Reckitt's Crown Blue

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Wancho

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Hi there,
I'm new to this forum, came here for a question.
I want to make blue colored soap.
The problem is that the usual blue colorants are not available where i live.
I did find small blocks of Reckitt's Crown Blue, normally used to make white clothes whiter while laundering (see attachment).
Here it is uused for voodoo and other superstitious stuff.
But i digress.
I read somewhere that the blue color in this product is obtained from (artificial) ultramarine, which is a suitable blue soap colorant.
I did search for an MSDS but to no avail.
I did put a small amount of it in a strong lye solution and it did not affect the blue color.
I also searched in the forums but found nothing.
Anyone familiar with this product and/or it's suitablitity as a blue soap dye?

Thanks!

Edit: made a test-batch, see results on page 3, post 21.

Reckitt.jpg
 
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You may not end up with blue but a pretty purple. I love bluing it will also help gray hair that is yellowing if it is in dilute liquid form. I am sure it is safe to use, just make a small batch and try it, but do not be suprised if it turns grayish, pinkish etc until the soap finishes saponifiying. I use blue food coloring often for purple, which starts out with an ugly gray, usually morphs into other colors before settling to lavender. Would be fun to see what color you end up with
 

Wancho

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Thank you for the reply Carolyn.
Purple will be no problem as it will be a lavender scented soap.
I also do not think it is unsafe, it is intended to be used on human clothing after all.
I guess i will just try it out this weekend.
I will report the results back.
 

Scooter

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Thank you for the reply Carolyn.
Purple will be no problem as it will be a lavender scented soap.
I also do not think it is unsafe, it is intended to be used on human clothing after all.
I guess i will just try it out this weekend.
I will report the results back.

Thanks for the information on Crown Blue. I am interested in how your experiment turns out.
 

Millie

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Hi Wancho, welcome to the forum!

I can't offer any advice on the Crown Blue in soap, but I found your post interesting - crown blue and voodoo! Tell us more, and share photos of your blue soaps. I wish you luck!
 

Wancho

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Hi Wancho, welcome to the forum!

I can't offer any advice on the Crown Blue in soap, but I found your post interesting - crown blue and voodoo! Tell us more, and share photos of your blue soaps. I wish you luck!

Thank you Millie,
About the voodoo part, i live on the island of Curaçao, it's an island in the caribbean sea and it is part of the kingdom of the Netherlands. The local people are quite superstitious, and these small blue cubes play a part in this. The most well-known superstitious use is on small babies. Whenever the baby is to leave the house, you swipe a little of it under one of your babies feet, then put on socks. It is supposed to ward off the evil eye. I am not superstitious myself, so apart from this i do not know what else they do with it and how, but i heard it was also used for more 'evil 'voodoo-ish purposes.

This weekend i will make a small test batch soap to see what happens. I will take pics and share them here on the forum.
 
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My brief research says that the product is copper sulfate and toxic, with most exposure being through the skin.
I have a feeling you did not look up laundry bluing which is a different from other bluings such as for steel. Mrs Stewarts bluing and Reckitts is ultramarine and baking soda. Mrs Stewarts has been used in the US since the late 1800's, and is still used as a pet and human hair safe. Reckitts is ultramarine and baking soda. Here is the link for msds of Mrs Stewarts Bluing http://mrsstewart.com/wp/wp-content/uploads/2016/05/MSB-SDS-061515.pdf
 
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DeeAnna

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My brief research says that the product is copper sulfate and toxic, with most exposure being through the skin.

Copper sulfate is indeed toxic, but from what I can discover the Crown Blue product was originally designed as a less toxic alternative to copper sulfate.

I cannot verify the formulation of the current product, but one formulation of Crown Blue was a blend of ultramarine blue and baking soda.

edit -- Carolyn beat me to the punch! :)
 
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Copper sulfate is indeed toxic, but from what I can discover the Crown Blue product was originally designed as a less toxic alternative to copper sulfate.

I cannot verify the formulation of the current product, but one formulation of Crown Blue was a blend of ultramarine blue and baking soda.

edit -- Carolyn beat me to the punch! :)
:) I also could not find current info for Reckitts. I still use Mrs Stewarts bluing. As far as I know, Steel bluing such as used in gun smithing is still toxic, but could have changed by now. Bluing became very popular during and after the depression as white hair rinse, when so many products were hard to get hold of. Forgot to add I still use it on my silver hair, it works better than rinses for white hair and my hair has no titch of yellowing from being in the sun.
 
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DeeAnna

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My first impression was copper sulfate too, so don't feel bad, TDG!
 

Wancho

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I'm pretty sure it is not copper sulfate because it stayed in solution after i added lye. If it were copper sulfate, a copper hydroxide precipitate would have formed. But thank you for your concern!
 

Scooter

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I cannot verify the formulation of the current product, but one formulation of Crown Blue was a blend of ultramarine blue and baking soda.

edit -- Carolyn beat me to the punch! :)

So the alkalinity of the baking soda would mean what for the fatty acid/NaOH reaction? Would it be necessary to add more fatty acids to counter it or is it too weak to matter?
 

kchaystack

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So the alkalinity of the baking soda would mean what for the fatty acid/NaOH reaction? Would it be necessary to add more fatty acids to counter it or is it too weak to matter?

It probably isn't going to be enough to make much of a difference - but technically it could saponify a small amount of fat and lower your superfat some.
 

Wancho

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It probably isn't going to be enough to make much of a difference - but technically it could saponify a small amount of fat and lower your superfat some.

Exactly. I might be needing a slightly higher superfat. But first i am going to find out how much of it is needed to achieve the desired color intensity. Who knows, maybe only a very small amount is needed to achieve the desired color intensity. If that is the case, then the effect of the sodium carbonate in the bluing agent can be considered negligible.
 

DeeAnna

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Baking soda = sodium BIcarbonate
Washing soda = sodium carbonate
 

Wancho

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Baking soda = sodium BIcarbonate
Washing soda = sodium carbonate

Thanks for pointing that out DeeAnna, i almost finished the academic study for pharmacist (i became a lawyer instead) but the name bicarbonate never made sense to me as there is only one (bi)carbonate ion for every sodium ion. So i stubbornly keep calling it sodium carbonate. In my opinion, washing soda should be called bisodium carbonate as there are two sodium ions for every (deprotonated) carbonic acid.

As wiki puts it: "The prefix, bi, in bicarbonate comes from an outdated naming system and is based on the observation that there is twice as much carbonate (CO3) per sodium in sodium bicarbonate (NaHCO3) as there is carbonate per sodium in sodium carbonate (Na2CO3) and other carbonates. The modern way of analyzing the situation based on the exact chemical composition (which was unknown when the name sodium bicarbonate was coined) says this the other way around: there is half as much sodium in NaHCO3 as in Na2CO3 (Na versus Na2)."

But for communicative purposes it would be better for me to be specific and say exactly what chemical compound i'm talking about.
 

DeeAnna

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"... But for communicative purposes it would be better for me to be specific and say exactly what chemical compound i'm talking about. ..."

Yes, it would. Chemistry has ancient origins as does the practice of law. We're stuck with the nomenclature in both fields.
 

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