Friday, May 15, 2015

BONELUST Q&A: "I've been macerating bones & they are now a strange color! Are they ruined?"

Maceration is the process of purification to remove the remaining flesh from bone. It is the easiest & least expensive way to do this while still leaving bones in good condition. Note that this process is typically best for animals larger than a rat. Smaller bones can turn to mush during maceration as they themselves start to break down.

To macerate you take your animal remains that have very minimal flesh on them (never a whole animal!), add them to a plastic container & fill with plain tap water then replace the tight fitted lid. The lid is important because you don't want insect larvae in your maceration water only the bacteria that will grow and eat away the flesh. You also don't want to leave it out in the rain without a lid or you'll get algae growing. Insect larvae & algae with both start to break down and possibly even stain the bone.

The more flesh on the remains the longer this process will take. Somewhere around 2 weeks the bones should be coated with a film that's pink, red, rust, brown or black. That's normal & means the bacteria is working to remove the flesh. The bacteria may however be dead now though so time to change the water if still fleshy and start the process again, or time to start peroxide bath if done. Pour out only half on the nasty water and add fresh water to fill the rest of the container if the maceration is not done yet.


These deer bones were covered with a bright red film because they were left for too long in the maceration process, on accident. They were completely flesh free though. Thankfully I just hosed the film right off then started the peroxide step to get rid of the awful smell.

The odd colored film you see on your bones is a residue of the bacteria or the bacteria itself coating the bone. It does this when the water runs out of oxygen for the bacteria to survive. Referred to as the bacteria going anaerobic. This anaerobic bacteria in maceration replaces the microbes that were doing the maceration work of defleshing the bones. And therefore the maceration process has come to a halt.

It can be caused by too many microbes using up all of the oxygen in the water or it can be from an oily film on top of the water that keeps oxygen from entering the water. Some ways to prevent this are - larger quantities of water, changing the water or a bubbler. It commonly happens to marine mammal remains during maceration because of the high oil content in their bones rising to the top of the water.


This is a potbelly pig skull that started off lightly mummified that soaked undisturbed for 2 weeks. The maceration water was still fairly clear and yet the skull was turning black. I've found that when there is little flesh to work with or very old flesh this can happen. Sometimes the black film easily hoses off or goes away once the bone dries. In this case though it took a peroxide bath to remove the black coloration. 



Raccoon bone that was pulled out of maceration. It was dropped into peroxide and pulled out an hour later to show how fast the peroxide can get rid of the staining. It can in most cases happen instantly.


"Before" of diamondback rattlesnake bones straight out of maceration.


"After" of same diamondback rattlesnake bones after a peroxide bath.

The maceration water needs to be kept at a certain temp to work. It will not work in the Winter in most locations because it is too cold for the bacteria to survive. It will also die off if it gets too hot in warmer months. For exact temperatures & more extensive info about this see this blogspot blog.

Good luck!

Saturday, March 21, 2015

BONELUST Q&A: "What's this white stuff on my bones? How do I get rid of it?"

What you are seeing here on this rabbit skull is called adipocere AKA corpse wax, grave wax or mortuary wax. It is a crumbly, waxy, water-insoluble material consisting mostly of saturated fatty acids.  

BONELUST Q&A: "What's this white stuff on my bones? How do I get rid of it?" What you are seeing here on this rabbit skull is called adipocere AKA corpse wax, grave wax or mortuary wax.

Adipocere is the product of a chemical reaction in which fats react with water and hydrogen in the presence of bacterial enzymes, breaking down into fatty acids and soaps. Adipocere is resistant to bacteria and can protect a corpse, slowing further decomposition. The transformation of fats into adipocere occurs best in an environment that has an absence of oxygen and high levels of moisture. Adipocere formation begins within a month of death, and, in the absence of air, it can persist for centuries.

It is not uncommon for adipocere to be found on bones. Either found in a natural setting or while being processed. I've found that the best time to remove it is either A) when the bones are freshly out of maceration or peroxide and you use a toothbrush to literally brush the adipocere off while submerged in water or B) After the bones have been degreased, had a peroxide bath and then dried. The adipocere become less waxy and more flaky and you can more easily remove it with your fingernail or again, with a toothbrush. This time dry.

Be careful how much force you use on a bone with a brush or fingernail. This rabbit skull for example is going to be a real challenge for me to remove the adipocere as it is a very thin/fragile skull.  

Friday, March 20, 2015

BONELUST Q&A: "The teeth fell out of my skull! Did I do something wrong? How do I fix it?"

It is absolutely normal for some of the teeth to fall out of a skull you are processing. The gums that once held them in place are now gone. It is also normal for the mandible to split into two pieces in many animals, like this coyote.

BONELUST PERSONAL COLLECTION: Here's that same coyote skull I posted a while ago that someone glued the skull & mandible together with an awful brown glue. It only took a few days soaking in a peroxide bath to pop it off & for the mandible to come back ap

Take photos of the skull/head with teeth in place before starting to clean it if you think you will have trouble putting them back into the correct place.

BONELUST Q&A: "The teeth fell out of my skull! Did I do something wrong? How do I fix it?" It is absolutely normal for some of the teeth to fall out of a skull you are processing. The gums that once held them in place are now gone. It is also normal for t

Pictured above is what you do NOT want to do! I received this absolutely glue saturated opossum skull from someone I though would know better. Second photo shows the same glue (white) before I brushed it off with a toothbrush, after I soaked the whole skull in water to remove the glue. Not all glues will come off in water but I suggest that as your first try.

Followup with a peroxide bath overnight. Then dry. Next you put the teeth back into place one by one with a very small amount of white school glue on each root before inserting into the skull. Wipe off any excess glue or it will be shiny on your skull. Let dry upside down so the teeth stay in place.

You put the mandibles back together with a small about of white school glue as well. They will not stay in place while drying without some help. I have a blog post already on how to reattach a mandible. 

BONELUST Q&A: "How do I put mandibles back together?" There are many ways to reattach two mandible halves that have come apart. Depends on the species. I prefer to use regular white school glue because you don't always get it right first time around. It i

Some animal skulls you can flip over and the freshly lightly glued mandible just stays nicely in place while drying. Also, by doing it that way you're sure you have them glued together at the right angle.

BONELUST Q&A: "How do I put mandibles back together & teeth back into a skull?" There are many ways to reattach two mandible halves that have come apart. Depends on the species. I prefer to use regular white school glue because you don't always get it rig