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Cleaning PRESERVED specimens

Discussion in 'Skulls and Skeletons' started by AH7, Jul 10, 2012.

  1. AH7

    AH7 New Member

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    For all the hard-core experts (PA and Wouter - I'm talking to you!) and everyone else with experience, I have a tough question:

    We've talked in the past about cleaning preserved specimens (fluid fixed) and I've tried to convince people that they should avoid it at all costs: WAY too much work and not worth it. More cost effective to get fresh specimens than rescuing the odd preserved cat.

    However, I have a huge number of incredibly rare specimens that I have to clean (full skeletons), and they are in TERRIBLE shape. They were originally preserved decades ago (1950s and 1960s I think) with who knows what. Probably terrible things including, but not limited to, major carcinogens. Fun, right? It gets better!

    Many of these specimens were not maintained and completely dried out! So not only are they preserved, but their muscles are hard as a rock.

    I have used things like pliers of all kinds, wire cutters, serrated knives. I've soaked them in warm water (which helps a little), but no matter what I do, they take HOURS of HARD work by HAND. Those of you on here who know my preferred methods know that my modus is to go with the laziest method possible. I've used bugs and mostly macerate now, and don't care about how fast things go, but I would do ANYTHING to figure out an easier way to work on these specimens. I don't need them really super clean - not white, but defleshed and dry.

    Some of you museum people must have dealt with things like this before. Suggestions? My students (who undoubtedly will do most of the work when I get fed up) will thank you!
     
  2. thus-sung

    thus-sung New Member

    I've cleaned two fetal pig skulls (left over from a high school biology class) and they took absolutely FOREVER. I can't imagine having to do entire specimens.
     

  3. I've just cleaned a few old mummified bits up in the past, but ive had a lot of luck just adding some fabric softener to the maceration mix, makes them a bit slimy when you work on them, but really seems to soften up the connective tissues.
     
  4. Sea Wolf

    Sea Wolf Well-Known Member

    I had a dried up, mummified crane head that I worked on some time ago. It had been in formalin but the container leaked and all the liquid was lost. I think I remember soaking it in a solution of water, formaldehyde and sodium acetate. I don't remember the mix or even where I got the sodium acetate from.
     
  5. I posted a topic about this a while back and someone suggested that a protein in laundry soaps eat away at formalin. (I'm not good at chemistry) I don't know if that'll necessarily help your situation, but just a thought. Let me hunt down that tread for you.
     
  6. http://www.taxidermy.net/forum/index.php/topic,307142.0.html

    Thar she blows! Good luck!
     
  7. LordRusty

    LordRusty If I agreed with you, we'd both be wrong.

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    You can also try some of the softeners made for the Taxidermy trade. Knobloch's Kemal 4 and Knobloch's Enzol B immediately come to mind. Simply follow label directions ... especially with the Enzol B!

    The description for Enzol B reads: "This new "wonder-drug" for taxidermy tanning helps rehydrate raw skins (especially dried African skins). It helps degrease and remove blood from skin and hair, cleans hair, and breaks down non-tannable proteins. Tanned skins rehydrate in less than half the time, and ear cartilage is easier to remove. It also removes natural animal odors."

    I figure if it can rehydrate raw skins, it should work on anything 'raw' left on bones. I mean ... "breaks down non-tannable proteins" ... tells me it should break down the adhering muscle tissue fibers. Give it a shot. It shouldn't 'hurt' the bones ... just loosen up the fibers of the dried meat. ;)
     
  8. ravenswings1

    ravenswings1 New Member

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    Does not even sound worth it even if they are rare. Obviously the scientist or whatever that preserved them didn't care. I would fill up the jars with preservative and leave them. Can you share what kind of animals they are?
     
  9. LordRusty

    LordRusty If I agreed with you, we'd both be wrong.

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    It's worth it to whomever thinks these specimens are worth it. Obviously that's not you, but to Great Skulls, it is. It's all a matter of personal choice. ;) If I had a skeleton in my possession that was not fully cleaned, and even if the remaining flesh was like beef jerky ... and it was personally important to me ... yes, I would go through the trouble. Once you figure out how to do something, then doing it makes it worthwhile. ;D
     
  10. Maybe a generous amount of bromelain or papain added to your warm water bath, might help.
     
  11. AH7

    AH7 New Member

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    Trust me when I say that these are worth it! I haven't figured out exactly which specimens I'm starting with, but among there are Brachyteles, Cacajao, Tarsius and who knows what else. If any of you have skeletons of those sitting around that you'd let go legally for $200 (about what I'd say it's worth to deal with their mummified state), then I'll chuck these. However, I'm guessing most have not even heard of these no less owned them!

