Wednesday, December 1, 2010

Opensource Solvent Gels in paleo

[Stupid, stupid, open access is what I meant, not open source. That's what happens with late night blog posting.]

I'd like to thank Randy Irmis for forwarding this paper to me last week, recently published in Palaeontologia Electronica. The technique described is a very interesting addition to the paleontology toolbox, and I look forward to experimenting with these materials soon. This is also an excellent example of a well-written methods paper, that clearly examines considerations for using these materials and also serves as a great example for preparators who might be looking for inspiration to publish their own take on techniques or tools (and a recommendation to look towards PE as a publishing venue). I'd be very interested to hear results if anyone else has used solvent gels or gives it a shot after reading!

When you peruse this paper, take special note of the attention paid to worker and specimen safety concerns. One part I particularly like is discussion about using judgment to determine whether or not attempts at reversing a treatment will cause more damage than it will undo. Also take a look at Figure 4.5 highlighting airscribe damage to the tooth surface.

Williams, Vincent S, Doyle, Adrian M., 2010. Cleaning Fossil Tooth Surfaces fro Microwear Analysis: Use of Solvent Gels to Remove
Resistant Consolidant. Palaeontologia Electronica Vol. 13, Issue 3; 2T:12p;
http://palaeo-electronica.org/2010_3/247/index.html

ABSTRACT
Fine-scale surface texture analysis of teeth has become increasingly useful for
anthropologists and palaeontologists to infer diet and jaw mechanics in fossil animals.
We describe a fast, non-abrasive and residue free method for the removal of resistant
consolidant from fossil teeth. The method utilises solvent gels, and its use is a significant
improvement over previous techniques, particularly where microwear analysis is
to be performed. The method adapts techniques originally developed by art conservators
for the removal of varnish from oil paintings without damaging the oil paint
beneath. A combination of Carbopol (a water soluble acrylic polymer) and Ethomeen
(a polyoxyethylene cocoamine detergent) allows solvents such as acetone and ethanol
to be suspended in a gel for application to consolidant coated tooth surfaces. Key
advantages are that dissolved consolidant is lifted away from the tooth surface into the
solvent gel and a high degree of control is possible such that small discrete areas can
be cleaned of consolidant. Because the solvents are held within a gel, cleaning of the
tooth surface can be performed without the need for a fume hood.

2 comments:

andrea t said...

hmm early morning posting is dangerous too, as i just posted something... in the wrong blog. more coffee is, as always, needed

wthompson said...

Thanks for this; I'll try it on some teeth I've had sitting awaiting something better like this. Hopefully they list where to obtain the materials...