chiefjim
off to a rocking start
Member since November 2009
Posts: 12
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Post by chiefjim on Nov 24, 2009 1:31:19 GMT -5
I have several large abalone shells that are very rough and pitted on the outer shell. I would like to get rid of the nasty and polish up the shells down to the color. I could grind off the rough on the wheel grinder, but I really don't want the dust in the shop. (Abalone shell dust is particularly hard on the lungs and should be considered toxic).
I tried tumbling these shells in my vibe tumbler, but the barrel isn't large enough to allow the shells to properly tumble. Now we have a couple of rotary tumblers with larger barrels that should be able to handle the job. Anyone got any suggestions as to what grit I should start with to accomplish this?
Chief Jim
Depoe Bay, Oregun
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Post by johnjsgems on Nov 24, 2009 7:54:17 GMT -5
The commercial guys use some kind of acid to remove the outer gunk.
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rockhead2u
off to a rocking start
Enjoying God's blessings today while living with Jesus in hope of tomorrow.
Member since May 2009
Posts: 10
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Post by rockhead2u on Nov 25, 2009 3:08:48 GMT -5
I use a trim saw to cut my abalone shell in the size and shape I want and then put them into the tumbler with 220 grit. they will need to go all the way through the pre polish and the polish to get the best shine.
I use the 220 grit and extra long time then go to the prepolish a long time and then the polish a long time.
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Post by connrock on Nov 26, 2009 5:35:52 GMT -5
I would think that tumbling will not only remove the rougher material you want to get rid of but also get rid of a lot of the part you don't want to get get rid of. john mentioned acid.It may be muriatic acid that's used but I don't really know. I do know that this acid is used for cleaning many minerals and have used it for that purpose myself. I should warn you that it is VERY corrosive and the utmost of safety precautions MUST be used. If you use a wet grinder it will eliminate the dust. I took the following from this web site: www.sazoo.co.uk/articles/jewellery/new_zealand_paua_shell.phpNew Zealand Paua Shell
Learn More about Paua
Haliotis Shells
We have a small group of shells collectively known as paua, unique only to New Zealand. The group comes from the worldwide family Haliotidae, which contains nearly 130 species from oceans in both tropical and temperate zones. These shellfish have been used for food since ancient times and have figured largely in the diet of coastal Maori. Most countries have their own local names, Abalone (North America), Ormer (Guernsey), Mutton Fish (Australia and early NZ) and Awabi (Japan) being some of the best known.
Paua is the most colourful shell in the world, other abalone have some colour, but not the brilliance of Paua.
There are three types of Paua:
Paua - Haliotis Iris
The largest, commonest and best known of our species. The shellfish is black and the interior of the shell has cloudy waves of rainbow colours with blues and green being dominant. The shells were used by the Maori to add a gleam of life to the eyes in their carved figures. Today we process them into attractive jewellery and gifts.
Silver Paua - Haliotis Australis
A smaller species readily distinguished by the silvery lustre of the inside, the cross ridging of the outside and by the yellowish colour of the animal when found alive. It lives in the same localities as the large paua but is not so common.
Virgin Paua - Haliotis virginea
A much smaller and rarer shell, this paua occurs as two subspecies, one from the southern areas and one from the north. Both are most attractive and strongly coloured shells. The shellfish is a dirty whitish colour and is not often seen alive.
Paua are marine monovalve molluscs that eat seaweed and live clinging to rocks at depths of 1 - 10 metres. They can be found around most of the NZ rocky shoreline. However, the larger and finer specimens, are found in the cold waters around Stewart Island and Southland. This is
where we get the shells used in the making of our jewellery as their colour is more vibrant.
The holes in the shell are for breathing and reproduction. Starfish are the Paua's most formidable predator as they have learnt to suffocate the Paua by putting their tentacles over the breathing holes thus forcing the paua to let go of the rock.
Environmentally sound and sustainable management practices of the paua fisheries are in place in New Zealand. There is a quota system, which is strictly enforced for the gathering of paua by both commercial and individual fishermen. No compressed air diving is allowed in the filling of these quotas. All paua gathered must be at least 125mm (5 inches) in size. There are stiff penalties for those caught removing undersize shells.
Cleaning Paua Shells
Only some paua shells can have the lime taken off without damaging the shell. Some will be too thin and brittle and will crack once cleaning starts.
We have been asked on numerous occasions about cleaning shell using acid. Please note that we do not and will not ever use acid to clean our shells. We advise that you do not try this method.
In our factory we use diamond wheels to grind the lime off. If you do not have access to a diamond wheel grinder then we advise a coarse grade of sand paper around 150 grit through to fine sandpaper of about 600 grit. Use a wet and dry paper with plenty of water this will help avoid any dust. This will leave a semi gloss finish. If a high gloss is preferred we recommend the use of a buffing wheel with some form of rouge, this can be bought from a hardware store.
