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Degreasing vs over drying/shrinkage

Discussion in 'Skulls and Skeletons' started by HuntersUnion, Feb 4, 2016.

  1. HuntersUnion

    HuntersUnion Member

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    Hi fellow skull cleaners,
    Anyone have any advice on how to fully degrease without over drying?

    I have an awesome degreasing tank to degrease 10 bear skulls at a time all in separate buckets of dawn water, 115-125 degrees. I have not kept track of the time they are taking, I am just watching the water and when the water stays clean for a week I remove the skull. I scrub the skull with a tooth brush and dawn, then air dry. This method is removing the grease very well but now I find the skulls are getting over dry and are opening up at the seams. Some skulls still have grease remaining in the stubborn spots but the rest of the skull looks very dry..... Is this just a preference thing, grease vs dry? I am starting to wonder if the perfectly degreased skull is just a myth..... And for scoring purposes should I be leaving some grease to avoid shrinkage? Any one having the same problem or can point me to a good discussion in the archives?

    Also I'd love to see pictures of others skulls so I can compare my finished products "level of greasiness". Anyone want to share or can point me to a good collection of photos?

    Thanks in advance :D
     
  2. 3bears

    3bears Well-Known Member

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    The skull will shrink when it dries, that is normal, a good method to use is zip ties, to hold things where they belong as they dry.
     

  3. Kurt27

    Kurt27 New Member

    I always will change out water 2-3 times, let dry completely, and then put it back in super hot water and scrub while using my air compressor to blow into the areas and the grease seams to really leach out. Could be my imagination....... But I think it helps.
     
  4. Sea Wolf

    Sea Wolf Well-Known Member

    Seams that open consistently the same way all the time, just use Zip ties as above while it is wet. Make them tight and it should dry just fine. There are even reuseable ones so you don't have to keep cutting them. 125 is high for bear. Bear fat melts out at a comfortably low temp unless your thermostat just wavers between the two when heating/cooling off. For the stubborn ones, let them have a time in straight ammonia (weeks) then try going back to the Dawn. I have also got a few I really got frustrated with and soaked them in acetone for a few months and then back into Dawn. I have a very old and poorly done Russian brown that is now soaking in ammonia and has been for at least 6 months now. I'll be pulling it soon to take a look. Was absolutely foul when I got it.
     
  5. HuntersUnion

    HuntersUnion Member

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    The tank will maintain what I set it to. It was running about 115 and I turned it up for the final week just because I'm impatient.
    Is there a down side of doing them hotter?
    Would you get book skulls scored prior to degreasing then?

    I'll have to try the zip ties, do you glue the seams then after whitening?

    oh so many questions..... I am so thankful for this forum ;)
     
  6. 3bears

    3bears Well-Known Member

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    I do glue them, but some will stay without it, once dry.
     
  7. Sea Wolf

    Sea Wolf Well-Known Member

    If something is loose, I generally glue it. The down side to a hotter temperature is possible bone damage. 120 works well for deer and they are usually done in a couple of weeks. For something like a bear that takes longer, soaking at a high temp can break down the bone structure. Bears and other greasy things just don't degrease on your schedule.

    As for book skulls, I would preferably beetle clean them, dry for the approved time frame and then get them scored. Cleaning can be done after that.

    Also don't fear the Advanced Search. Learn to use that and you will be reading forever.
     
  8. HuntersUnion

    HuntersUnion Member

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    Nothing happens on my schedule haha :'(

    I have spent many hours reading old posts and have gained a ton of info that way. There are a lot of different opinions and things seem to be evolving over the years. Sorry if my post was repetitive.

    Thanks for the help.

    Back to the degreasing, story of my life ;D
     
  9. HuntersUnion

    HuntersUnion Member

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    The bear your working on She Wolf, it was cleaned poorly before and now your redoing?

    Can you do this if he skull has a clear coat on it? I was thinking a soak in the acetone first to remove the finish. Then degrease as usual?????

    I was brought a really old polar bear but it has some kind of glue and clear coat on it. Owner says its from the 20s but I said no for fear of damaging it more than it already is.
     
  10. Sea Wolf

    Sea Wolf Well-Known Member

    Yes, the Russian bear was probably boiled and never really degreased. I should have taken pictures before I started. As for clear coat, acetone will remove most of them or soften others enough that you can peel it off. A whale skull I had was quite dirty and growing mold. I degreased it again and then into peroxide. It had a sealer on it that I did not remove. The degreasing seemed to go ok but when I put it into the peroxide, the coating bubbled up all over. Lots of blisters everywhere. As it dried, most of the blisters went back down. I simply rubbed the surface with acetone on a rag and everything is fine again.
     
  11. HuntersUnion

    HuntersUnion Member

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    Oh good to know. I would like to start redoing some of my first skulls but I clear coated them. Its water based, I imagine it will come off easy.
    My biggest struggle right now is keeping fish tank heaters running. They keep burning out. I don't feel safe running the bucket heater in my basement. With the awkward size and shape of the moose and caribou I'm working on it's the only method I've got. They barely get the water up to 115 and I have burnt out 3 since Nov :mad: Guess I better get the hubby on a "Caveman" set up.
    What a learning process, I am getting the hang of rotting off horns. Buffalo are next up for degreasing, should be fun.
    How long have you been cleaning skulls She Wolf?
     
  12. Sea Wolf

    Sea Wolf Well-Known Member

    For the fish tank heaters, some care is necessary. When you go to work with anything, unplug the heaters but do NOT remove them from the water. Wait for 15 min before you do. When you return them to the containers, wait 15 min before you plug them in. Also avoid cold water to start them in and allowing the water level to get too low. I have 10 Aqueon heaters now and I have only lost one. Another thing to watch for is that the element part of the heater isn't right up against anything under the surface. I have some older ones that I still use and they are at least 8 years old. I do not remember the brand but there is an outer shell of plastic/resin protecting the glass and they have held up well.

    Another thing you need to do is insulate your containers. Use anything you can find. Blankets, house insulation, bubble wrap, anything you can use to hold in the heat.
     
  13. HuntersUnion

    HuntersUnion Member

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    Ok I will start doing that with the heaters. Great to hear that they can last that long, I was ready to give up on that method.
    When I get some pictures on my computer I will post pics of my tank, I'm pretty proud of it and I haven't seen anyone do it the way I have.