Whoa! Did I accidently re-subscribe to SUB-ARCH??
Seriously, I fully support Betty's statement. I have seen too many botched
garage-lab jobs. Maybe a qualified chemist could get along okay, but for most
of us I quote one of my favorite sayings: "A little knowledge is a dangerous
thing"!
John Broadwater
"Seifert, Betty" wrote:
> Working with divers is sometimes successful, however, it is usually after
> they have destroyed something and have decided that their garage elecrolysis
> or flush method hasn't worked. Removing salts from artifacts requires a lot
> of patience. A few washes in distilled water and a short time in
> electrolysis doesn't do it. I find an iron artifact may have to go through
> a number of cycles and that you have to do testing for chlorides and keep
> going until the chlorides are reduced to <2 ppm. Stabilizing glass, brass
> and bronze requires more than is readily visible. They look good rather
> quickly, but they are not necessarily stable. Many treatments require
> analysis to determine the best treatment. I really think it is misleading
> to tell someone they can conserve their artifacts for $100 in equipment and
> supplies.
>
> Betty Seifert
> Deputy Chief
> Maryland Archaeological Conservation Laboratory
> (410) 586-8578
>
> > -----Original Message-----
> > From: [log in to unmask] [SMTP:[log in to unmask]]
> > Sent: Monday, 29 January, 2001 5:58 PM
> > To: [log in to unmask]
> > Subject: Re: Wreck Amnesty Announced
> >
> > Perhaps I should further explain what I meant by:
> >
> > <<The process for preservation of most of the items recovers by divers -
> > Brass, glass, some iron - are easy to learn and do with a little knowledge
> > and about $100 in equipment and chemicals.>>
> >
> > I have my BS in chemistry and have spent the past 16 years at a US
> > aerospace
> > manufacturer running the chemical plating and processes. So I am familiar
> > with chemical treatment processes and can understand the preservation
> > treatment of artifacts. When I said "most of the items recovers by divers
> > -
> > Brass, glass, some iron are easy to learn" I meant it. I am comfortable in
> > saying that 90% or more of all artifacts recovered by wreck/sport divers
> > come from steel wrecks built/sunk since 1890. I will also say that of
> > those
> > artifacts recovered the vast majority of them are brass, glass, or china.
> > Sport/wreck divers in the US and UK/Northern Europe just do not see 300
> > year
> > old glass bottles and iron/organic conglomerations that often. Divers
> > rarely
> > will recover iron or wood as most capable of recovering large artifacts
> > know
> > of the problems involved in preservation.
> >
> > Please go to www.Divernet.com click on wrecks and take a look at "top 100
> > wrecks", these are the type of wrecks the sport/wreck divers are doing
> > around the UK. If you go through the list you will find that of the 102
> > wrecks listed (2 listings are for sites with 2 wrecks apiece) only 3
> > predate
> > 1850. They are Association(1697)90 guns, Fra Metta Catharina Flensburg
> > (1786)Danish Brigantine, and SS Forfarshire(1838)- paddlesteamer. Of these
> > 3, both the Association and the Fra Metta Catharina Flensburg are
> > protected
> > and can only be dove with permission and the Forfarshire is well broken up
> > in the tidal zone. Of the rest of the listed wrecks 10 are sunk between
> > 1850-1898, and 89 post 1900. Sport/wreck divers just do not dive many
> > wrecks
> > where the problems of multiple materials and great age are encountered.
> >
> > Because of the relatively new and good preservation nature of the
> > brass/glass/china artifacts divers recover, they are easy to clean and
> > preserve properly. Divers just do not recover many concretions of
> > artifacts
> > from wrecks that are of archaeological interest. They also do not have to
> > work with many different substrates at the same time. The most common is
> > the
> > brass/glass combination of a porthole. However, I do agree that even
> > though
> > the process for newer brass/glass/china artifacts is easy, it is not
> > always
> > done correctly if at all. Many divers still only use HCl baths and wire
> > wheels. But they can learn.
> >
> > As to iron, the problems stated in the other posts are encountered and
> > many
> > times the preservation processes are not done or done improperly. However,
> > simple electrical baths using sodium carbonate with the DC current at .5-2
> > amps are very simple to make and control. The chemicals are cheep, sodium
> > carbonate (washing soda) is use for control of swimming pool pH and the
> > bath
> > tank can be made from plywood and construction plastic to any size and
> > shape
> > required. Stainless steel anodes can be made from cheep 316 alloy sheet.
> > The
> > power sources can be a dedicated rectifier or 12 volt battery chargers
> > with
> > a simple amp control and meter. The trick comes in knowing how to place
> > the
> > anodes and determining when the chlorides have been removed. Both of these
> > two points can be learned for simple material combinations.
> >
> > Again, divers will rarely recover and try to preserve concretions of
> > multiple materials. They generally keep to brass/glass/china.
> >
> > As for some of the other points made:
> >
> > "The real problem is not so much the technical details of conservation,
> > but
> > the recovery of information contained within the artifacts or
> > corrosion/decay."
> >
> > "Good conservation is not that easy as those who have set up these garage
> > labs have found out to their sorrow when their "treasures" end up falling
> > apart into little bits."
> >
> > "If you are cleaning objects you are liable to lose a lot of evidence
> > through lack of experience, the same as doing an excavation without any
> > training. Some conservation techniques also destroy evidence. It is this
> > knowledge and experience which would be very hard to transfer easily to a
> > diver, or indeed many archaeologists come to that."
> >
> > As I stated, divers will rarely recover concretions of multiple artifacts.
> > You just do not see much concreated to a porthole, bell, or steam gauge
> > that
> > was unbolted from a W.W.I or W.W.II wreck.
> >
> > If the archaeological community were to be more out going to the
> > wreck/sport
> > divers on the problems of preservation and loss of information for the
> > types
> > of artifacts referred to above, you just might reduce the amount of
> > recovery
> > of these objects that is occurring. I strongly support the efforts of the
> > NAS in reaching out to wreck/sport divers but I still do not see many
> > archeologists presenting at the large dive shows. I know that if you were
> > to
> > suggest doing a workshop on identification and preservation of wrecks and
> > artifacts the shows would welcome you. You might also just change some
> > attitudes and find some volunteers in the bargain.
> >
> > Pete Johnson
--
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* * * NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION * * *
John D. Broadwater, Ph.D., Manager “NOAA's National Marine
MONITOR National Marine Sanctuary Sanctuary Program: Stewards
c/o The Mariners' Museum for Future Generations.”
100 Museum Drive
Newport News, VA 23606-3759 “The MONITOR National Marine
757-599-3122 (fax 591-7353) Sanctuary: Protecting the
[log in to unmask] Remains of the USS MONITOR--
http://monitor.nos.noaa.gov a National Historic Landmark.”
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