This whole process may take an hour or two for each shell and it will require plenty of elbow grease.
David Finlay is the co-founder of www.silverfernz.com an online shopping site delivering the best crafts and gifts from New Zealand.connrock |
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chiefjim
off to a rocking start
Member since November 2009
Posts: 12
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Post by chiefjim on Nov 30, 2009 23:56:43 GMT -5
I would think that tumbling will not only remove the rougher material you want to get rid of but also get rid of a lot of the part you don't want to get get rid of. john mentioned acid.It may be muriatic acid that's used but I don't really know. I do know that this acid is used for cleaning many minerals and have used it for that purpose myself. I should warn you that it is VERY corrosive and the utmost of safety precautions MUST be used. If you use a wet grinder it will eliminate the dust. I took the following from this web site: www.sazoo.co.uk/articles/jewellery/new_zealand_paua_shell.phpNew Zealand Paua Shell
Learn More about Paua
Haliotis Shells
We have a small group of shells collectively known as paua, unique only to New Zealand. The group comes from the worldwide family Haliotidae, which contains nearly 130 species from oceans in both tropical and temperate zones. These shellfish have been used for food since ancient times and have figured largely in the diet of coastal Maori. Most countries have their own local names, Abalone (North America), Ormer (Guernsey), Mutton Fish (Australia and early NZ) and Awabi (Japan) being some of the best known.
Paua is the most colourful shell in the world, other abalone have some colour, but not the brilliance of Paua.
There are three types of Paua:
Paua - Haliotis Iris
The largest, commonest and best known of our species. The shellfish is black and the interior of the shell has cloudy waves of rainbow colours with blues and green being dominant. The shells were used by the Maori to add a gleam of life to the eyes in their carved figures. Today we process them into attractive jewellery and gifts.
Silver Paua - Haliotis Australis
A smaller species readily distinguished by the silvery lustre of the inside, the cross ridging of the outside and by the yellowish colour of the animal when found alive. It lives in the same localities as the large paua but is not so common.
Virgin Paua - Haliotis virginea
A much smaller and rarer shell, this paua occurs as two subspecies, one from the southern areas and one from the north. Both are most attractive and strongly coloured shells. The shellfish is a dirty whitish colour and is not often seen alive.
Paua are marine monovalve molluscs that eat seaweed and live clinging to rocks at depths of 1 - 10 metres. They can be found around most of the NZ rocky shoreline. However, the larger and finer specimens, are found in the cold waters around Stewart Island and Southland. This is
where we get the shells used in the making of our jewellery as their colour is more vibrant.
The holes in the shell are for breathing and reproduction. Starfish are the Paua's most formidable predator as they have learnt to suffocate the Paua by putting their tentacles over the breathing holes thus forcing the paua to let go of the rock.
Environmentally sound and sustainable management practices of the paua fisheries are in place in New Zealand. There is a quota system, which is strictly enforced for the gathering of paua by both commercial and individual fishermen. No compressed air diving is allowed in the filling of these quotas. All paua gathered must be at least 125mm (5 inches) in size. There are stiff penalties for those caught removing undersize shells.
Cleaning Paua Shells
Only some paua shells can have the lime taken off without damaging the shell. Some will be too thin and brittle and will crack once cleaning starts.
We have been asked on numerous occasions about cleaning shell using acid. Please note that we do not and will not ever use acid to clean our shells. We advise that you do not try this method.
In our factory we use diamond wheels to grind the lime off. If you do not have access to a diamond wheel grinder then we advise a coarse grade of sand paper around 150 grit through to fine sandpaper of about 600 grit. Use a wet and dry paper with plenty of water this will help avoid any dust. This will leave a semi gloss finish. If a high gloss is preferred we recommend the use of a buffing wheel with some form of rouge, this can be bought from a hardware store.
This whole process may take an hour or two for each shell and it will require plenty of elbow grease.
David Finlay is the co-founder of www.silverfernz.com an online shopping site delivering the best crafts and gifts from New Zealand.connrock Thanks for the hints and the time it took to look up the additional info. We did get a jug of muriatic acid when we bought the equipment, and another bottle that only has a corrosive label on it. Have no idea what that might be, but I don't think I'll be sticking my finger in it for a taste test! I'm not certain that I'm very interested in either one of the options--acid or grinding. We could grind the shell on the wet grinder, but my concern is getting rid of all of the sludge afterward to avoid any abalone dust floating around the shop once this stuff dries out. Maybe a summer project when we can move the grinder outside. Thanks for all of your inputs. Chief Jim Depoe Bay, Orygun |
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