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Mythrill
09-30-2013, 04:47 PM
Hi, guys. Recently, I've been wanting a really delicate, transparent white for my acrylics something that would have similar tinting properties than those of lead, but non-toxic.

You have probably heard of Eggshell White before. It's basically the egg shells of chickens boiled in vinegar in 24 hours. The book The Pigment Compendium has an ancient quotation (translated to English) from the Italian book Secreti di Don Alessio Piemontese, published in 1557:


Then put these crushed eggshells and water into a clean bowl, and let the powder settle to the bottom and then drain away the water carefully and allow the powder to dry naturally and you will have an incomparable white which cannot be surpassed by lead white [biacca] or any other white in
the world if it is made carefully and well.

So, is this Eggshell White that good?

My family bought some chicken eggs, but since I don't want to waste them (just by getting the shells and discarding their yolks,) I researched a little more. It turns out this Eggshell White is another form of Calcium Carbonate the same material of gesso!

Knowing this, I bought some marble dust and followed the recipe (mixed it with equal parts of vinegar.) It seems it is a very warm white (compared to Titanium White (PW6,) and maybe similar to Lead White (PW1) in hue. One notable difference is that when Calcium Carbonate is being converted into Calcium Acetate, it stops forming a hard paste, like Calcium Carbonate does.

What do you guys think? Would Calcium Acetate be a good replacement for Lead White (PW1)? It seems to attract water in powdery form, so is it stable enough to be used in oils (more specifically, does it oxidize in oils?)

Mythrill
09-30-2013, 11:43 PM
Hi, guys. I'm sorry. I would like to add a few corrections: it seems that marble dust (gypsum) is actually calcium sulphate, and that is converted into calcium carbonate. I got the wrong information from Wikipedia on "Calcium Acetate: (found in http://en.wikipedia.org/wiki/Calcium_acetate)"


Calcium acetate can be prepared by soaking calcium carbonate (found in eggshells, or in common carbonate rocks such as limestone or marble) in vinegar: [...]


What's important anyway is the calcium carbonate: it works pretty well as matte medium in acrylics, as a translucent white in oils, and a very transparent white that kills the gloss of Titanium White (PW6) and gets rid of its chalkiness (for a transparent white in both mediums, mix a small amount pure titanium white with chalk, and not vice-versa!)

By the way, can any mod fix the topic to say "Calcium Carbonate" instead of "Calcium Acetate?"

Gigalot
10-01-2013, 06:21 AM
Calcium Carbonate has a low refractive index. It is good white in fresco or mural painting. It oil it is not a whites, it is just filler. There are other cheap white which have better refractive index:- Barium Sulphate and Magnesium Silicate.
Bone White - completely burned cow bones, white powder, which is Calcium Phosphate and Calcium Carbonate mixture - porcelain industrial white pigment, stronger and better than Marble dust.

Very common Lead White replacement is a mixture of Zinc Oxide and Titanium Dioxide, which many people hate because it contains "brittle zinc". :D

Cheaper variant is Barium sulphate and Titanium white mixture - great for artist's, worrying about Zinc content. :lol:

Zirconium white oxide, an AeroSpace white pigment might be the best replacement to Lead, but I never heard about it's usage in Artist's oil paint with the name Zirconium White!

(manufacturers prefers to use artificated pigments in Acrylic paint, even if natural pigments are not expensive. Some natural impurities, safe in oil paint, can affect PH in acrylic emulsion and coagulate it directly in tube. PH in Acrylic paint must be strongly basic and balanced around PH=9. The artificated pigments formulation, prepared for acrylic, are free of acidic or soluble salt content)

Mythrill
10-01-2013, 06:56 PM
Calcium Carbonate has a low refractive index. It is good white in fresco or mural painting. It oil it is not a whites, it is just filler. There are other cheap white which have better refractive index:- Barium Sulphate and Magnesium Silicate.
Bone White - completely burned cow bones, white powder, which is Calcium Phosphate and Calcium Carbonate mixture - porcelain industrial white pigment, stronger and better than Marble dust.

Giga, marble dust (gypsum) is calcium sulphate. I'm converting marble dust into calcium carbonate.

I'm testing it in my own paint: my own calcium carbonate, both as an extender and a delicate white pigment (with a touch of titanium dioxide.) You can see it in the dead layer (stormy sky.)

http://www.wetcanvas.com/Community/images/01-Oct-2013/96427-Lost_Paradise_-_Dead_Layer_Stage_1.jpg



Please note that, considering my machine tries to "round" colors (white balance,) the sky is not the correct color cast. It should be bluer, not have a green tint.

