I have searched the archives etc. and for degreasing skulls and such it seems like dawn dishwashing detergent keeps coming up. I find it hard to believe that a dishwashing soap you can put your hands in will do as good a job as acetone or something similar. I'm giving it a shot but I'm skeptical. Can anyone convince me that it's going to work and how long should I keep it in a strong dawn solution if it's going to? Thanks.
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Dawn works great for cutting grease. It is a soap and that is what it is formulated to do. I don't know that it works any better than the cheaper dishwashing soaps, but it does stay sudsly longer.
Acetone, on the other hand does absolutely nothing for cutting grease.
Jon
You're using a solvent in acetone, and besides it being highly flammable to the point of explosiveness, it only dissolves the oil. Soap actually breaks the oil down so that it can be rinsed away. Your acetone will always leave its own residue.
I've used both with success.... solvents can do wonderful jobs on cutting grease and leave no residue behind. Some of the most potent grease cutters are highly toxic and used strictly under quality control situations in museums (stuff that taxidermists will likely never have access to) and it is solvent based. Soaps do work as well however and simply cut grease in a different way. I have been leaning towards soap based products lately partly because of the lower toxicity, but more so because I cannot legally use solvents in the volumes I require. Dawn detergent over the course of 1 - 4 weeks will handle most jobs. Exceptionally greasy beasts may take longer and a water change or two to get the desired results.
When grease is broken down in solvents the grease settles out to the bottom. When grease is broken down in soaps it is coated and floats to the top. No product magically makes the grease disappear, they just move it to different places within the solution.
Hope that helps =)
Raven, after seeing your post, it makes considerably more sense to me now. I have always just assumed that Solvents didn't do anything for grease as (Yes i know I am bad George) I soak my bird skins in acetone to displace the water. Well I can always tell if my skin is clean or not, cause the fat tends to clump in the acetone and there are actually two parts.. one heavier part that sinks to the bottom, and then a thin skin that forms on top of the liquid. Whenever this happens, I almost always have to go rewash my skin as there is no way to get the skin out of the acetone without the grease collecting on the feathers somewhere... which of course is a bad thing.
Ya learn sumtin new everyday!
Have a good one!
Jon~
I find that the solvents often get far deeper into the bone than the soapy solutions. I'll often combine techniques to get maximum effectiveness; a degreasing in solvent solution, then a scrub in warm soapy water to remove any minor surface oils that may remain. Even if I soak in soapy solutions - I still do a final surface scrub (when you pick up the skull from the solution you have to pass it through that oily film on top of the soapy water). By combining you get the deep cleaning of solvent, plus the final surface prep of soap.
And as an ammendment to my above comment that nothing makes oils disappear... I was referring to this in the degreasing stage only, as the maceration technique will break down some of the oils. They are digested by bacteria and are obliterated, not just moved from one place to another. The longer maceration is allowed to continue, the more thorough the digestion of oils. It's faster to degrease than to macerate to remove oils, but I find the maceration does give the degreasing a head start.
Sorry Dale - I tend to ramble quite often.
Short Answer - yes, dawn detergent will work. Make sure it's clear so it doesnt tint the bone some funky colour. Rittels Super Solvent is another soapy solution that works very well.
That was good EXCEPT for the part about "solvents leave no residue". That's bullsh1t and you should know that EVERYTHING leaves some sort of residue. As I've told others, Just place a drop of gasoline , acetone, and lacquer thinner on a clean sheet of typing paper and let it dry. Then hold it up to the light. THEN make that same statement as to why those stains are on the paper.
Exclude acetone from your list of materials there George ;) I have never ever recommended using gasoline or anything of that nature to degrease. Acetone - yes. Other solvents which aren't even widely available and are highly toxic - yes, though only under controlled situations. Gasoline, turpentine etc - no way.
I did your test with acetone. Heres what I did and the results I found. and how much residue was left on the paper? I poured a wee capful of acetone over a sheet of paper - it took about 20 seconds for the liquid to absorb/evaporate to a damp state... and at that point it looked like it had the oil residue that you get when greasy food sits on unwaxed paper for example. BUT - 20 seconds after that when the acetone had fully evaporated, not one trace of residue or any indication of where my acetone was. Not even when held up to the light. I'm smelling my paper as I type this sentence.. and I can't even smell a hint of acetone on it. It is 100% gone.
Like I said - acetone removes the grease from the bone and that grease settles out into the bottom - it does not remain in suspended solution. The only thing you need to worry about is that the bone may still have oily residue on the bottom portions of it.. but again - a quick scrub when you pull it out and yer worries are over. Keep in mind that the amount of grease and oil in skull isn't measured in cups or quarts... we're talking teaspoons... a couple teaspoons of oil in a skull will look like hell when it leaches out to the surface, but as a thin film on the bottom of a container of acetone? Neglegable.
