Rosin Soap

[Absinthe]

I was reading through an old patent recipe for Fels Naptha Soap. The interesting things were that

1. they used caustic soda, potash and lime water as well
2. they used Rosin rather than plant oils or animal fats

I have a pine tar soap on my list for one of the next batches, but I can't seem to find any suggestions for using ROSIN. Now that baseball season is pretty much done, I can get rosin bags pretty cheap. Has anyone worked with this?

What is the benefit or reason to use Lime Water? Why would you want to use both Lye and Potash?

The ingredients follow:
(except for the potash the degrees represent specific gravity)

Naphtha at 65 deg (sg)
----100 gallons
Rosin
----750 lbs
Caustic Potash Disolved in Lime water and reduced to 60 degrees f
----100 lbs
Caustic Soda in solution at 38 degrees Baume (sg)
----100 lbs

Lime water = saturated calcium hydroxide
Potash = potassium hydroxide
Caustic Soda = sodium hydroxide

 

[Vintageliving]

A google search for "rosin in soapmaking" brought up several results. One of which was this, which states that rosin is similar to turpentine.

http://rsnz.natlib.govt.nz/volume/rsnz_ ... 05380.html

ETA: This article discusses both rosin and turpentine, and fascinating reading (Alas! only the first-page is free to read):

http://pubs.acs.org/doi/abs/10.1021/ie50153a008

In case someone wants to refer to the recipe, is this the one you were reading?

http://docs.google.com/gview?a=v&q=cach ... 2i4zKYTejA

This may be helpful:

http://books.google.com/books?id=UV8sWX ... 22&f=false

 

[Absinthe]

Yes that looks like the document I was reading, or at least the quoted recipe looks like it.

 

[Logansama]

A google search for "rosin in soapmaking" brought up several results. One of which was this, which states that rosin is similar to turpentine.



In case someone wants to refer to the recipe, is this the one you were reading?

http://docs.google.com/gview?a=v&q=cach ... 2i4zKYTejA

This may be helpful:

http://books.google.com/books?id=UV8sWX ... 22&f=false

The recipe came up as a bad link.

 

[DeeAnna]

While both come from the sap of pine trees, rosin is not the same as turpentine. When the pine sap is heated, turpentine is the light solvent that evaporates off the sap and is cooled and collected. Rosin is the heavier stuff that is left behind. Rosin is NOT the same as pine tar.

You can't convert old recipes directly into a modern CP or HP soap recipe, because the old recipes are based on the method of making a "boiled" soap with a lye and water excess.

I would also question the use of flammable naptha -- that isn't going to be a recipe for the faint of heart! But see this thread for a discussion of solvents in soap: http://www.soapmakingforum.com/showthread.php?t=45440

Other SMF threads on rosin in soap: https://www.google.com/search?q=ros...e=utf-8#q=rosin+soap+site:soapmakingforum.com