Also, the dead layer is not complete yet.

Gigalot
10-02-2013, 10:27 AM
Does it means Calcium Carbonate and Titanium Dioxide mixture is a good replacement for Lead white? And even Zinc white?
In this mixture Titanium white is a pigment, while Calcium Carbonate is an Extender. Extenders are widely in use to dilute Phthaloes, Organic pigments, Cadmiums, Student grade paints, Domestic paints e.t.c
Most of paint manufacturers like to use Zinc white + Titanium white to mix their "Lead white " imitation.
I had never try real Lead White pigment and can't say which is better thing. But real Lead has a very fast drying properties, while titanium is inert pigment and dries very slowly itself. In Water media Lead white is not useful thing - it darkens greatly in fresco or egg tempera due to atmospheric hydrogen sulphide content. Oil vehicle prevents darkening.

Mythrill
10-02-2013, 01:09 PM
Does it means Calcium Carbonate and Titanium Dioxide mixture is a good replacement for Lead white? And even Zinc white?
In this mixture Titanium white is a pigment, while Calcium Carbonate is an Extender. Extenders are widely in use to dilute Phthaloes, Organic pigments, Cadmiums, Student grade paints, Domestic paints e.t.c
Most of paint manufacturers like to use Zinc white + Titanium white to mix their "Lead white " imitation.
I had never try real Lead White pigment and can't say which is better thing. But real Lead has a very fast drying properties, while titanium is inert pigment and dries very slowly itself. In Water media Lead white is not useful thing - it darkens greatly in fresco or egg tempera due to atmospheric hydrogen sulphide content. Oil vehicle prevents darkening.

Hi Giga,

I didn't know about this lead white problem in water-based media. Thanks!

Also, regarding the paints, I've made two: one solely with calcium carbonate, and another with calcium carbonate + Titanium White. The reason is because I've noticed that, as an extender, calcium carbonate will lighten colors while still giving them body, which doesn't harm the paint film. Much ironically, "chalk" doesn't make paints... chalky! And as a bonus, it keeps paints matte.

The problem with calcium carbonate, however, is that it you need an acid to make it. This makes acrylic paint film slowly unstable, and considering I haven't developed a method to remove the impurities of acetic acid (used in traditional recipes to make "Eggshell White",) I've changed the formulation to gypsum (calcium sulphate.) It has similar properties, but it will harden on water. This is annoying, as you need to keep breaking it while you make the paint film.

Gigalot
10-02-2013, 04:00 PM
Calcium carbonate reduce domestic paint longevity. Pure Iron oxide red can stay 10 years in outdoor alkyd enamel, while cheaper formulation with Calcium carbonate extender can stay two or three years, not more, without chalking and destruction. Calcium Carbonate is weak, silica or glass powder seems to be stronger, better fillers. But "do not breath silica dust" danger and cheapo chalk is a cause of low quality domestic enamels production here. But the standard, quality enamel formulation is absolutely calcium carbonate free. I have seen the table with enamel longevity test, depended of chalk content. Chalk can be used only for indoor, weak paints.
I guess, it is better do not add too much calcium carbonate to artist's paint.
Gypsum is worst thing in paint. Strong, hard mineral powder needs to make a good quality filler. Aluminum oxide, Magnesium silicate or even Calcium phosphate, Mica, powdered glass.

karenlee
10-02-2013, 04:17 PM
Interesting! I wonder why we take calcium carbonate to strengthen our bones, if the stuff is so weak!?!

Gigalot
10-02-2013, 05:06 PM
Interesting! I wonder why we take calcium carbonate to strengthen our bones, if the stuff is so weak!?!

Bones is mostly Calcium Phosphate (Apatite) and organic composite material - very strong!
http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
Apatite is much harder than Calcite

Mythrill
10-02-2013, 08:34 PM
Calcium carbonate reduce domestic paint longevity. Pure Iron oxide red can stay 10 years in outdoor alkyd enamel, while cheaper formulation with Calcium carbonate extender can stay two or three years, not more, without chalking and destruction. Calcium Carbonate is weak, silica or glass powder seems to be stronger, better fillers. But "do not breath silica dust" danger and cheapo chalk is a cause of low quality domestic enamels production here. But the standard, quality enamel formulation is absolutely calcium carbonate free. I have seen the table with enamel longevity test, depended of chalk content. Chalk can be used only for indoor, weak paints.
I guess, it is better do not add too much calcium carbonate to artist's paint.
Gypsum is worst thing in paint. Strong, hard mineral powder needs to make a good quality filler. Aluminum oxide, Magnesium silicate or even Calcium phosphate, Mica, powdered glass.
Hi Giga!