Now a test for you... put a cup of acetone into a clear container then add a cap full of vegetable oil. This is probably more than the amount of oil in a typical deer skull for example depending on how large your cap is. You will see it immediately sink to the bottom - sort of look murky and swirly for a minute then it starts to settle out. Given enough time it becomes a thin film that covers just the bottom of the container like an oily dish in a sinkful of nasty dishwater... nothing to worry about. The only concern I would have is disturbing the acetone when removing the skull and kicking up that oily layer that has settled out of solution. A quick scrub will clean any of that bit up. And again - if you use soap - you still need to do a scrub as you are pulling the skull up through the oily film on top. Always give a scrub under warm running water wish a lil soap to finish your degreasing.
One more lil thing... Im an artist/technician of sorts by trade, but a biologist by educational background. I'm not a chemist, however, BIOchemistry does come in to play a little bit.. very little - and less whenever I can help it ;)
Acetone contains hydrocarbons as does gas etc; but is defined as a ketone. Ketones are actually bi-products of fat digestion (oils and grease etc) in a biological organism. In fact - diabetics and dieters can monitor ketones in their urine during a phase called 'ketosis' to measure the level of fat they are burning. Acetone can be found in urine and even detected on the breath of some diabetics in certain chemically unbalanced states.. it is naturally occuring but can also be manufactured in industrial situations. It is not refined petroleum as is gasoline etc as far as I am aware. Just being a solvent doesn't mean it's oily. H2O is a solvent afterall and obviously has no oil or residue.
So anyway - I think maybe the confusion here lies in the fact that acetone, being that it contains a hydrocarbon group is being related to other hydrocarbon compounds like gasoline, when in fact it is a bi-product of the break down OF those compounds, and thus not one of those compounds itself. It could be that you knew enough to question the logic, but not enough to answer the question. I'm not saying thats bad or mean it any derogatory way, I think it's awesome that someone clued into the hydrocarbon thing at all. I had forgotten about it and I PAID MONEY to learn the stuff - LOL! On the surface it does make sense that it could be lumped in with other solvents that leave oily residues, but digging deeper specifically into what acetone and ketones are I think clarifies it.. I hope...
Whoa - my head hurts. Too many flashbacks to chem class.... Ow.
Just had an idea for a custom degreasing tank. If you use solvents, put a lift in the bottom to raise the osteo materials out of the oily layer. A metal frame welded or bolted together with hardware cloth over that should be sufficient. remove the solvent periodically to within a couple inches of the bottom - then PROPERLY dispose of that last couple inch layer and you can theoretically reclaim a large portion of your solvent! I'm getting all excited now - LOL! I should look into drycleaning set ups for more ideas. They use solvents like TCE (again - obviously no residue here or you'd get oily blotches on all your dry cleaned clothes). I wonder what sort of set ups they have and what tricks we can learn from them... hrmmm
I knew how to spell chemistry pretty well myself, Raven, and like the laws of physics, they ain't changing cause you want them to. LOL. You'll just have to get over it. It's still and always will be a SOLVENT. Solvents dissolve, Alkali's eliminate.
*I* have to get over it? LOL!
I just explained some of the differences between solvents like gas and solvents like acetone. Detergents move the oils up, and proper solvents move the oils down. As I stated above - a process has to happen to break oils down into ketones for them to be truly eliminated and detergents do not do this. Bacetria and enzymes do - not detergents which is simple a 'surfactant'. I did your little test with the acetone on paper and there was zero residue when you claimed there would be marks. I charge that you have never DONE your own acetone on paper test and just ASSUMED it would generate your supposed results based on your BELIEF that acetone is a solvent in the same group as gasoline. Or perhaps you used nail polish remover which *contains* acetone but is *not* acetone. It has oils etc in it to aid in the moisturizing of keratin which may leave the marks you claim will be present.
Since they stopped using mercury, the entire dry cleaning industry is based on using solvents to clean clothes - yet clothes don't come back from there oily now do they, George? You are stuck in the belief that all solvents are the same when flat out they are not. Some solvents (like those I recommend) are very effective at removing grease and are the degreasers of choice in dry cleaning and industrial applications around the world and also used in museum and university applications to degrease osteological specimens. Yet once again - you seem to be limited by it's applications as they pertain to taxidermy and fail to see how common solvents as a degreaser truly are.
I dont know how you can debate this when I explained how acetone is a KETONE.. and is thus NOT an oil - but a bi product of the break down OF oils.
I think anyone reading this in the archives will see the points I have proven and realize that yes it does work based on chemistry - not "no it doesn't work" based on opinion and stubborn beliefs and set ways. It is for the beneift of those readers that I make this post - not to further dispute the matter with you. I guess thats the glory of being set in your ways - you've earned the right to ignore reality to support your claims... I can't compete with that. If all the facts I laid out generates a response of simply "it's still a solvent" as the basis for your argument then we are at a dead end. Yes it is a solvent. No it is not the same type of residue leaving solvent that gasoline is. Water and rubbing alcohol are solvents too - I guess by all your comments and logic, water leaves oily residue behind as well? You always have and likely always will believe that acetone doesn't work for degreasing skulls and that it will leave oily residue. If you can't see the differences between types of solvents then there's no point in discussing this further.
No hard feelings - I still think you rock and will be amongst the guys backing you up when people say yer an a$s - LOL! See ya 'round the forums ;)