Mesozoical Posted July 29, 2009 Share Posted July 29, 2009 So, I have a couple of limestone fossils that have some matrix attached that will not break off easily. I read that very diluted Hydrochloric acid is great for preparing fossils. Unfortunately, I do not have Hydrochloric acid. I was wondering if there are more common substitutes for Hydrochloric acid that I might keep at home. Thanks, Meso Link to comment Share on other sites More sharing options...
Irradiatus Posted July 29, 2009 Share Posted July 29, 2009 white vinegar I've used it on crinoidal limestone to great effect... It's usually about 5% acidic (or maybe 3 - don't remember) "The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be. " - Douglas Adams Link to comment Share on other sites More sharing options...
PaleoRon Posted July 29, 2009 Share Posted July 29, 2009 Muriatic acid is used to clean mortar from bricks. You should be able to get some at a larger hardware store. Use care and watch your fossil carefully or it will dissolve with the matrix. Link to comment Share on other sites More sharing options...
PaleoRon Posted July 29, 2009 Share Posted July 29, 2009 Acetic acid can be found at photography shops. It is basically super strength vinegar. Again, use caution and watch what you're working on. Read up on precautions about working with strong acids before using them and keep a neutralizer handy. Link to comment Share on other sites More sharing options...
Redlichia Posted July 29, 2009 Share Posted July 29, 2009 Muriatic acid is used to clean mortar from bricks. You should be able to get some at a larger hardware store. Use care and watch your fossil carefully or it will dissolve with the matrix. And outside house in a place aired!!! ->>>>> < Link to comment Share on other sites More sharing options...
Dave Bowen Posted July 29, 2009 Share Posted July 29, 2009 If you insist on HCl, you can get it at Autozone, Walmart, etc. It's battery acid. The container I use is a refill kit for a motorcycle battery. Dave Bowen Collin County, Texas. Paleontology: The next best thing to time travel. Link to comment Share on other sites More sharing options...
PaleoRon Posted July 29, 2009 Share Posted July 29, 2009 If you insist on HCl, you can get it at Autozone, Walmart, etc. It's battery acid. The container I use is a refill kit for a motorcycle battery. I believe battery acid is sulfuric. Much nastier than hydrochloric. Link to comment Share on other sites More sharing options...
fossilselachian Posted July 29, 2009 Share Posted July 29, 2009 If you insist on HCl, you can get it at Autozone, Walmart, etc. It's battery acid. The container I use is a refill kit for a motorcycle battery. I most certainly hope you are NOT using hydrochloric acid in you bike battery!!! As mentioned, battery acid is sulfuric acid. Link to comment Share on other sites More sharing options...
Auspex Posted July 29, 2009 Share Posted July 29, 2009 I believe battery acid is sulfuric. Much nastier than hydrochloric. Ditto that; it's B-A-D! Muriatic is dilute hydrochloric, and should be diluted further for your purpose. Even then, it can do more harm than good (to your fossils and to you). "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
MikeD Posted July 30, 2009 Share Posted July 30, 2009 And outside house in a place aired!!! Ha! I was going to say that. Also, acids can be dangerous and destructive. Be sure not to pour water into the acid to dilute it. It can result in a nasty heat reaction. Always pour acid into water. Start out weak and gradually get stronger. Be sure to neutralize the acid afterward and rinse, rinse, rinse. Any acid left on the matrix or fossil will continue to eat away at it. Link to comment Share on other sites More sharing options...
Guest solius symbiosus Posted July 30, 2009 Share Posted July 30, 2009 You should probably only be using HCl on silicified fossils. Link to comment Share on other sites More sharing options...
tracer Posted July 30, 2009 Share Posted July 30, 2009 So, I have a couple of limestone fossils that have some matrix attached here's the problem. if the fossils are really "limestone" (as in calcium carbonate), then likely so is the matrix, and so you can't chemically clean the matrix from the fossil in that they are made of the same thing. the only time something like a weak acid helps is when the material you want to keep is less affected by acid than what you want to get rid of. an example of that would be trying to use vinegar to remove a light coating of limey matrix from the test of an urchin. urchin tests are calcium carbonate too, but the most stable polymorph of it, calcite, and they therefore resist the acid better than the matrix does. but i pretty much never use chemicals to clean fossils. Link to comment Share on other sites More sharing options...
Dave Bowen Posted July 30, 2009 Share Posted July 30, 2009 Duh.... I knew that. I use sulfuric acid, not hydrochloric. It does soften the limestone pretty well, but as they have said, it will eat your fossil too. You have to be careful with it. And of course, take all of the other precautions as with working with any acid or caustic substance. Dave Bowen Collin County, Texas. Paleontology: The next best thing to time travel. Link to comment Share on other sites More sharing options...
Guest solius symbiosus Posted July 30, 2009 Share Posted July 30, 2009 I have never heard of anyone using sulfuric acid to prep. How well does it work? What is the process? Link to comment Share on other sites More sharing options...
ashcraft Posted July 30, 2009 Share Posted July 30, 2009 Have never used sulfuric on fossils, but it shold be similar to Hydrochloric, but be warned, sulfuric and hydrochloric are both strong acids (there are six total, meaning they completely lost their H+ in water), but sulfuric can be more concentrated because hydrochloric will only form a 30% solution, while sulfuric can be pure, and is known as oleum, and reaches about 120% solution because it potentially has 2 H+ it can lose. Oleum will explode on contact with water, and even battery acid, which I believe is around 30% sulfuric will cause water to boil when added. Of the two, I would use Hydrochloric acid, readily available at Lowe's, etc. as muriatic or mason's acid. Brent Ashcraft ashcraft, brent allen Link to comment Share on other sites More sharing options...
fosceal2 Posted July 31, 2009 Share Posted July 31, 2009 As a jeweler I have Aqua Regia at the store ( nitric acid and hydrochloric acid).... Way too strong even the 10kt, even when I try painting it on with a plastic bristle paint brush. I have also tried muriatic acid from Lowes. I am sure there are applications where it is useful but I find I can destroy my fossils during my prep just as well, and more safely for my family, with out it! Fosceal Link to comment Share on other sites More sharing options...
Mesozoical Posted July 31, 2009 Author Share Posted July 31, 2009 I tried the vinegar, and it worked pretty well. Thank you for the replies, everyone. Link to comment Share on other sites More sharing options...
ashcraft Posted July 31, 2009 Share Posted July 31, 2009 As a jeweler I have Aqua Regia at the store ( nitric acid and hydrochloric acid).... Way too strong even the 10kt, even when I try painting it on with a plastic bristle paint brush. I have also tried muriatic acid from Lowes. I am sure there are applications where it is useful but I find I can destroy my fossils during my prep just as well, and more safely for my family, with out it!Fosceal Aqua Regia is one of the few acids that will touch gold, and it will dissolve most metals. I have used it some in a previous job, and found that it actually dissolves metals such as copper slower then nitric acid by itself, or iron in hydrochloric acid by itself. Interestingly enough, nitric acid will not dissolve iron very well or quickly and hydrochloric is not too good on copper. Brent Ashcraft ashcraft, brent allen Link to comment Share on other sites More sharing options...
lawooten Posted August 3, 2009 Share Posted August 3, 2009 I have always used Muriatic acid also and it has worked very well. The best days are spent collecting fossils Link to comment Share on other sites More sharing options...
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