I see what you mean by outdoor painting, but most artistic paint won't be exposed to rain and humidity, right?

Are you sure about the gypsum / chalk reducing artistic paint longevity? Gouache ("opaque watercolor") was traditionally gum arabic, honey and calcium carbonate to make paint opaque, wasn't it?

Also, some paints are stable in one media, but not in another. Prussian Blue (PB27) is a prime example of paint that's stable in oils, but not acrylics (acrylics need to be highly alkaline ideally a PH of 8, and not less than 7.5.)

Another example would be Yellow Ochre (PY43.) It's extremely stable on almost every media, except fresco (if it has traces of gypsum) and egg tempera (it tends to discolor and become greenish.)

Gigalot
10-03-2013, 11:44 AM
I have Mica paint as an extender for whites and transparent colors.
http://www.dickblick.com/items/02115-1454/#colorpigments
It has good, time tested permanency. Beautiful gloss. As mica flakes are durable and flexible, it can be a very good additive to oil paints.
I had never give Calcium carbonate to try, but, as I heard, Egg shell is a best grade of Calcium carbonate ever. Do not tested for me, but you can give it to try! :)
But why do you need to use an extender, Mythrill? To make a paint with a better thickness? :clear:

Mythrill
10-03-2013, 01:03 PM
I have Mica paint as an extender for whites and transparent colors.
http://www.dickblick.com/items/02115-1454/#colorpigments
It has good, time tested permanency. Beautiful gloss. As mica flakes are durable and flexible, it can be a very good additive to oil paints.
I had never give Calcium carbonate to try, but, as I heard, Egg shell is a best grade of Calcium carbonate ever. Do not tested for me, but you can give it to try! :)
But why do you need to use an extender, Mythrill? To make a paint with a better thickness? :clear:
Giga, Egg shells can give you 95% pure Calcium Carbonate, while gypsum will give you Calcium Carbonate of up to 98% purity (though gypsum is trickier to refine.) Of course, impurities in each material are different, and can give you different working properties.

Regarding the extenders, I've discovered that calcium sulphate / carbonate (with no Titanium White) allow me to lighten acrylics to the most soft tints without making them "chalky" (looking too whitish.)

Of course, I could simply use water, but water might damage the paint film if used too much. Another option would be matte medium (I prefer a matte over gloss finish,) but it doesn't give me "tooth" for the upper layers as a combination of Calcium Sulphate / Carbonate and gloss medium do.

This extender combination is being really useful right now. From my observations creating earth paint, I believe nearly almost all paints in the past were much more transparent than they are today. With them, I can make my premixed black so soft it will only tint the underlayers and only cover them if / when I *really* want to. I believe (though I might not be correct, of course) this was essential to the glazing techniques of the past.

I'm also considering to simulate an "enamel-like" finish to the upper layers, but gloss medium is not quite the same.

Regarding mica, it seems to be a nice extender, though it will give a iridescent effect that I'm not always after. In oils, I use a combination of linseed and silica, though I tested calcium carbonate and tints were so much more delicate as well! (Even more so than in acrylics.)

Gigalot
10-03-2013, 02:22 PM
Pure mica is not "iridescent" Iridescent properties has specially prepared, coated mica. Nano-thin dichroic filters on mica particles, use the principle of interference.
Mica without optical coating is just glossy, pearlescent white pigment.

You are right about more transparent paints in the past, medieval pigments have better quality. :)
I guess, acrylic paints are mostly more transparent than oil paint is. Anyway, there are special transparent mediums, which are tested by their manufacturers.

Mythrill
10-03-2013, 07:23 PM
Pure mica is not "iridescent" Iridescent properties has specially prepared, coated mica. Nano-thin dichroic filters on mica particles, use the principle of interference.
Mica without optical coating is just glossy, pearlescent white pigment.

