From Skull to Showpiece: A Comprehensive Guide to Cleaning Bones

Cleaning bones is a fascinating process, whether you’re a budding osteologist, a dedicated collector, or simply curious about the natural world. Properly cleaned bones can be used for educational purposes, artistic endeavors, or even as unique decorative items. However, it’s crucial to understand the process thoroughly to avoid damaging the bone structure and ensure safety. This comprehensive guide will walk you through each step, from initial preparation to the final polish, providing detailed instructions and helpful tips.

Why Clean Bones?

Before diving into the process, it’s important to understand why cleaning bones is necessary. Fresh bones are covered in soft tissues, including muscle, ligaments, and tendons. These tissues not only obscure the bone’s natural beauty but also attract insects and bacteria, leading to unpleasant odors and potential health hazards. Cleaning removes these tissues, revealing the bone’s intricate structure and preserving it for long-term enjoyment. A well-cleaned bone is a testament to patience and attention to detail, showcasing the remarkable architecture hidden beneath layers of flesh.

Safety First: Essential Precautions

Working with animal remains requires taking necessary safety precautions. Always wear appropriate personal protective equipment (PPE), including:

* **Gloves:** Protect your hands from bacteria and potential contaminants. Nitrile or latex gloves are suitable.
* **Mask:** A dust mask or respirator is essential, especially when handling dried bones or using chemicals.
* **Eye Protection:** Safety glasses or goggles will prevent splashes from entering your eyes.
* **Ventilation:** Work in a well-ventilated area to avoid inhaling fumes from cleaning agents.

Furthermore, be mindful of the origin of the bones. If you suspect the animal died of a disease, take extra precautions to disinfect the bones thoroughly. Avoid cleaning bones from animals that may have been treated with poison or hazardous chemicals.

Step 1: Initial Preparation – Gathering Your Materials

Before you begin, gather all the necessary materials. Having everything on hand will streamline the process and prevent unnecessary interruptions. Here’s a checklist of essential supplies:

* **The Bone(s):** Obviously! Start with the bone you intend to clean.
* **Large Container(s):** Choose containers large enough to submerge the bone completely. Plastic tubs, buckets, or even old bathtubs can work, depending on the size of the specimen.
* **Water:** A readily available source of clean water is essential for soaking and rinsing.
* **Dish Soap:** A mild dish soap helps to remove grease and surface dirt.
* **Enzymatic Laundry Detergent (Optional):** Enzymes can aid in breaking down organic matter.
* **Ammonia (Optional, Use with Caution):** Ammonia is a powerful degreaser, but it should be used sparingly and with proper ventilation.
* **Hydrogen Peroxide (3% Solution):** Used for whitening the bones. Higher concentrations can damage the bone.
* **Soft-Bristled Brush:** A toothbrush or similar brush is ideal for scrubbing delicate areas.
* **Plastic Tools (Optional):** Plastic scrapers or dental picks can help remove stubborn tissues.
* **Mesh Bags (Optional):** Using mesh bags can help keep smaller bones together and prevent them from getting lost.
* **PPE:** Gloves, mask, and eye protection as described above.

Step 2: Defleshing – Removing Soft Tissues

Defleshing is the most crucial and often the most challenging step in the bone-cleaning process. The goal is to remove as much soft tissue as possible before moving on to degreasing and whitening. There are several methods for defleshing, each with its pros and cons:

* **Manual Removal:** This involves using tools like scalpels, knives, and tweezers to physically remove the flesh. It’s a labor-intensive process but offers the most control, minimizing the risk of damaging the bone. This method is best suited for smaller specimens or delicate bones.

* **How to:** Carefully cut away the muscle and connective tissues, working around joints and delicate areas. Be patient and methodical to avoid nicking or scratching the bone surface. Plastic tools are preferred over metal to prevent damage.

* **Maceration:** This involves soaking the bones in water to allow bacteria to decompose the soft tissues. It’s a natural process that requires little intervention, but it can be time-consuming and produce strong odors.

