Skull Cleaning Tutorial

April 3, 2008

I used to throw away the raw skull from every critter I got in for
processing… what a waste, huh! The Native American in me would scream
with every good intact skull I tossed. Especially since so many people,
especially crafters and people with shelves for display items, love
skulls.

So here’s a little text-only tutorial.

What I do is this. Gloved-up, of course!

Tools I am working with: scalpel, steak knife, pair of forceps

First
I say thanks to the animal and it’s creator for the gift, then I decap,
then the eyes get plucked out. Then I work over the skull, incising and
removing the masseter muscle. I go in and remove the floor of the
mouth, and tongue. I am careful to make incisions on both sides of the
gum tissue so it can be peeled easily. I am careful to remove all the
meat inside the zygomatic arch, and under the occipital bulla. I scrape
the upper skull as clean as possible. Then I remove the lower jaw, peel
the upper skull’s palate, and scrape the lower jaw as clean as
possible, after picking off the muscle remnants. Lastly I take about a
12″ length of bailing wire, and immerse the skull in cold fresh water.
I put the bailing wire in to the brain cavity and gently stir and poke
the cavity all over. Then I gently shake the brains out through the
foramen magnum, in to the water. If any bits of brain are stuck, I
pluck them out through the foramen magnum with forceps.

Yes,
this is pretty gross. If you are weak-stomached, do not attempt this.
It too me 4 years to get up enough guts and tolerance to attempt this,
and I’ve been working with this kind of stuff almost 30 years. If you
think a cow or bear skull is going to be odorless after this kind of
cleaning, think again. This only works on coyote-size or smaller.

Once the skull has been cleaned, it is set in front of a warm forced air dryer.

This
results in an odorless & bone dry [har de har har] skull, ready for
the dermestid beetles, within about 12 hours. No chemicals are used.
Just plain elbow grease and water.

I’ve cleaned 2 complete
[legal] bird skeletons this way. Tonight I did the first [legal] mammal
bigger then a mouse. Came out super!

Many rogue taxidermists and some other types of people would display the skulls as-is, in this dried state.

Personally I don’t like skulls… I don’t display them at all.

The
reasons I clean them like this are, so they can make their way to new
homes after the appropriate swap… but in the meantime, they don’t
stink up the place! It adds a lot of value. It saves on shipping costs:
I don’t have to ship frozen. It speeds up the beetle time. The removal
of the brain makes degreasing the cranial vault much faster, and
lessens the chance of staining.

If you’ve seen the Dirty Jobs episode on Discovery with Skulls Unlimited in it… this processing is very similar to what they do. You could process your own and save some money.

Happy Processing!

Gwen, 2008

Addenda:

There is virtually no smell during the processing. I only work
on very fresh stuff – in all cases, it has been directly after I
finished skinning the still-half-frozen, not-yet-half-day-dead (fresher
then the meat in anyone’s freezer) critter. It’s just the eew factor
that gets to me. Maybe by the time I’m like 90 I’ll be able to do this
without being squeamish. Smiley

If
one were to try this on a slightly rotted skull, it would be *gross*. A
gas cartridge mask with paint/oil filters, and a fume hood, and/or a
mixture of baking soda, peroxide, and Dawn dish soap, will remove even
the toughest odor. The problem with rotting stuff is that the odor
clings and lingers (it gets in the air, and then in your hair) – if you
get even a drop on your clothes, you stink until they get taken off and
washed, and the odor is horrible.

To fully sterilize / clean a skull you have to do this:

1)
macerate (rot) all the flesh off, or have beetles eat the flesh off.
Maceration takes approx. 10 months, and beetles take approx. 2 days for
little skulls, or up to 2 weeks on big ones.
2) degrease the skull <– takes anywhere from 1-12 weeks
3) whiten the skull <– takes anywhere from 12 hours to over a week
4)
wash and rinse, then seal with an environmentally-stable sealant (such
as Mod Podge Matte). I like to leave my critter skulls in the sealant
for a few hours to let it really penetrate in to the bone. I then air
dry them, and re-apply sealant as needed until it looks good and
sealed, without looking plasticized or painted.
5) re-set /
re-implant all the sealed teeth. Sealing the teeth is very important as
it will prevent some enamel cracks from developing.
6) re-articulate the lower jaw to the upper

Then you can display it and be proud of the work.

Picture of some skulls pretty much ready for new homes (cleaned with the process described above):

Somewhere I remember someone saying something about certain soils or
outside conditions leaving indelible stains on skulls. I’m not talking
grease burn here… I mean some sort of iron oxide compound that won’t
peroxide, wash, or bleach out at all. Apparently it turns the skulls
either blackish, or greenish, or both. The only solution would be to
paint a skull that had that kind of stain. The risk of indelible
staining is almost nil in an indoor controlled environment. If it was a
common skull, like coon or opossum, it would be worth it to try, but
it’s not recommended for trying on a tiger.
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