You are right about more transparent paints in the past, medieval pigments have better quality. :)
I guess, acrylic paints are mostly more transparent than oil paint is. Anyway, there are special transparent mediums, which are tested by their manufacturers.
Giga, regarding transparency: it depends. Some yellows (PY65 and PY83, for example) are far more transparent in oils than they are in acrylics. Cerulean Blue (PB35,) on the other hand, is described as opaque in oils, but the version I have in acrylics is extremely transparent. I don't know if it's because of low pigment load or if it's something particular to it.

About the special mediums: yes, I could buy them, but there's something extremely fun about making our own materials. You learn more about how they work and how you can make them more stable.

There's also the ingredients: for instance, most matte mediums manufacturers won't disclose their ingredients. By making my own medium, I know exactly what's in it, for instance: that isn't mixed with another paint to make it more attractive, and I also think they're far stronger. For instance: I made not more than 30ml of opacifier, but it's far stronger than 250ml of Pebeo's Matte medium. With no more than the equivalent of a few drops, I can lighten Phthalo Green and make it behave more like Viridian (PG18,) if I so wish. With Pebeo's matte medium, I'd need at least a full spatula or more for the same quantity of paint.

There's another interesting thing I've learned: I have a few tubes of Winsor & Newton Acrylics turning into "cottage cheese" consistency. Thanks to the Do It Yourself section of Golden, I learned that this consistency happens when the PH of the paint is too acidic and that I must add an alkaline substance to restore film integrity just water won't do.

Regarding preservatives, you've suggested me some like boric acid and sodium fluoride. Unfortunately, boric acid lowers the PH of the paint too much, and sodium fluoride is the only "safe" preservative that works, because of its alkalinity (the other would be ammonia, but the smell is too strong.) Unfortunately, I bought it from the supermarket and it has an artificial sweetener, so paint smells a bit annoying but I guess I can live with it. As soon as I can, I'll ask a drug store to make fluoride without any scent.

Gigalot
10-04-2013, 04:29 AM
Regarding preservatives, you've suggested me some like boric acid and sodium fluoride. Unfortunately, boric acid lowers the PH of the paint too much, and sodium fluoride is the only "safe" preservative that works, because of its alkalinity (the other would be ammonia, but the smell is too strong.)

Sodium salt of boric acid - sodium tetraborate (borax) has basic PH. Good to have PH indicator paper. Acrylic is very sensitive to PH.

I guess, you are first , who try experiments with acrylic. :)

Mythrill
10-04-2013, 05:45 AM
Sodium salt of boric acid - sodium tetraborate (borax) has basic PH. Good to have PH indicator paper. Acrylic is very sensitive to PH.

I guess, you are first , who try experiments with acrylic. :)
Thanks for the paper indicator idea, Giga!

Regarding sensitivity: indeed, acrylics are very sensitive to PH. They need to have a PH higher than water ideally from 8.8 to 8, and not less than 7.5 (water usually has a PH of 7, but it may be slightly acidic, for instance, 6.8, due to pollution.) Of course, you can still add water normally to lighten paint as long as you use it right away; this way, the paint film won't have time to become unstable.

I mentioned Golden's section about making your own paint, but forgot to mention their site. Here it is: http://www.goldenpaints.com/justpaint/jp7article1.php

I used to "worship" Winsor & Newton, but they're losing space to Golden in my heart due to how more well-documented (and more stable) Golden's acrylics are! Daniel Smith's Acrylics would be tied to Golden or be a close second not because of their documentation, but because of their sheer stability and unique colors.

catalino
10-09-2013, 06:36 PM
Cremnitz white (lead white, basic lead carbonate) can not be replaced from others pigment or cheap fillers as calcium carbonate.

Mythrill
10-09-2013, 07:20 PM
Cremnitz white (lead white, basic lead carbonate) can not be replaced from others pigment or cheap fillers as calcium carbonate.

Are you saying that just because the replacement seems so simple or genuinely because of some unique characteristics of PW1? Wouldn't you care to explain *why* this isn't possible in more detail?

Mythrill
10-09-2013, 10:52 PM
Oh, Catalino, here's a fragment of an article quoted by no one else other than Natural Pigmentsabout how to make a "mock" lead white. It's called Brighter than White, from Thomas Jefferson Kitts (article freely highlighted on key points:)



First, mix a tiny amount of ochre paint into a generous amount of titanium white. This will shift the cool bias titanium pigment has towards the warmer cast of lead. [...]

Next, you need to reduce the tinting strength of the titanium in your titanium/ochre white. To accomplish this, you start by mixing some linseed oil into a pile of finely-ground marble dust. (aka, calcium carbonate [sic]) [...]