* **How to:** Place the bones in a container of water, ensuring they are completely submerged. Change the water every few days to prevent the buildup of foul odors and promote faster decomposition. Keep the container in a warm location (around 80-90°F) to accelerate the process. Be aware that maceration can cause bones to disarticulate, so consider using mesh bags to keep smaller bones together.

* **Simmering (Poaching):** Simmering the bones in water can help loosen the tissues, making them easier to remove. However, this method should be used with caution, as excessive heat can damage the bone structure, causing it to become brittle or even warp.

* **How to:** Place the bones in a pot of water and bring it to a gentle simmer. Do not boil the bones! Simmer for a few hours, checking periodically to see if the tissues are loosening. Once the tissues are soft, carefully remove the bones and use tools to scrape away the remaining flesh.

* **Important Note:** Never add bleach or other harsh chemicals to the water during simmering, as this can damage the bones and create toxic fumes.

* **Burial:** Burying the bones in the ground allows insects and microorganisms to naturally decompose the tissues. This is a hands-off method, but it can take several months or even years, depending on the climate and soil conditions. It can also be difficult to monitor the progress.

* **How to:** Dig a hole deep enough to completely bury the bones. Wrap the bones in mesh or cloth to prevent them from scattering and to protect them from excessive contact with soil. Mark the location of the burial site and check periodically for progress. Once the bones are clean, carefully excavate them and rinse them thoroughly.

The best method for defleshing depends on the size and condition of the bones, as well as your personal preferences and resources. For larger specimens, a combination of manual removal and maceration may be the most effective approach. For smaller, more delicate bones, manual removal or gentle simmering might be preferable.

Step 3: Degreasing – Removing Residual Fats

Once the majority of the soft tissues have been removed, the next step is degreasing. Bones contain fats that can leach out over time, causing them to discolor and develop an unpleasant odor. Degreasing removes these fats, ensuring the long-term preservation of the bones.

* **Dish Soap and Water:** This is a simple and effective method for removing surface grease. Soak the bones in a solution of warm water and dish soap for several weeks, changing the water regularly. The dish soap will help to emulsify the fats, allowing them to be washed away.

* **How to:** Fill a container with warm water and add a generous amount of dish soap. Submerge the bones completely and let them soak for several weeks, changing the water every few days or when it becomes cloudy. Use a soft-bristled brush to scrub the bones periodically to remove any accumulated grease.

* **Ammonia Soak (Use with Extreme Caution):** Ammonia is a powerful degreaser, but it must be used with caution due to its corrosive nature and potential health hazards. Always work in a well-ventilated area and wear appropriate PPE when handling ammonia. This method is generally reserved for bones that are heavily saturated with grease.

* **How to:** Dilute ammonia with water (a 10% solution is typically sufficient). Submerge the bones in the ammonia solution and let them soak for several weeks, changing the solution every few days. Monitor the bones closely, as prolonged exposure to ammonia can damage them. Once the bones are degreased, rinse them thoroughly with water to remove any residual ammonia.

* **Important Note:** Never mix ammonia with bleach, as this can create toxic and potentially fatal fumes.

* **Solvent Degreasing (For Advanced Users):** This method involves using solvents like acetone or mineral spirits to dissolve the fats. It’s a highly effective method, but it requires specialized equipment and knowledge due to the flammability and toxicity of the solvents. Solvent degreasing is typically performed in a laboratory setting.

The duration of the degreasing process depends on the size and type of bone, as well as the amount of grease present. Smaller bones may only require a few weeks of soaking, while larger, more porous bones may need several months. You’ll know the bones are adequately degreased when the water remains clear after soaking for several days.

Step 4: Whitening – Achieving a Pristine Finish

After defleshing and degreasing, the bones are ready for whitening. Whitening removes any remaining stains and gives the bones a clean, uniform appearance. The most common method for whitening bones is using hydrogen peroxide.

