Sponsored by the
Museum of Natural Science, Louisiana
State University
ABSORBENTS USED IN SKINNING
[Steve
Rogers:] These are the numbers from the questionnaire I circulated 25 years ago
but never got the chance to finish. 160+ preparators/collections contributed
information from almost every major collection in the world.
Study Skin Preparation
No.
2. "What absorbent for body fluids is used during skinning a bird
for a study skin?"
                                                                      US
Foreign Total
yellow
cornmeal                                               46
11 56
borax
                                          18
27 45
hardwood
sawdust                                            26
12 37
white
cornmeal                                
           28
4 31
potato
flour                                                
           1
20 21
softwood
sawdust                                
           4
14 18
magnesium
carbonate                                     3
14 17
plaster
of Paris                                              
-
2 2
none                                                              
-
2 2
unspecified
cornmeal                                      
1
1 2
talc                                                                 -
1 1
50%
hardwood sawdust:50% borax                  
-
2 2
50%
softwood sawdust:50% borax                   
-
1 1
75%
hardwood sawdust:25% borax                 
-
1 1
gypsum                                                          
-
1 1
50%
gypsum:50% potato flour                                  
-
1 1
borax
to plaster of Paris 2:3                            
-
1 1
ash
of rice hulls                                               -
1 1
flour                                                              
-
1 1
boric
acid + burnt alum                                    
           -
1 1
Zellstoff
(Cellucotton)                                                
-
1 1
laundry
soap                                                    
-
1 1
Furglow                                                          
1
- 1
Blue
Cloud chinchilla dusting powder                1
- 1
50%
yellow cornmeal:50% hardwood sawdust  
1
- 1
Calorax
(borax + alum)                                                1
- 1
cornmeal
+ ammonium alum mixed                  1
- 1
white
cornmeal/hardwood sawdust mixed         
1
- 1
2
parts white cornmeal/1 part boric acid         
1
1 1
Comments:
University of Arizona - I prefer white cornmeal for its
color and someone told me it contained less fat and oils than yellow.
Apply borax mainly to skull, base of tail, wing and leg bones.
San Diego Natural History Museum - Use yellow cornmeal,
after being thoroughly cleaned of the fine powder.
R. W. Dickerman - Never! use
borax.
North Carolina State Museum of Natural
History - We only use borax if slipping.
Vertebrate Museum, Shippensburg, Planz - Use cornmeal on
small birds because they dry out quickly if prepared using borax, but use borax
on all others.
Zoological Museum, University of Helsinki, Finland - We use
no absorbent because all birds are washed and impregnated with Eulan.
John G. Williams
- Usually I use heavy magnesium carbonate. Light magnesium carbonate is
useless forming a film over the plumage that is difficult to remove.
_______________________________________
I should also add - that we now use only ground corncobs in
skinning. We stopped using corn meal when we (and the mammal division) got a
Red-legged Flower Beetle infection in our collections. When we moved to the new
facility we chemically fumigated out entire collections in a huge space the
univ, had (an old garage), all nearly 120,000 specimens, in cases, doors off
and covered with acres of plastic. In the 8 or so years (I forget) since,
"birds" has had no subsequent infestations. We freeze everything that
comes from the prep room or via carrier.
The cob comes is several grinds. The finest works best, but creates
almost an aerosol, and as a safety measure we now use the next finest grind and
that works very well, both in skinning and in drying after washing, and blows
out well, even from the light under feathers. The next coarser grind works well
in a "tumbler" (wish we had one). I do not have the address at hand,
but will supply it to any who writes off line.
Bob Dickerman
______________________________________
Question: If powdered borax is carefully placed inside a skin before
completion and closing the incision, is foxing an issue? It certainly is if
used on the feathers etc. and I agree it should never be used and I do not use
it. I'm just curious because when I used to practice taxidermy as a hobby
some of us mixed borax with water and this paste was "painted" on the
inside of the skin or the powder was spread inside the skin only. Do commercial
taxidermists still use it?
Peter Capainolo
__________________________________________
Yes, commercial taxidermists still and only use borax. I am using
sawdust during skinning, and if bird is too fat, I just wash skin in detergent.
I don't put any chemicals to preserve skins. My taxi is using Eulan-not sure
what it is.
Best regards
Marko Rakovic
Natural History Museum of Belgrade
__________________________________________
Actually, I am not convinced that borax causes any
"foxing" in bird pigments any more than just regular oxidation of the
pigments themselves. I have never seen any real data on the subject, only
anecdotal evidence. Mammal pigments definitely are not set well and borax could
be involved, especially when washing the skin in a borax solution as Leon Pray
advocated in his early taxidermy manuals. This method was generally the method
early taxidermists in North America learned from the old J. W. Elwood
Northwestern School of Taxidermy out of Omaha Nebraska. You can wash a red
squirrel in a Calorax solution and see the red pigment wash out.
In my opinion, Borax is only a bad chemical if it hasn't been sifted
to remove the extremely fine dust, as it can gather into the vane-let spaces
and cause a white cast as Janet mentioned.
Corncob dust is sold by a few Taxidermy Supply companies and comes
in quite a number of grit sizes. They primarily use it in tumblers. There are
numerous industrial uses of the dust and it is probably cheaper to just buy
from one of the industrial companies. For example:
http://stutzcompany.thomasnet.com/viewitems/corn-cob-grit-products/grit-
o-cobs-reg-corncob-granules?&forward=1
http://ntruddockcompany.thomasnet.com/viewitems/abrasives-media/grit-o-c
ob-reg-?&forward=1
[Steve Rogers]
_____________________________________________________
[Bob Dickerman]: As far as I know there is no empirical evidence
that borax effects color. ARP believed it, and I follow! I dislike the stuff
anyway!