And finally, to emulate the impasto effect lead white imparts to a brush stroke, try incorporating a small amount of artist-grade beeswax. [...]

You will likely want to experiment with different proportions of these additives to find your preferred mock lead, but once you find it take note for future reference. [...] Sealed properly, your mock lead white should last as long as any other oil paint.


Please note: contrary to what's being said in the article, marble dust (gypsum) is calcium sulphate. It is known as gypsum and it's alkaline, while calcium carbonate is a salt of calcium, an inert pigment (doesn't react neither with weak acids or bases.) When painting, their properties are almost identical, but calcium sulphate will harden if you mull it with water (you'll need to keep breaking in water-based media to make a good paint,) whereas calcium carbonate will not.
Article (as quoted by Natural Pigments:) http://paintingperceptions.com/sounding-technical/the-great-lead-white-shortage
Original source: http://www.thomaskitts.com/search?q=For+Those+Who+Refuse+to+Paint+with+Lead+but+Wish+They+Could

Gigalot
10-10-2013, 08:45 AM
Article (as quoted by Natural Pigments:) http://paintingperceptions.com/sounding-technical/the-great-lead-white-shortage[/LIST]
Original source: http://www.thomaskitts.com/search?q=For+Those+Who+Refuse+to+Paint+with+Lead+but+Wish+They+Could

I had never used Lead White, but I got one old tube with it. Do not add yellow ochre to paint which used to emulate real Lead White. Lead White is siccative, and still is welcome because of it's siccative properties. Therefore, add Black oil, boiled with a lead oxide, 3% lead soap solution in linseed oil. It is naturally brown and it gives a proper color to Titanium White. Add Mica pigment to increase gloss and reduce the tinting strength of the titanium. Add also Cobalt Siccative to make a highest possible drying properties to a Titanium White and voila! Leaded black oil with Cobalt drier will kick this Titanium White to dry even faster than "Magic Lead White". And Mica will completely beat this Lead White in sheen. Add Lead Stearate and give "natural lead softness" to titanium. :D

Mythrill
10-10-2013, 10:05 AM
Never used Lead White, but I got one old tube with it. Do not add yellow ochre to paint which will emulate Lead White. Lead White is siccative, and still is welcome because of it's siccative properties. Therefore, add Black oil, boiled with a lead oxide, 3% lead soap solution in linseed oil. It is naturally brown and it gives a proper color to Titanium White. Add Mica pigment to increase gloss. Add also Cobalt Siccative to make a highest possible drying properties to a Titanium White and voila! Leaded black oil with Cobalt drier will kick this Titanium White to dry even faster than "Magic Lead White". And Mica will completely beat this Lead White in sheen. Add Lead Stearate and give "natural lead softness" to titanium. :D
Hi, Giga!


I've researched a little about this Black Oil, and I thought the warm cast was really interesting. Is this what you're talking about? http://www.oldmastersmaroger.com/black-oil-painting-medium-4oz/

Unfortunately, I can't add this medium to acrylics. :(

Regarding adding Yellow Ochre: I wasn't suggesting adding Yellow Ochre, just quoting the article. My own calcium sulphate alone (bought it from an industrial supplier nearby) has a naturally warm tint to it. However, I see no harm in adding it if you want, as natural Yellow Ochre (PY43) might have traces of gypsum, and yet it's perfectly safe for your paint (except if you're painting in Fresco.) If I felt I had to tint it, personally I'd add just a little of Transparent Yellow Iron Oxide (PY42) to the mix.

In my own recipe, I tried to focus on the optical properties of Lead White without the toxicity and the reactivity linked to it.

Your suggestions of mica to add iridescence and gloss really started to grow on me. However, I can't find mica powder in small quantities for sale to the end user. I can find barite, but I don't know about its gloss properties Do you know of any other fillers that increase gloss could be safely used in acrylics and would be non-toxic?

If everything else fails, I'll just convert calcium sulphate into calcium carbonate (it gives you finer particles compared to calcium sulphate from eggshells,) stabilize it, and use it in acrylics.

Gigalot
10-10-2013, 02:05 PM
In my own recipe, I tried to focus on the optical properties of Lead White without the toxicity and the reactivity linked to it.


