The finishing.com Hotline: Serious Education ... plus the most fun you can have in metal finishing. Ted Mooney, Webmaster
Preparing sea shells for crafts or display
Q. I've read comments about polishing/cleaning sea shells including "buffing" with a material from a lapidary supplier. I'm trying to clean numerous shells, many are fragile (mussels, moonshells, etc.) and I know they would not do well in a tumbler. Could you comment about how to use the "chemical" in a hands-on approach?
It appears that the surface of our shells is calcium, salt, etc. We can purchase commercial sea shells that are cleaned to the natural color, but we want to clean the ones we find.
- Nanaimo, BC, Canada
In addition to selling chemicals to the metals industry, I am a seashell collector. We collect and clean thousands of seashells. If you want to discuss this further, I suggest that you
There really are not people on this forum that have chemicals for cleaning shells. It depends a lot on what you plan to do with the seashells and what you want them to look like. Normal shell cleaning consists of descaling with diluted bleach, followed by cleaning and then putting a light mineral oil or similar material on the surface to bring out the color. Other chemical cleaning is usually injurious to the surface.
Stellar Solutions, Inc.
Q. I'm an art therapist, and didn't care much about sea shells till now. 4 months ago I started a treatment with a child of 10 years old, and the only way to start a dialogue with him was by sea shells. So I began to collect them, to read books about them - because this child asks many questions about them - and was fascinated with this new world. He himself started his own collection. Our question is: how come the shells that we buy are so bright and "clean"? is there any way we can do it in my clinic? I appreciate your reply, thanks.Aliza Galkin
art therapist - Moshav Amikam, D. N. Menashe, Israel
A. The reason that the shell you buy are bright and shiny is probably because (depending on the species) it was collected live and still in good condition. After a shell has been on the beach for awhile it very quickly erodes and loses its luster. If the shell is shiny inside but not on the outside it could be coated with deposits that can be removed with bleach or similar material, then coated with a light mineral oil or baby oil to bring out the colors. It is often necessary to pick off thick deposits or remove them ultrasonically.
Stellar Solutions, Inc.
Diamond drills for beach glass and sea shells
Q. Well, I too have recently returned from the Bahamas and we found a conch shell while snorkeling. We have gotten the meat removed, while in Bahamas, and a local told me to soak it in water and bleach... most of the debris are gone but it now has a white film on it. What do I do next to finish cleaning it?Brian Peterson
army - Fayetteville, North Carolina
Q. I have been trying to find out how to polish sea shells. I have read various sites where it is suggested that you use a tumbler. I did not want to invest that much money into the effort. I was told that once the shell was soaked in diluted bleach water, I could polish it with a rag and car compound, and then to seal it with clear fingernail polish. Has anyone used this technique and how has it worked?Linda Riley
- Virginia Beach, Virginia
A. I've also been experimenting with sea shell cleaning. I discovered the film left on the shell from the bleach, so I soaked one type, an oyster shell, in vinegar for a short period and it turned out great!Chris Feemster
- Port Orchard, Washington
Smithsonian Handbooks: Shells
Q. I have tried the mineral oil on my shells with good results initially but after the oil soaks in, the color turns back the way it was. Which is a whitish color. Is there something else I could use that would not soak in as much? Or do I need to soak longer in vinegar or bleach?Criss Helms
- Capitola, California
Q. I have oyster shells that I would like to re-use in cooking: for various dishes served on the half shell, so I'm trying to get them as odor-free as possible. So far I've scrubbed them with salt and vinegar, boiled them, soaked them in vinegar water, scrubbed with baking soda [linked by editor to product info at Amazon]. They still have an odor. If I bleach them, will they still be usable as food containers? Has anyone else done this?Carolyn V Jones
- Baltimore, Maryland
Q. I am making crafts using shells. They have rust on them. Can you please tell me how to remove the rust and how to add luster to the shell?Anit [last name deleted for privacy by Editor]
- Hamilton, Ontario, Canada
