so! you'd like to clean some bones. there's a lot of different methods and opinions out there, and this guide is really only based off what I've done and had success with, so nothing I say is gospel! there's likely a few different products available in your country that aren't available in mine, so always have a look into these things before you start dunking your bones into buckets full of chemicals. now, with that out of the way, lets have a look into the process.
xx✸ [ prepping the three-step process ]
the first thing you're going to need if you want to clean bones is time and patience. the process is easy, but slow. depending on the state your bones are in and what animal they come from, some can take a matter of days to be cleaned and some can take up to months. there are three steps to cleaning bones: removing soft tissues, degreasing, and whitening. it's relatively easy to do all three of these steps, and my personal recommended equipment list is:
- gloves! and sanitizer for afterwards
- bucket or plastic bin with a lid
- scrubbing brush and toothbrush
- dish soap or other degreasing agent
- 6% or higher hydrogen peroxide
- pliers or tools for removing teeth
xx✸ [ step 1: removing soft tissues ]
there's a number of ways to do this, but it all depends heavily on how much space you have to work. some of the most common options are maceration, burying the bones, or keeping dermestid beetles. while the beetles are by far the fastest method to clean resudial tissue and skin off your bones, they do require large colonies to properly clear bones, which means keeping tanks with a certain level of heating, lighting, substrate, food, etc. this here is a wonderful resource for keeping dermestid beetles if that's something you would be interested in!
the remaining two options are rather slow, and each have their own pros and cons. burying them is easy if you have the ground space for it, however the smell may attract predators and scavengers, and there is a good chance your bones will be dug up and carried away. it's also quite a slow process, and tends to work better in some months than it does in others. as a general rule, the warmer the weather, the faster tissues will be able to decay. my personal method of choice is maceration. I find that this also helps loads with the degreasing process, as bacteria is cleaning it from the inside out.
xx✸ the maceration process
this process is notorious for smelling absolutely horrific, so I do not recommend this if you don't have somewhere far away from your house to do it. all you need to do is scrape as much flesh off the bones as you possibly can, fill a plastic bin or bucket up with enough tap water to cover the bones, and then fully submerge the bones in the tub. do not add any other chemicals to the water. this will not speed up your process, it will only kill off any bacteria that is necessary for the process. the bacteria from the bones will grow and begin to break down the tissues from the inside out. it's important to know that this works best in a warm environment, and at consistant temperatures - this can be achieved with heat mats or aquarium heaters, but personally, I just use a black bucket and leave it out in the sun during the entire process. about once a week, check in on your bones to see how they're going and to change the water. you will have a thick layer of absolutely foul smelling goop that builds up over time - this is good! this means it's working, however I usually tip this out and refill the bucket with tap water once a week. do not handle the maceration goop with bare hands, and absolutely do not handle it if you have cuts or wounds on your hands. this stuff is absolutely festering with bacteria, and can and will give you a nasty infection. i dispose of it at the back of my property in a hole, which i then bury to prevent any wildlife coming into contact with it.
you will know that your maceration is done when you notice they're flesh free, mostly white, and are no longer connected to each other by anything. i recommend using a strainer when changing the water, as this process does cause teeth to fall out of the skulls, which are very easily lost amongst the waste you're dumping. large fleshier, fattier animals will take longer to macerate, whereas smaller and more delicate animals are much faster. my fox skull took a few months, for example, whereas my bird skulls only took a week. they key to this step is patience and good preparation - and there's no downside to macerating them for too long! if you're unsure, just give them another week and try again. once you're happy with the bones, you can head onto degreasing!
| xx✸ [ step 2: degreasing ] degreasing bones is absolutely vital, as grease can sit deep in the bones for a long time before coming to the surface, and it will make your bones discoloured and stinky. grease usually looks like discoloured, waxy, yellowish brownish patches on bones. you can see an example of this on my goat skull to the right; the grease is those yellow patches around the eye socket, as well as the back of the skull. click the image to see the full view to see what I mean. this is a pretty similar method to the maceration, so if that's how you cleaned your bones in the first place, you can pretty much recycle your setup for this, too. this is the longest step in the bone cleaning process. there is no way to speed it up, unfortunately, and many of the cool bones that people like to collect come from big mammals, which are very fatty, and therefore their bones are very greasy. this is why I strongly recommend macerating bones over any other method, and to leave them cooking in there for longer than you think you need to. macerating cleans deeply, from the marrow to the outside, which drastically reduces grease. |  |
once again, there's a handful of ways you can degrease your bones. I personally haven't looked too deeply into the chemical methods - you can use both acetone, and ammonia to degrease, however you will need them in large quantities and I don't have any hardware stores that sell them in my area. I have heard that acetone does work the fastest, and ammonia is very effective, but I can't speak to that personally. however, if you'd like to look into those methods, this degreasing 101 guide might be perfect for you! what I have tried, and used on every single one of my bones so far, is the trusty old dish soap and water method. people online will specify that you need to use dawn dish soap, but that's not strictly true - you just need to find a colourless dish soap with degreasing properties. personally, I use the morning fresh lemon dish soap, since it's biodegradable, a strong degreaser, and it's yellow so it won't make my bones go any weird funky colours.
xx✸ the degreasing process
give your bucket from the maceration a good rinse and clean, and once again fill it up with tap water enough to fully submerge your bones. mix in as much dish soap as you feel like - there's not really a guide for this, I sort of just squeeze it in until it's nice and soapy. dunk your bones, seal the lid, and wait! this does work better when it's warm as well, but again, I just leave the tub in the sun. check in every week or so to see how things are going - there's a couple of ways to tell when the degreasing is working; once your water starts to turn cloudy and yellow-brownish, it's time to dump it and refill with fresh soap and water. you might also see clumps of fats or oils floating on the surface of the water as well, which also means it's time to refresh the water. repeat this process over and over until you go some time without seeing any further cloudiness or grease deposits in your water.
