net>
> Asunto: [gingery_machines] Re: Calling Chemistry intelligentsia : Parting
> powder specs
>
> A: gingery_machines@yahoogroups.com
> Fecha: martes, 22 de febrero de 2011, 21:50
>
>
>
>
> Things I've seen as parting dust in older foundry books:
>
> plumbago (graphite powder)
> wood flour (find sawdust)
> fine sand (silica dust)
> sea coal (not sure what it is, but except fine coal dust...)
>
> and have used dollar store talc-based baby poweder, which works well for
> aluminum, at least.
>
> the recipe Carlos provided sounds good. Now I have either remember or find
> out what stearic acid is... Seems like something I should know... soap? No,
> according to Wikipedia, it's a byproduct of hydrogenating animal fat, or
> certain vegetable oils. Based on tallow.
>
> http://en.wikipedia.org/wiki/Stearic_acid
>
> HTH!
>
> Bill in OKC
>
> --- In gingery_machines@yahoogroups.com, "Brite" <coldtoo2000@...> wrote:
> >
> > No help w/ your chemistry, but you can use also baking soda for parting,
> among other things.
> >
> > CT2
> >
> >
> >
> > --- In gingery_machines@yahoogroups.com, "Richard" <richardrigel101@>
> wrote:
> > >
> > > Greetings all, after an extreme search for PP I seem to have finally
> spoored up a non carcinogenic one. For various reasons I'm above average
> paranoid when it comes to my lungs and the search for even ordinary silica
> based PP has been exhaustive.(Anybody actually know what High Temperature
> plastic flour is?)
> > > The salesman assured me many times that this particular product has no
> health issues related to it, Would someone with a smattering a chemical
> learning please look over these specs and let me know if this is so.
> > > With thanks
> > >
> > > TALC POWDER Grade : T 10
> > >
> > > MINEROLOGICAL COMPOSITION
> > >
> > > Talc 98% Calcite <2%
> > > Free from Asbestos, Quartz & Tremolite by XRD Analysis
> > >
> > > PHYSICAL DATA
> > > Whiteness compared to MgCO3 92%
> > > Oil Absorption G.Oil/100g 42 pH 8.7
> > > Matter soluble in water 0.07%
> > > Specific Gravity 2.8
> > > Hardness (mho) 1.0
> > > Moisture at 105 degree C 0.01%
> > >
> > > CHEMICAL ANALYSIS
> > >
> > > SiO2 59.9%
> > > Al2O3 2.1%
> > > Fe2O3 1.2%
> > > CaO 0.9%
> > > MgO 30.6%
> > > LOI 4.8%
> > >
> > > PARTICLE SIZE
> > >
> > > Top Cut 15 Micron Average Particle Size 3 Micron
> > >
> > > Distribution
> > >
> > > < 15Micron 97.%
> > > < 10Micron 87.%
> > > < 3 Micron 51%
> > > < 2 Micron 36.%
> > >
> >
>
> [Non-text portions of this message have been removed]
>
>
>
[Non-text portions of this message have been removed]
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