Full Chisel Blog

June 18, 2010

Cooking Amber Resin

Filed under: Finishing,Historical Material,Of Interest,Techniques,Uncategorized — Stephen Shepherd @ 7:05 am

 

Amber (Succinite C40H64O4) is called a fossil resin but it has not been replaced with minerals it has just survived for tens of thousands to millions of years.  The sap from a variety of pine trees [Pinus spp.] that has oxygenated and hardened as all of its volatiles have since left, it is used for ornamentation, jewelry and smoking pipe stems, cigar and cigarette holders and other decorative items.  Called Electrum by the ancients it can take on an electrical charge by rubbing on cotton, silk or wool, a good test for real amber.  There is synthetic and imitation amber, real amber floats in sea water but has a higher specific gravity of 1.05 to 1.06,

Rubbing an amber bead on a silk handkerchief creates a static charge.

Small pieces of thin rice paper are attracted to the charged amber bead, this is a test for real amber.

It is also an ingredient the finest varnishes.  Vernice Martin is a mixture of copal and amber with linseed oil and spirits of turpentine, and amber is included in many recipes for musical instrument and furniture varnishes.  Generally amber needs to be cooked or melted at temperatures reportedly over 500 degrees F in order for it to be dissolved in linseed oil.  Some amber melts at just over 300 degrees and some will dissolve in alcohol or turpentine after just being ground fine.  It does not behave like other conifer resins.

I have noticed that when amber is dissolved in alcohol, not all of the resin goes into solution and what is left over [un-dissolved] and I dry this out then mix it with turpentine which dissolves most of the rest of the resin, some ‘foots’ remains.

You can see the conchoidal fracture on the half bead on the right.  The amber resin on the left has been cooked to 360 degrees [F] and ground before placing in alcohol.

Amber resin is commercially available from suppliers of traditional resins, incense, etc.  I have not yet tried any of these; I have made my own from some Amber that I have purchased including broken amber jewelry.   The example in the photographs are of amber beads that were on a stick pin that I got for a very reasonable price, therefore I decided to break one in half and cook up and grind it and it is now having a nice long soak in alcohol.  I will cook up the other half and mix it with turpentine.  I am also going to cook up a batch to dissolve in linseed oil.

These are just test batches so I can document the work in my next book.  I have discovered that some of the information that is currently available is incorrect, for instance the melting temperature of Burgundy Pitch is much lower than listed from most sources.  I also found out that a lot of information about various gums and resins is also lacking melting temperatures and solvents as well as other data.

Stephen

9 Comments »

  1. Stephen, I am researching natural resins for use as molding compounds. My interest is in a very early moldable compound called “mud” which is made of shellac and various low melting point resins. Would you mind sharing your melting point data for resins with me for my research? In particular, I am interested in melting temps between 170deg F to about 240deg F.

    Thanks! Michael

    Comment by Michael Hackney — November 15, 2010 @ 9:12 pm

  2. Michael,

    Welcome, and that information will be in my new book out probably late winter 2011. I can send you some information by email.

    Stephen

    Comment by Stephen Shepherd — November 16, 2010 @ 12:58 pm

  3. Hi Stephen

    Great website! I am interested in making amber varnish as well. Your comments on finely powdered amber dissolving in Alcohol or Turps is very helpful.

    Kremer Pigments in NY and Wood Finishing Supply Inc. (Google the website) both carry Amber. Dave at Woodfinisher’s is a real personable fellow, who has a good website with some recipes (But not amber recipies unfortunately),
    Kremer carries powdered amber, and I recently bought a pound.

    Thanks! Ron

    Comment by Ron Arrington — August 23, 2011 @ 11:44 pm

  4. Ron,
    Welcome and thanks. All of this an more is covered in my new book that is out on the market now. Shellac, Linseed Oil, & Paint-Traditional 19th Century Woodwork Finishes.

    Stephen

    Comment by Stephen Shepherd — August 24, 2011 @ 6:51 am

  5. […] stand corrected: http://www.fullchisel.com/blog/?p=1085 …..Learn new stuff every day. Still not sure about its use in a beer. __________________ MT […]

    Pingback by Amber ale with actual amber - Home Brew Forums — September 21, 2011 @ 12:19 pm

  6. Stephen,

    I have been reading this book called “The Philosophy of Taste” by Jean Anthelme Brillat-Savarin. He talks about amber-flavored chocolate which seemed intriguing to me. I have been trying to figure out if he truly meant the amber formed from tree sap or if there is another ingredient used in cooking under the name amber. I could not seem to find anything when I happened to come across this website that talks about dissolving it in alcohol. If you have any comments on this, please let me know.

    Thanks

    Comment by James — June 15, 2012 @ 10:59 pm

  7. James,
    I am sure it is amber resin, the stuff is used for incense and pipe stems, cigar and cigarette holders.
    Stephen

    Comment by Stephen Shepherd — June 16, 2012 @ 6:54 am

  8. I’m thinking of ways to restore the “black” backing on ambrotypes-photographs on glass.

    The dark varnish chips and cracks over time. I believe the varnish may have been made from amber dissolved in turpentine or linseed oil. I was going to experiment with damar varnish, but I think this may be the correct archival restoration. It is also possible that the varnish darkened further. Does anyone know what was used?

    Some backings look amber, some look red and are called ruby glass (I have seen actual red glass), although the ruby varnish gives the reddish glow most of the time. What could produce this red amber look?

    Comment by Dawn — May 20, 2014 @ 11:59 pm

  9. The Ambrotype was given its original name because amber-colored glass was used to produce a warmer-looking image. Ruby-red glass was also used for some photographs and “likenesses” for a classy (and more pricey) look.
    Pictures on glass, like Ambrotypes, are essentially thin negatives in which the bright areas are created by light reflecting off the dry emulsion, while the dark areas are created by “seeing through” the non-emulsion parts of the glass to the black background. To get the best contrast, the blackest backing was always preferred.
    Asphaltum Varnish produced the blackest coating on the non-emulsion side of the glass. Other Ambrotypes were backed with velvet, which eliminates the messy application of Asphaltum. The Ambrotypes I’ve made (including several of Mr. Shepherd) are backed with either black velvet or double-black art paper. If the emulsion is mounted facing the viewer, a cover glass should be used to protect the delicate surface.
    Tintypes were pre-blackened tin-plated sheet iron (using Asphaltum) in which the emulsion is applied to the blackened side of the plate. Very much cheaper to make.

    Comment by George Stapleford — May 21, 2014 @ 5:41 pm

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