    The professor did care about them, he just had them in storage for a LONG time and as he got older, he could no longer take care of them. When he died, they went to a friend of mine (who doesn't clean bones), and now I'm trying to figure out what to do with them.

    Thanks for the advice. I'm nervous about introducing chemicals, but maybe I'll try the mix on some more common things like Saimiri - even though I'd hate to destroy even one of these too!
     
  12. LordRusty

    LordRusty If I agreed with you, we'd both be wrong.

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    Well, not being 'most' let me peel away the 'mystery'! ;)

    Brachyteles ... Woolly Spider Monkey
    [​IMG]

    Cacajao ... Uakari ... either Bald or Red Uakari, Black-headed, or the two others of the family.
    [​IMG]

    Tarsius ... of course is a genus of Tarsiers, small and totally adorable primates native to southeast Asia.
    This is the Pygmy Tarsier.
    [​IMG]

    I wouldn't worry much about using the Enzol B. As stated, it will soften raw skins, as well as raw flesh. I cannot imaging it damaging the bone. Just keep an eye on things ... checking frequently and hand working the flesh away as needed ... and you should be good to go. It will even soften the attaching cartilages making the skeleton easier to pose.
     
  13. ravenswings1

    ravenswings1 New Member

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    Even being mummified is very interesting, it is becoming more popular since the show Oddities came out. Some people build really beautiful custom stands for them to display them.

    http://ryanmatthewcohn.tumblr.com/

    [​IMG]

    Real human head:

    [​IMG]

    [​IMG]
     
  14. Sea Wolf

    Sea Wolf Well-Known Member

    That human head is pretty neat. Also looks to be very old.
     
  15. I was going to suggest protease treatment as well as I know some researchers who rely on them exclusively with good results. I'm wondering what makes you nervous, GS?
     
  16. lamina1982

    lamina1982 New Member

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    Why not just soak in water as long as takes to soften the flesh and then let the beetles do the rest of your work? Ive cleaned horse legs that were euthanised with pentobarbital and the bugs survived...so whats alil formaldehyde? lol...worth a shot anyways
     
  17. PA

    PA Well-Known Member

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    Sorry I am so late in answering but I have a few comments.

    In the early-1980's I was handed about 160 turtles that had been preserved in formalin and then dried out. I never knew if they had been transferred to alcohol before being dried or simply dried straight out. Probably it was as a result of fiber barrels which were the rage in the late 1960's through the 1970’s as a replacement for steel tanks - but they eventually rust out and leak fluid, allowing the specimens to dry out. And dry out these specimens did - they were so dry I could use the skin portion to drive a nail. They were lethal weapons when thrown with their sharp claws and such.

    There were about 8 species of turtles - all the common genera from Mississippi, Arkansas, Tennessee, Illinois and a couple other states. After lots of work I was able to make some reasonable skeletons from the collection, after trying lots of different methods.

    Initially I thought I could handle the carcasses with my dermestid colony. In my search of publications I found a paper published in 1951 by a preparator at the Field Museum:

    “de la Torre, L. 1951. A method for cleaning skulls of specimens preserved in alcohol. Journal of Mammalogy, 32:231-232.

    Abstract: Skulls are kept in running water for two days, dried for about an hour, brushed with liquid grease made of warmed bacon and beef fat, and force-fed to dermestids in jars or aquaria.”

    I didn’t use “liquid grease", but relaxed the tissue with water, sometimes added bouillon, or used ammonia, swelling the tissue and then cutting off the major tissue, again rinsing and feeding to the colony. I had some good success initially, but ultimately it took about as much volume in bugs as the tissue needing to be removed. e.g. if I had a cup worth of tissue remaining on an Apalone carcass, I would use about a cup of pure dermestid beetles and in a few days most the tissue would be removed. I did this about a month or so until I noticed that the dermestids no longer reproduced - even when given fresh bird, herp or mammal tissue. What essentially happened is that even though the bugs would consume meat from a formalin-fixed but rinsed carcass, and survive, they became sterile. The formalin/formaldehyde residue REALLY fixed the individuals like you would “fix” a dog or cat.

    So then I decided to go the chemical methods combined with hand cleaning. There had also been published literature about these methods:

    “Green, H. L. H. H. 1934. A rapid method of preparing clean bone specimens from fresh or fixed material. Anatomical Record, 61:1-3.

    Abstract: Describes the use of antiformin (composed of sodium carbonate, bleaching powder [sodium hypochlorite?], sodium hydroxide, and water). The author suggests caution to prevent damage to material, but insists that if carefully monitored, even small birds can be prepared perfectly.

    Harris, R. H. 1959. Small vertebrate skeletons. Museums Journal, 58:223-224.