A. I collect fresh water muscles to use the shells in jewelry making and carving. I have a method of cleaning and polishing that works very well, but it is time consuming and a bit of a chore. And I have heard a method that I will explain and then hopefully try when I get the materials. With the river or clam shells I clean then as well as I can with soap and water. Then I usually use a Dremel [linked by editor to product info at Amazon] to cut them into the shape I want. After that I use 600 grit waterproof sandpaper to polish the outside and inside of the shell. I polish or sand them underwater and this works very good to bring out the shine. After they are smoothed by the sandpaper I take a dremel buffing pad and some jewelers rough(very little as it can stain the mother of pearl. And buff it to a very high gloss finish. This brings out more color than you would ever imagine there was in a simple river clam shell. But it does take a toll on your fingers. Another method I've heard involves Muriatic Acid [linked by editor to product info at Amazon] -- The kind of stuff you get to clean your cement floors prior to sealing them...Garages and stuff. You use rubber protective gloves [linked by editor to product info at Amazon] and dip the shell in the acid. The acid quickly eats away anything on the surface of the shell. A few seconds for smaller shells would be more than enough. This is how they get abalone so shiny so it should work on other shells as well. Rinse thoroughly with tap water and rub thoroughly with a towel it should be nice and shiny....However I have not tried this yet so do not do it if your shell is precious or a great find try it on broken not so perfect shells first something you would not be disappointed to lose. I intend to try this the next time I get to the department store. Good luck if you beat me to it.Michael D Stoner
- Sioux Falls, South Dakota
Q. I have collected several shells, from the Great Lakes. I wanted to try to make into jewelry, but don't think they can handle a tumbler. How do you polish them.Kristi Loving
- Redford, Michigan
May 12, 2008
Q. While vacationing in St Lucia, we purchased a freshly caught conch from a beach vendor.
The meat had already been removed, and he descaled it for us, but it needs to be deodorized.
I have had it soaking in, first, clean water, and then switched over to baking soda in the water in an effort to rid it of the smell, but to no avail as yet.
Can anyone please recommend the best way to de-stink the shell?
If bleach is to be used, what is the best measurement to observe?
Thanks in advance!
- Burlington, Ontario, Canada
September 18, 2008
A. We have found from the locals here on the Island the best way to rid a shell of the smell is to place it by an ant hill and the ants will eat any remnants left in the shell. Our conch shells come back from the ant hills odor free and ready for the shelf.Greg Snider
- Isla Mujeres, Mexico
September 21, 2008
Q. I have several sea oyster shells that I am wondering how to not only get the smell out of them, but, to also get the beautiful mother of pearl. I have soaked them in bleach water now twice, but, they still have the smell. How do I get the outside of the shell off without ruining the mother of pearl?Kathy Sevilla
- Clinchco, Virginia
November 24, 2008
A. You must be very careful using muriatic acid to clean your shells, as it will dissolve them if left in it for very long.
You must dunk the shells in then take it out and rinse in clean water and do this until the desired affect is reached. Real thin shells will dissolve very quickly. Soaking in 50/50 bleach water for 24 hours will remove most stains and disinfect the shells, then rinse well in clear water, then use Lime-away and a scrub brush to finish cleaning. A very high polish can be achieved by using a fine grade of waterproof sandpaper and sanding under water.
- Dome Valley, Arizona
March 9, 2010
A. Hi there, according to what I have read dilute ammonia is the way to go to clean shells especially to take the brown outside off pearl shells. I have just found a gorgeous woven island clutch bag decorated with a cleaned abalone. It is stunning.
Before you could go to the shop and buy ammonia, urine, animal or human, was the substance of choice.
This free substance was also incredibly useful in other processes such as dyeing. Dilute ammonia and certain types of lichen produce stunning dyes.
- Sydney NSW Australia
July 11, 2010
A. I have made several pieces of art work with shells and the quickest, cheapest and successful I have been at making shells shiny is by using Silicone Spray which you can purchased at a hardware store for about $5 per can.