I can say that optical properties of Titanium White is much better than Lead White can have. Titanium is much whiter, it has much stronger covering power,
It do not darkens, do not react with oil, which cause Lead White discoloration, It is much less yellowing pigment with excellent chemical stability.
But people know how strong, big Heresy to most artist's books are these words:lol:

You do not need to reincarnate worst optical properties! More important things in Lead White's mythology properties is a "fantastic consistency", drying time, and "unbelievable" longevity of this pigment. It form Lead Soap in oil medium. This soap is a magic substance, which can increase oil paint longevity ten times from hundred years to a thousand years. This soap can cure oil film better than antibiotic can kill microbes. :) We do not need to replace Lead White, the main task is "how to replace Lead Soap" in oil film without affect on its longevity.

http://www.si.edu/mci/downloads/articles/tusoma_paper.pdf

catalino
10-10-2013, 04:35 PM
If you are satisfied of your choice, you can use titanium bioxide anatase, titanium bioxide rutile, zinc oxide, calcium carbonate, calcium sulfide, unbleached titanium bioxide, Marseille soap, wheat, cement, fish & chips and marshmallows instead Cremnitz white! For me, pure lead basic carbonate, specially stack process lead white, the purest form of Cremnitz white, cannot be replaced, but only simulated. Ciao. Max.

Gigalot
10-10-2013, 06:14 PM
If you are satisfied of your choice, you can use titanium bioxide anatase, titanium bioxide rutile, zinc oxide, calcium carbonate, calcium sulfide, unbleached titanium bioxide, Marseille soap, wheat, cement, fish & chips and marshmallows instead Cremnitz white! For me, pure lead basic carbonate, specially stack process lead white, the purest form of Cremnitz white, cannot be replaced, but only simulated. Ciao. Max.

No one paint can be replaced, only simulated. Alizarin, Vermilion, Viridian, Chromium Oxide and E.t.c.
But, just interesting, Max, which is an advanced properties you really love in Flake White? Longevity? Mixing properties? Or optical advantages?
Personally, I don`t know things which can not be painted using Titanium and Zinc white. But, you know, I am not Flake White expert. Production of Flake White was long ago discontinued here..I had never seen it even in my childhood. A tube which I got, is 57 years old. But still has a good paint into it. :)

catalino
10-10-2013, 07:29 PM
Probably I'm the greatest expert of Cremnitz white. Unfortunately, I understand perfectly the english language, but I don't know a perfect english grammar (I speak a very good German language, I have practically studied only German for 10 years). For this reason, I must organize a grammatically correct reply for speak on lead white. Max.

Mythrill
10-11-2013, 12:59 AM
Probably I'm the greatest expert of Cremnitz white. Unfortunately, I understand perfectly the english language, but I don't know a perfect english grammar (I speak a very good German language, I have practically studied only German for 10 years). For this reason, I must organize a grammatically correct reply for speak on lead white. Max.

How do you claim to be the "greatest expert of Cremnitz White?" Do you manufacture it? Have you written research about it?

You don't need a perfect grammar to explain why Lead White (PW1) is so special. Just a good enough grammar, clear, concise writing, and facts.

The fact that no one other than Natural Pigments itself suggests calcium carbonate and a little of Titanium White (PW6) as a substitute for the most important features of PW1 warmth and making colors lighter is very telling.

Furthermore, comparing calcium carbonate to painting with cement is an absurd analogy. Calcium carbonate is inert, and if you're questioning its stability, it's important to note that Velasquez and Rembrandt themselves used "putty medium" a mix of calcium sulphate and calcium carbonate widely for transparent effects. How's the state of their works again?

Here's a nice source about "putty medium:" http://www.tadspurgeon.com/puttymedium.php. Of course, this source about it is not the only one, and you can check the links I have posted before in this topic.

catalino
10-11-2013, 03:47 AM
The reply to your two initial question is yes. In order to cement, you don't have understand my humour (I speak in my post of marshmallows!). Use your putty, calcium carbonate, all that suggest your fantasy instead Cremnitz white. I suggest at this point all the white chemical compounds, without limitations, and buon divertimento. P.S.: tad Spurgeon is simply a genius!!!!

Gigalot
10-11-2013, 04:51 AM
The reply to your two initial question is yes. In order to cement, you don't have understand my humour (I speak in my post of marshmallows!). Use your putty, calcium carbonate, all that suggest your fantasy instead Cremnitz white. I suggest at this point all the white chemical compounds, without limitations, and buon divertimento. P.S.: tad Spurgeon is simply a genius!!!!