    Abstract: Describes in detail the preparation of skeletal material by use of the enzymes pancreatin and papain and the macerator antiformin -- pancreatin for articulated skeletons, papain for complete disarticulation, and antiformin for material stored in alcohol or formaldehyde for a long time.

    Patterson, R., and B. H. Brattstrom. 1971. Preparing herp skeletons. American Biology Teacher, 33:554.

    Abstract: Minor note suggesting and describing how Biz and Clorox can be used to prepare skeletons from old formalin-preserved specimens of amphibians and reptiles.”

    So I proceeded to use various recipes of “antiformin” both heated and unheated, and using meat tenderizer which is a conglomeration of various enzymatic compounds like papain. Biz also contained some various enzymes like protease and oxygen cleaners like sodium perborate.

    Various experiments always ended up causing some damage to the bone material – more damage than I considered acceptable. I have always been of the opinion that the ultimate damage causing portion of these experiments was the element sodium. All forms of sodium seem to cause problems – sodium carbonate, sodium hydroxide, sodium hypochlorite, sodium perborate, etc. I believe the sodium is reacting with the calcium and replacing the ions in the chemical structure of the bone, ultimately degrading the bone flaking it away. Biz, in a later paper, causes even more damage and completely powders bone material years after the initial preparation. Materials at the USNM and elsewher cleaned that way never stood the test of time. It could be the sodium or the enzymes continue to cause problems.

    None of these methods ever produced really good quality specimens, and what I ultimately ended up doing was soaking them in multiple changes of ordinary clear ammonia like you would buy at a grocery store. Even though the pH of the ammonia is fairly high, I see no real damage to long-term storage of vertebrate bone material in ammonia. The procedure I would use would be to initially soak the turtle carcasses in 50% household ammonia diluted with tap water, and to soak the carcass for a week. The I would carve down and skin the carcass out as easily as possible using scaples , hemostats, pliers and tissue forceps. I would put in about a half hour, get most removed then add fresh 50% ammonia for another week and repeat as necessary. The once used ammonia could be used on new dried carcasses and repeatedly would relax the carcasses until spent.

    Very serviceable carcasses could be made of the turtle specimens, but certain problem areas never got truly clean. The tails of the Chelydra never could be cleaned well, and the feet still had tissue on them. But the long bones and shell often came out pretty good. The distortion of the shells also wasn’t quite as severe as in freshly prepped skeletons (differential shrinkage of the bone and the chitinous shell on it).

    Ammonia is a wonderful substance in working with bone material. It is able to dissolve out many lower melting point fats from within the bone without heating. Essentially all bird, reptile and fish fats are very low melting points (the actual fat melting point when rendered is much lower than in another post recently made – in my opinion). Mammal fats vary over a very wide range, but ammonia is almost useless on the tallow-like fat in cervids.

    Also, in my experience it does not damage bone material when kept at the concentrations obtained from the grocery store. A post doc working on finches years ago wished to remove the horny sheath off of various finch skulls. Sheaths of cardinals, bull finches, house finches are difficult to remove with traditional dermestid colony work unless maceration is used. However, maceration often puts the skulls into many small pieces. The best way to remove the bills is to first bug the bird skulls, then soak in ammonia for a period of time and the bill sheaths will eventually soften up and be able to be scraped off the bone with just a fingernail without doing any damage to the underlying bone. The skull will also still stay intact. Of course, any measurements on the bill should be made on the skull initially before removal.
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    In conclusion Great Skulls, ammonia soaks and hand cleaning would be the only way to go in my opinion. Water alone won’t relax a completely dried carcass, and maceration probably would not work as the smallest amount of residual formaldehyde residue will negate building a good maceration soup. I am hesitant to recommend various enzymes as I don’t have long experience with them combined with a long-term conservation study of how the specimens would hold up. I examined the shells and skeletons I prepped 29-30 years ago and they are still serviceable specimens.

    Good luck!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     
    Mr Clean likes this.
  18. AH7

    AH7 New Member

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    I knew you were the man PA.

    Thanks for the advice.

    I'll keep all of you in the loop on the progress. Should be interesting!
     
  19. Wouter

    Wouter Member

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    I just came back from holidays and read this post, very informative, especially PA's expert information. I myself use sometimes L10 maceration fluid to clean skulls that were preserved in alcohol or formalin, or from old mounts. It does work very well most of the time, but I also had a skull from an old mount crumble and I don't know why. It was a American Bittern, very hard to get in Holland and which is now no longer represented in my collection :'(. Therefore I'm hesitiant to recommend this stuff. Maybe if you try a small bone first.

    Wouter
     
  20. AH7

    AH7 New Member

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    Thanks for weighing in Wouter. Hope your vacation was relaxing and/or exciting. Find any new species for the collection?