Degreasing: Many people skip this step. You can produce a decent looking skull without it; however, proper degreasing ensures a whiter skull over time.
Building a degreasing tank: If you are looking for directions and pictures for building a degreasing tank, then scroll to the bottom of this page. There you can also find pictures for replacing a heating element and modifying its thermostat.
Full Degreasing:
(required for WHITE skulls that STAY WHITE):
This can be done with a five gallon bucket (insulated in winter) that can be heated between 115 and 130 degrees with a bucket heater on a timer. A bucket heater is a heating element on the end of a cord that you plug into an outlet or extension cord. They are used to keep livestock watering troughs ice free. The timer can be the regular timer you plug into an outlet and buy at places like Walmart.
It can also be done by installing a water heater element and lower
thermostat into the bottom of the bucket or other container. If this is a route you want to take,
then see directions below.
The drawback is that it takes about a month to degrease a deer. A third option
is to soak head in room-temperature ammonia for a couple weeks (I’ve not done
this). After burning up my bucket heater and going through several timers, I finally built the tank below. It is WAY better than the bucket heater method (although I think a bucket heater on a thermostat instead of a timer would work almost as well and minimize drilled holes)!
Speed Degreasing:
Relatively white skulls can be produced in this way. Grease may/will leach to the bone surface over time. Some skulls will remain nearly white with this process, other skulls will literally get pools of oil on their surface. Rinse out simmer pot, refill with clean water, and squirt in a generous amount of Dawn. Immerse your skull in it. Heat water to where it is almost too hot to put your fingers in, but not too hot to start simmering. This temperature would be over 130 degrees, and I’d estimate around 150 (below simmer temp). Let skull sit in this heated degreasing solution for about 6 hours, making sure that the water level doesn’t drop below the skull. When complete, thoroughly rinse off skull. How-to videos from sites like Elk101 and WhiteBoneCreations fall into a "speed degreasing on steroids" category in my opinion.
Degreasing soap and discoloration:
Several different types of soap degreaser have been tested by people, but the only one that shows consistent results without discoloring skulls is the clear Dawn. Blue Dawn is the runner up (I use it with good results). Other colors and brands can discolor skull. I've also used non-brand blue or clear Dawn-look-a-likes from WalMart with success. Objects that fall into degreaser, like leaves, or metal shavings, can discolor skull. Water with high iron content can also discolor skull.
Degreasing predator, varmint, and rodent skulls:
Bear, coyotes, wildcats, etc. can be placed in a ziplock with degreasing solution and floated in degrease tank with antlered skulls or placed in tank by themselves. I make sure they stay away from my element so the plastic doesn't get melted. Great care must be taken with teeth. Stubborn skulls like bear and wildcats may need soaking in acetone (not heated). Fully coating teeth that have dried slowly with polyurethane or another clear coat may possibly keep them from eventually cracking. Cracked teeth can be glued together on their edges with super glue or Elmers. Teeth can be glued in place with Elmers. Click here to be redirected to a page about a mountain lion skull I degreased.
2015 Update: I submersed deer skull (in middle of degreasing process) in bucket this fall, and then took my air compressor with blower nozzle and blasted every orifice of the skull under water. I even drilled a few strategic holes to allow air to enter some enclosed places. It blasted out some stubborn pieces of tissue/grease that I couldn't get out with water sprayer. I didn't damage any bones or nasals in the process. I don't think I could have done the same thing with a water power sprayer without damaging part of skull.
Semi-Professional De-greasing Tank:
This tank can hold ten gallons of water, which means I can submerge a bull elk, and a pronghorn at the same time. I use blue or clear Dawn dish soap. I don't measure, but I'd estimate about a 1/4 cup or more per 10 gallons. I wired a water heater thermostat and element to the tank using JB Weld to seal in the element and keep the thermostat tight to the tank. Thermostat also needs to be low enough that it won't be above the water if more water evaporates than you anticipate. This keeps my tank between 120 and 130 degrees fahrenheit constantly. I wrapped tank with some thin foam, and cover the top with bubble wrap around the elk antlers to keep in the heat and decrease evaporation. By wrapping my tank I can keep it at 125 degrees +/- 2 degrees. The soap water needs to be changed 2x to 1x per week. I monitor the water temp with a cooking thermometer until I find a good spot to leave my thermostat dial. On average, pronghorn and deer have taken 1.5 months, and elk about a month. All could be left in even longer to assure a top-notch degrease job.
2-15-13 Update
Working on an old pronghorn that has taken over 2 months now. Did a 5x5 elk that I degreased for a month+ but could have degrease another 1/2 month. Therefore I'd err on the side of 2 months average to fully degrease a skull. Ran my temps at 130 for a while, but have dropped it down to 120 or 125 as I may have been too hot.
11-18-14 New Degreasing Tank Build Pics.
This one does not throw my breaker.
Will hold two deer, an elk, and/or several pronghorn etc.