I recommend letting your bones fully dry out before you decide whether or not they've finished their degreasing. the water can make them appear darker, and you might miss a few spots before you head on over to the whitening process. I find the places that pesky stubborn grease likes to hide and linger is around and inside of the eye sockets, at the back base of the skull where it connects to the vertebre, and around the back molars, so make sure you take a good look in all of these places! I usually use this step to give the bones a good scrub with a scrub brush and use a toothbrush to get into those little places like the eye sockets, or in the actual cranium itself, and the holes where the teeth go. be gentle when you're scrubbing bones, particularly if it's a young animal. young animals won't have fully fused skeletons and a lot of the time, there will be plates and parts of the skull that are brittle and loose. and sometimes you'll need to repeat this step a few months or years down the line! it's likely you won't get all the grease out, especially in bigger animals. if you notice grease stains starting to show through after everything is done, simply repeat this process again until they're gone.
xx✸ [ step 3: bleaching and whitening ]
welcome to the final step! this is an optional step for some, especially if you like the natural colour of the bone. for me personally, I like to whiten up the bones just a little. I don't like blinding white, but I don't like the yellowish natural look either as it just makes me think they're a bit greasy and not quite clean enough to be displayed. it also has the added bonus of disinfecting, as hydrogen peroxide can kill off any lingering bacteria that might be sticking around. luckily, this step is super easy and you have a lot of control over how bleached you want the bones to be.
first things first: never use bleach products to whiten bones! yes, it will whiten them, but it will break down the structure of the bones and leave them brittle and liable to crumbling to dust in the future. I would never use anything other than diluted hydrogen peroxide, and I always have great success rates with it. my go-to is 6% hydrogen peroxide from the chemist, which I dilute about 40% peroxide and 60% water. you can get stronger concentrations, particularly in hair developer which can get you up to 12%. honestly though, after extending this much patience into the process so far, I don't find that it's really necessary to find an overly strong concentration. if you feel the 6% isn't enough, you can just use it straight! this is the shortest and easiest step in processing bones, and you can recycle your seup again to do it!
xx✸ the whitening process
get your tub, give it a good clean, and fill it with your peroxide dilution of choice. as I said, 40:60 ratio of 6% peroxide:water is my usual go-to. I have used this on freshly macerated and degreased bones, I've used it on dirty bones I've found in the bush, and on bones that have been bleaching in the sun for weeks. never fails me! I check in on the bones every 24hrs just to make sure they're not getting too white and shiny. your first dunk will likely result in a lot of foaming, cloudiness, and a very warm tub. this is normal; peroxide heats up when it's working and it will be working hard to dissolve away any remnants of tissue or other biological matter. it is also something that works better in heat, but do not leave peroxide in the sunlight unless you have a solid coloured tub to keep it in. it comes in dark brown bottles because it's sensitive to light, and having it out in the light will make it less effective. try wrapping it in a black bin liner if your tub is clear. once again, I never use any heaters for this process; it just gets left in the sun.
once the first round is complete, it's a good idea to let your bones sit in the sun while you refill your tub with new peroxide. the sunlight and warmth will keep the peroxide that's soaked into the bones active, and it will continue to work while it's sitting there. you can reuse peroxide quite a few times, provided you don't boil it - this will deactivate it and make it effectively useless. I only really dump the peroxide that I use for the initial bath, and then after that, I just let it sit in there for 24hrs, take it out and let it dry in the sun for a few hours to assess the colour, and then put it back in for another 24hrs if I think it needs to be lighter. this part is entirely up to you! and don't worry too much - if you don't like it a few days down the line and wish it was a little lighter, you can always re-bathe it in peroxide at a later date.
xx✸ [ final touches ]
with all this said and done, once your bones are clean and shiny, all that's really left is reassembling them for display! this is my favourite part - I love biology and I work in the vet industry, so I get to excersise my animal anatomy knowledge a bit for this. my tips for this are: teeth are tricky and it's hard to tell what goes where, but don't force them! just push until they fit, and if they don't fit then it probably isn't right. you can find dental charts for cats and dogs online that will probably help out with what the mouth is supposed to look like in similar animals if you're stuck. another thing I do straight away is glue in any loose parts of young animal bones. the nasal bones in particular are very prone to snapping off, as they're already thin and likely not fused in place on young animals.
enjoy your bones! I hope this article helps, feel free to drop me an email if you have any questions or want to talk about the process further. I also would be delighted to help you out in reassembling bones if you're stuck and can't find any other guides online! I also have a handy resources page for links to other people's cleaning guides, dental charts, and other handy information in regards to taxidermy :) happy bone hunting!