A note from Claudia Angle, Collections Manager for USGS at USNM
gives some evidence regarding borax caused foxing.
"Long ago...Roxie Laybourne showed me a series of thrush
skins...and asked me to pick out those that were different. ALL of the
"different" skins were Burleigh's. Roxie claimed that was because he
used Borax and that it effects the red pigments." [NOTE - I would
suggest it was the melanin pigments that were effected]
______________________________________________________
When I learned to skin we used magnesium carbonate, but I have used
only cornmeal for a long time. I think the magnesium carbonate or other fine
white powders might be hard to get all out of the feathers, which might affect
the color, leaving a whitish cast. The cornmeal blows out well and doesn't
stick. The sawdust I have tried was very hard to get out of the down feathers,
but different kinds might be different in this respect. I try to not leave too
much cornmeal in the skin, and never felt that this was what attracted bugs.
The worst problem we have had with bugs was with flat grebe skins, and the bugs
could get directly at the greasy skin. In spite of scraping and washing with
Stoddard Solvent 3 times they still left a greasy mark on the paper after a few
years.
Janet Hinshaw
Bird Division Collection Manager
Museum of Zoology
University of Michigan
_____________________________________
Hi Janet and all-
At 10:02 AM 10/16/2009, Janet Hinshaw wrote:
When I learned to skin we used magnesium carbonate,
but I have used only cornmeal for a long time. I think the magnesium carbonate
or other fine white powders might be hard to get all out of the feathers, which
might affect the color, leaving a whitish cast.
That's because you were not using mag carb HEAVY.  The right stuff is amazing. It falls
out of feathers completely  and does not
leave a whitish residue. It will dry-to-fluffiness  a small skin that has been washed with
detergent and
rinsed, ... in seconds. No drastic procedures like
tumbling,  or compressed air are needed,
although I did use a hair drier  on cool
from a distance to make double sure all of it was  removed, and to "arranged" the
feathers. Ask Andy Williams,  Manuel
Marin, maybe Mark Robbins, and Mark Holmgren too,  just how amazing.
Blue Cloud is almost as fast and it is easier to find.   It is a finely milled volcanic "rock"
if I remember correctly.  Most of it
falls out of feathers easily. To completely remove  any dust caught in barbules, put the
skin in a dry container  (cardboard box
will do), shake a few seconds, remove, and 
blow gently with a cool hair drier.
Either mag carb heavy or Blue Cloud will cut cleaning time  significantly, and minimize trauma to
feathers.
Sam Sumida, Avinet
_______________________________________________
The supplier for cob fines is Mt. Pulaski Products in Mt. Pulaski
IL. They're on the web. Call them up, they're fairly used to museums wanting
their products in small quantities now. You can get it in ca. 50-pound bags.
The 80/100 is best (everything that falls thru a #80 screen but rests on a #100
screen), just a little finer than most cornmeal, but a lot more absorbent.
their finest grade is called 'flour' ,I think, and is too fine, it creates
major dust problems as you use it, especially if used by students who are just
learning to skin.
30/60 is the grade that's a bit coarser. It'd be good in a tumbler,
but I'm not sure that it's so much better than 80/100 to warrant getting 2
grades, unless you have a major project skinning waterfowl or larids or
something.
Best,
Andy Johnson
________________________________
Matt Miller:
Corncob dust can be purchased from Van Dykes
They call it tumbling mix. Their coarse #1 is really coarse...too
coarse for all but the largest birds. Their #4 is right on for most birds.
Winker/UAM would mix the #4 with even a finer dust for small birds (chickadees,
hummers, etc.), but I can't find a good supplier for that. We just use the #4.
Comes in 50-pound lot for 26 bucks plus shipping. I can't imagine that you can
buy 50 lbs. of corn meal for 26 bucks, and I certainly wouldn't want to use
corn meal on birds down here in Panama. The dust is superior to cornmeal for
soaking up fat and blood too (in my experience).
And Van Dyke's must be easy to order from, because I've successfully
received a couple shipments despite STRI's super-arcane purchasing labyrinth.
__________________________________
[Kevin Winker]: We learned of the wonders of cob flour and Mt.
Pulaski Products from S. Peter Getman in the 1980s at the Bell Museum. (Anybody
have contact information for Pete?) We prefer 30/80 and find the finer grades
too fine (you inhale too much and can get a dust cough). As I recall, you can
request a sample of different grades before investing in 50 lb. bags. (I
remember the first time I called and they wondered how many tons we wanted; the
bag sent said something like "0.025 tons".)
______________________________
One thing to note is that some people have slight to bad allergic
reactions to corncob dust. Usually when people first start using it they
sneeze, get stuffy noses, and/or watery eyes. Be mindful of this
and warn first time users. I've outgrown most my reaction to the corncob
dust.
Despite this, I have grown to like corncob dust over the other
alternatives that I have used. It's absorbent, blows out of the feathers
easily, and is light for transporting in to the field. Cornmeal is just too
course for small birds and definitely isn't as absorbent. (I also find it
a bit oily) Sawdust tends to stick in the down of certain birds, especially
owls and hawks. Other alternatives are heavy and sometimes much more expensive.
The corncob flour was mentioned as being too fine for general use. I
agree. However, I love it to dry small birds that need to be
washed. Just put this flour in a bag or Tupperware container with the
bird and shake. Works just as well as chinchilla dust and isn't as heavy.
It is best to blow the flour out under a fume hood.
Brian K. Schmidt
Smithsonian Institution, Div. of Birds