I hope this helps
- New Zealand
March 17, 2013
Q. I have a giant Tridacna shell that needs some attention. I'm not concerned with the exterior, but would like to clean and polish the interior. It's too large to hold up to a buffing wheel. It has possibilities to be quite handsome if it were cleaned and polished. All I've ever done to it is wash with a dilute bleach/water solution, and a stiff brush. It looks clean, but is kind of dull.Gary Miller
Hobbyist - Ilwaco, Washington, USA
A. Good day Gary.
I have no idea what a Tridacna sea shell looks like, I'm sure it must be impressive, because you see the beauty of it.
You might try a very fine pumice with water to remove any rough features, a good water rinse, and apply a clear lacquer or similar to give the porous surface a sleek finish, thereby giving it some measure of reflectivity.
I tried to preserve corals myself while snorkeling in the Caribbean, and after cleaning, drying (removing the live organism itself), these corals today are quite impressive.
Hope this helps.
- Toronto, Ontario, Canada
A. I'm going to guess that you want to polish the thing to a high shine. I'd suggest wet sanding with 500-800 grit and work down in grits to 1200-2000. Then use an automotive buffing wheel with a very fine polish (5 Micron alumina and diatomaceous earth would be my suggestion, mix in a 2:5 ratio with water).Marc Banks
Blacksmith - Boone, North Carolina, USA
December 14, 2014
A. If you are looking to remove the crust that forms on Sea shells, use a wire brush attachment on a Dremel. Finish with a coat of mineral oil.
You should know I am not a professional but I bring home shells every year from Florida and this works well with conchs.
- Richmond Hill, Georgia, USA
April 26, 2015
Q. Hello, I want to decalcify mussel shells to flatten them to make lamps. Does anyone know how to do this?Kay Hampton
- Timmins, Ontario, Canada
A. I found some conch shells on Anna Maria Island. They looked faded and had barnacles all over them. I simply picked the barnacles off with a fingernail wood stick. Then dip them in a solution 1 part muriatic acid to 4 parts water. Stir for about 5 seconds then immediately dip into cool water. Set them out to dry. After they dried I rubbed them with mineral oil and they looked beautiful!!! With my other shells I've found, for example scallop shells, I pick barnacles off, if any, and then I buff the surfaces with a fingernail buffer. After that, I polish them with a clear coat of fingernail polish and set to dry. Some shells I've found have needed some extra attention. Specifically ones with really rough edges or even slightly broken shells. To fix them I bought a Pedi-file (as seen on TV). It's an electric nail file basically, but it works well for shaping and smoothing shells. After filing I always coat my shells with mineral oil, baby oil, or a clear coat of nail polish. Hope this helps!Amanda Pacetti
- St. Augustine, Florida, USA
June 3, 2015
Came upon this site looking for a way to polish a shell I purchased from a black pearl dealer in Polynesia. I also snorkel and scuba dive as a hobby. I got some great ideas here but am appalled at some posts. One should not take living Coral or Conch's from the sea!! The oceans and their denizens are in great peril.
They do not need to be further damaged by unknowledgeable, periodic interlopers. Do not touch anything with bare hands either.
- Shawnee Mission, Kansas, USA
Hi Kathy. True enough. Nature has been here for billions of years and will be here for billions more; but if we make the world non-habitable for us, we won't be :-(
There are twice as many people on the planet as when I was a kid, and even then some resources were exhausted without us being fully conscious of it. What was thought to be harmless then, as being just a drop of water in an endless sea, is now recognized as problematical. By the time you are a senior, the world may have decided that all snorkeling and scuba diving is harmful.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
April 11, 2016
A. I have collected many shells so I've been testing ways to bring back shine. I've found washing with bleach, peroxide, baking soda, whichever you find best to clean/deodorize shells. Some needed soaking 24 hours or longer. I've not ever had a smell problem. Unfortunately coming home with a hermit crab does happen. He will die fairly quickly without salt water. I soak them in bleachy water and have my husband pull the dead animal out or you can place shell in pot of water bring to boil and the tissue will boil out. Ants doing the job would work great if you don't mind waiting. After drying, rubbing with an oil is essential for colors to return and make it shine. I've used my face cleaning oil with coconut and Aragon oils as well as Palmers oil...works awesome! Usually 24-48 hours later I paint polyurethane on them. Not just to make them extra shining but tough. They don't feel so fragile and will last years.Shannon Stinson
- Freeport, Florida USA
June 3, 2016
!! That thing that some of you are referring to as "meat", isn't just "meat"! It is a live animal body. It is so so so cruel to me when I think that we human beings are so selfish that would go intrude into these animals habitats by diving or snorkeling, collect those living animals, kill them and remove them from their shells and then polish them to decorate our house or sell them for sake of some money.