There are two questions, two major strategy to use paint: one is "Which is non-toxic?" and the second is "Which is better?"
Non-toxic way is to use water as solvent, titanium as white and hansa as yellow.
The second way is to use turpentine, cadmium, lead white, cobalt to make painting better.

Lead white has an unique properties, it can push to dry to a normal polymer film even oleic fatty acid, which other siccative can't do. Lead only.

After some time of world-wide lead panic, paint manufacturers start to use lead drier again to improve industrial paint properties. In Europe they begin to use normal oil paint again to cover wood materials instead of emulsion "environmental" paint.
Use Lead white if you are really sure it can make your painting better. :)

catalino
10-11-2013, 06:07 AM
You have PERFECTLY reason. You are an expert of chemistry better as me. I will use toothpaste for paint. Toothpaste has a smell flavour of mint or strawberry. I love strawberry-I eat sandwiches with strawberry gelatine and peanuts cream, like tenente Colombo. Ciao

Mythrill
10-11-2013, 06:30 AM
You have PERFECTLY reason. You are an expert of chemistry better as me. I will use toothpaste for paint. Toothpaste has a smell flavour of mint or strawberry. I love strawberry-I eat sandwiches with strawberry gelatine and peanuts cream, like tenente Colombo. Ciao
Titanium white is used to color your white toothpaste, "chemist."

catalino
10-11-2013, 07:13 AM
[edit] But I know that toothpaste contain titanium bioxide. Pharmaceutical products contain titanium bioxide as filler. This is an actually problem, titanium is a metal. I use the reason, but I reply to you for diverting me. Your discussion on Cremnitz white is simply absurd.

Mythrill
10-11-2013, 07:43 AM
[edit]But I know that toothpaste contain titanium bioxide. Pharmaceutical products contain titanium bioxide as filler. This is an actually problem, titanium is a metal. I use the reason, but I reply to you for diverting me. Your discussion on Cremnitz white is simply absurd.
That's dioxide, not bioxide. And no, that's not a problem: Titanium Dioxide (PW6) is a metal, but not a heavy metal. It won't bioaccumulate in your body like lead or mercury. Phthalocyanine Blue (PB15) is a derivative of copper, and it is so safe it is used even in children's paints. So what?

catalino
10-11-2013, 08:43 AM
My last note: in chemistry, di = bi =2, dioxide=bioxide. You have a problem named "marchese".

Mythrill
10-11-2013, 12:02 PM
There are two questions, two major strategy to use paint: one is "Which is non-toxic?" and the second is "Which is better?"
Non-toxic way is to use water as solvent, titanium as white and hansa as yellow.
The second way is to use turpentine, cadmium, lead white, cobalt to make painting better.


Hi Giga!

I agree with most of your message except for putting Titanium White (PW6) in the same caliber as Hansa Yellow(s) (notably PY3 and PY74.)

Titanium White is a really inert pigment, and it corresponds for 80% of the white used in the world, usage ranging from coating of airplanes to your toothpaste. It doesn't react to certain pigments or atmospheric problems like Lead White (PW1) does, and its biggest flaw of Titanium White is its strongest weakness: being too white. However, as we're discussing, mixing it with a near-transparent white (be it calcium carbonate, Baryte, calcium sulphate, etc) in different proportions solves most of these problems.

Hansa Yellows, on the other hand, have a very different lightfast rating ranging from one pigment manufacturer to another. The same pigment can be really permanent or very fugitive. Why that happens, exactly, I don't know, but this this clearly shows the differences between these two classes of pigments.

Jon
10-11-2013, 12:33 PM
Admin note: There may be some language difficulties in some of the communication going on in this thread and I have edited a few posts unrelated to the topic. Thank you for your understanding on this matter.

Back to topic:
Calcium Acetate a Lead White replacement?




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Gigalot
10-11-2013, 04:24 PM
A lot of geniuses used genuine Vremilion, Lead-Tin yellow oxide, Naples yellow, Orpiment, Green rat's poison, Red lead. But Paint manufacturers and government regulators do not agree with them and abandoned or prohibited some of our classic pigments :D
And we need to use some new, ordinary pigments to make compromise.

Lead white became rare and high cost pigment. Rembrandt's Lead white is an expensive thing. One genius used Rippolin, household paint. Not Tad Spurgeon, just Pablo. Tad used putty, titanium, lead, zinc, everything - all in one!