* **Hydrogen Peroxide Soak (3% Solution):** This is the safest and most widely recommended method for whitening bones. Use a 3% solution of hydrogen peroxide (the kind you find at the drugstore). Higher concentrations can damage the bone structure.

* **How to:** Fill a container with 3% hydrogen peroxide. Submerge the bones completely, ensuring they are not exposed to air. Let the bones soak for several days or weeks, checking periodically to monitor the whitening process. Change the hydrogen peroxide when it becomes cloudy or loses its effectiveness. The bones are adequately whitened when they reach the desired level of brightness.

* **Important Note:** Avoid using bleach (sodium hypochlorite) to whiten bones. Bleach can damage the bone structure and cause it to become brittle over time. It can also leave a yellow tint on the bones.

* **Sun Bleaching (Natural Whitening):** Exposing the bones to sunlight can also help to whiten them naturally. However, this method can be unpredictable and may take several weeks or months to achieve the desired results. It’s best suited for bones that have already been partially whitened with hydrogen peroxide.

* **How to:** Place the bones in a sunny location, turning them periodically to ensure even exposure. Protect the bones from rain and extreme temperatures. Monitor the bones closely to prevent over-bleaching or damage.

Step 5: Drying and Preservation – Ensuring Longevity

Once the bones have been whitened, it’s important to dry them properly to prevent mold growth and ensure their long-term preservation. Air drying is the preferred method.

* **Air Drying:** Place the bones in a well-ventilated area away from direct sunlight and heat. Allow them to dry slowly and naturally. This can take several days or weeks, depending on the size and thickness of the bones. Turning the bones periodically will help to ensure even drying.

* **Avoid Heat:** Do not use a hairdryer, oven, or other heat source to dry the bones, as this can cause them to crack or warp.

After the bones are completely dry, you can apply a consolidant to strengthen them and protect them from damage. Paraloid B-72 is a commonly used consolidant for bone preservation. Follow the manufacturer’s instructions for application.

Step 6: Articulation (Optional) – Reassembling the Skeleton

If you’re working with a complete skeleton, you may want to articulate the bones, reassembling them into their natural position. This is a complex process that requires patience, skill, and a good understanding of anatomy. Here are some tips for articulating bones:

* **Reference Materials:** Use anatomical charts, diagrams, and photographs to guide your articulation. Online resources and museum exhibits can also be helpful.
* **Adhesives:** Use a strong, flexible adhesive to bond the bones together. Epoxy resins or cyanoacrylate adhesives (super glue) are commonly used.
* **Wire and Support Structures:** Use wire or other support structures to reinforce the joints and prevent the skeleton from collapsing. Drill small holes in the bones to insert the wire.
* **Patience and Precision:** Articulation is a time-consuming process that requires patience and precision. Take your time and double-check your work to ensure accuracy.

Troubleshooting Common Problems

* **Persistent Odors:** If the bones still have an unpleasant odor after degreasing, try soaking them in a solution of baking soda and water.
* **Discoloration:** If the bones develop a yellow or brown tint, try soaking them in a fresh solution of hydrogen peroxide.
* **Brittle Bones:** If the bones become brittle, apply a consolidant to strengthen them.
* **Mold Growth:** If mold grows on the bones during drying, clean them with a solution of diluted vinegar or rubbing alcohol.

Ethical Considerations

It is crucial to acquire bones ethically and legally. Never collect bones from protected species or disturb archaeological sites. Obtain bones from reputable sources, such as roadkill, deceased pets (with owner’s permission), or ethically sourced specimens from museums or universities. Respect the animal from which the bones originated and handle them with care and reverence.

Conclusion

Cleaning bones is a rewarding process that allows you to connect with the natural world and appreciate the intricate beauty of skeletal structures. By following these detailed steps and taking necessary precautions, you can transform raw bones into stunning display pieces that will last for generations. Remember to be patient, meticulous, and respectful of the source material. With practice and dedication, you’ll become a master bone cleaner in no time! Good luck with your bone cleaning adventures!