I understand that the live shells are not comparable to the dead ones in how nice they look, but same applies to humans as well!
- Dublin, Ireland
Hi Neeku. It has always been a dog-eat-dog world, and I can't ethically fault people who eat conch instead of chicken if they believe that animal protein is necessary for their own and their children's survival. The same with aborigines who used conch shells as horns for vital communications, or for garment buttons.
But times are always changing, and moral beliefs evolve with them. Today we lead lives of leisure and freedom-from-want to such an extent that new moral questions come hot and heavy, like whether conch shells should even be used as decorations :-)
Personally, I believe that deferring to the "feelings" of living things must be proportionate to their level of consciousness ... otherwise how do you justify killing a tick to keep it from infecting a dog, or swatting a biting fly that is driving a helpless horse mad, or protecting our bodies from mosquitos or our homes from termites? I believe that love of animals is a wonderful thing -- up to but never including the point where it is used as a justification or excuse for misanthropy, because people are the most conscious form of life that we know of :-)
Ted Mooney, P.E. RET
Pine Beach, New Jersey
June 16, 2016
Q. Have read with interest how to clean up shells. Am hoping that the conch dweller "meat" was actually eaten and not discarded, as waste not want not etc. Can anyone help with removing a horrid bright yellow stain from a large vintage mother of pearl bead ? It's from about the 1930's and is lovely apart from this awful stain that looks like dye. The nacre is a beautiful creamy natural colour and I don't want to bleach the bead white. Any help greatly appreciated. Thanks, JulesJules Cooper
- London England UK
June 27, 2016
!! My schooling and love of my life has always been Marine Biology. I dove in most of the recognized sites worldwide and many many more of the unknown sites.
Cleaning a shelled invertebrate [salt water] that has recently been fished for food is easily done with 50/50 fresh water and bleach. It will take a couple days to get the smell out but be patient. Rushing it with muriatic acid is an incorrect path to take. Using a brush or pick after the shell has soaked is ok.
Personally, I don't condone the taking of live sea life unless used for food. Conch btw is quite good. There are plenty of shells recently discarded by local fisherman providing an abundance of shells for the collector. The only concession you must make is dealing with the small hole at the crown of the Conch, where the animal was removed.
After at most one week, the smell should be gone. The ant solution was a new one to me but quite logical. Thanks for the info.
To polish the mother of pearl layer I use 2000-4000 grit wet sandpaper and bring up the shine gently. Again patience is the key. Any organic oil that you would use on your body will bring back the gloss. I would not seal this layer with any inorganic solution like poly or lacquer. Regular oil maintenance similar to furniture care is sufficient.
To finish the outer layer is another matter, a wheel with finishing compound is a good method. Soaking the outside with your chosen interior oil will help.
I think it generous of people to post their solutions; however, taking live coral from the ocean is something to be embarrassed about.
The whiteing out of much of the world's reefs is a serious problem. A coral has a very narrow life support range in terms of temperature and salinity. Merely touching the exoskeleton (your collection) with a bare finger will kill the animal inside the skeleton. To give you a shot at developing an appreciation go on a midnight reef dive on a coral reef. When you see the abundance of fragile coral extended, waving in the ebb and flow and exposed, an impression should be made upon you. One that turns you into a protector instead of bone collector.
It's never too late to learn and pass it on. Good luck on your collecting and showcasing but please make as small of a footprint as possible when visiting the UW world.
Marine Biologist, PADI DCD retired
training - Henderson, Nevada