Buzz, we've discussed this before.
If (I say if) there was a gold gilted one, perhaps it would have been from Pharoah's royal chariot.
Before we even get to that hypothetical situation you need to demonstrate that gold has a remarkable anti-foulant property that is unknown in this day and age.
We know that copper, tin and nickel are not sufficient to provide such a level of antifoulant protection for objects in marine environments, and there is absolutely no indication that gold is any different.
First a little history on the effects
Teredo Worms and the like:
quote:
Shipworms are not worms at all, but rather a group of unusual saltwater clams with very small shells, notorious for boring into (and eventually destroying) wooden structures that are immersed in sea water, such as piers, docks and wooden ships. Sometimes called "termites of the sea", they are marine bivalve molluscs (Eulamellibranchiata) in the family Teredinidae, also often known as Teredo Worms.
Shipworms greatly damage wooden hulls and marine piling, and have been the subject of much study to find methods to avoid their attacks. Copper sheathing was used on wooden ships during the Age of Exploration, as a method of preventing damage by "teredo worms". Christopher Columbus's ships were among the earliest known to employ this defence.[1]
In the Netherlands the shipworm caused a crisis in the 18th century by attacking the timber that faced the sea dykes. After that the dykes had to be faced with stones. A genus of shipworm, Teredo, has recently caused several minor collapses along the Hudson River waterfront in Hoboken, New Jersey, due to damage of underwater pilings.[2]
These organisms cause substantial damage in only a few years to any wood structure, and would have completely consumed any wood structure not buried in mud or silt in much less than ~2000 years. This is why only buried wooden structures of shipwrecks are found.
When we look at the history of
copper hull plating to reduce the effects of marine growth and damage to vessels in normal salt water environments, we see that there were several problems involved:
quote:
Copper sheathing was the practice of protecting the under-water hull of a ship or boat through the use of copper plates affixed to the outside of the hull. It was pioneered and developed by the Royal Navy during the 18th century.
Deterioration of the hull of a wooden ship was a significant problem during the Age of Sail. Several methods were developed for protecting it from attack by shipworm and the various marine weeds - all of which had some adverse effect on the ship, be it structurally, in the case of the worm, or speed and handling in the case of the weeds. The most common methods of dealing with these problems were through the use of wood sheathing, occasionally lead. Wood sheathing effectively provided a non-structural skin to the hull for the worm to attack, and could be easily replaced in dry dock at regular intervals. It did nothing to reduce the weed growths, however. Lead sheathing, whilst more effective than wood in its stated purpose, reacted badly with the iron bolts of the ships causing sometimes severe damage.
... Britain was now expected to face her three greatest rivals, and coppering allowed the navy to keep at sea for much longer periods of time without the need for cleaning and repairs to the underwater hull, making it a very attractive, if expensive, proposition. ...
Finally a suitable alloy for the hull bolts was found, that of copper and zinc. At great cost, the Admiralty decided in 1786 to go ahead with the re-bolting of every ship in the navy, thus finally eliminating the bolt corrosion problem. This process lasted several years, after which no significant changes to the coppering system were required, and copper plating remained the standard method of protecting a ship's underwater hull until the advent of modern anti-fouling paint.
Even with the copper plates, the need to clean and scrape the bottoms was not eliminated, just that it took a little longer for the growth to reach the same level as occurs on hulls without plating. The same is true for anti-fouling paints used today and their development.
Please
do not confuse galvanic corrosion susceptibility with anti-fouling effects - all the anodic index indicates is the relative likelihood that the metal in question will dissolve when in connection with other metal objects. Gold, silver, nickle, brasses, bronzes and tin are at the low end of the anodic index, iron and steels are in the middle, while aluminum, magnesium and zinc are at the top end (and hence are used for anodes to protect steel from galvanic corrosion and why you shouldn't leave a copper penny in the bilge of an aluminum vessel). What galvanic corrosion ensures is that if there were any other metals involved that they would have dissolved when in contact with gold in any form in seawater. This is why the Royal Navy had problems with fastening the copper plates to the hulls - it resulted in the galvanic corrosion of the hull bolts and subsequent structural failure. Gold is the most active anode, ensuring that every other metal in contact with it would corrode over time.
This rules out metal wheels covered in gold plate.
When we look at the development of
anti fouling paints we see that heavy metals have been used:
quote:
Anti-fouling paint or bottom paint is a specialized covering applied to the hull of a boat, designed to slow the growth of organisms that would attach to the hull and affect performance and durability. Other types of coatings can act as a barrier against corrosion on metal hulls, or improve water flow past the hull of a high-performance racing yacht.
In the days of the clipper ships, sailing vessels suffered severely from the growth of barnacles and weed on the hull which, left unchecked, reduced the maximum speed of the ship and also its ability to sail upwind -- both of which affected profitability. Thin copper sheets were nailed onto the hull in an attempt to prevent this. A visible example of this may be seen on the clipper Cutty Sark preserved as a museum ship in dry-dock at Greenwich in England.
In modern times, paints are formulated with toxic copper, organotin compounds or other special chemistry which impede growth of barnacles, algae, and other such organisms. Since such a barrier ablates slowly, it must be renewed periodically.
Gold, gold particles and gold compounds are not, and have not been, used. When it comes to toxicity, we know that contact with gold jewelery is not particularly toxic, even when kept in close contact with human skin for many years on end (wedding rings), even though the gold there is usually in a compound with other metals, but that when combined with nickel (some "white gold" compounds) that toxic effects due to the nickel content can be noticed.
This rules out wooden wheels covered in gold plate preventing the consumption of wood by marine organisms (see
Teredo Worms above).
Marine growth like coral, barnacles and the like, can attach to any smooth surface as they excrete compounds that glue the shells etc to the surface while they feed on the passing sea water. Without a highly toxic surface, growth occurs, even on copper and nickel surfaces, which are much more toxic than gold.
This rules out the complete absence of marine growth on the surfaces of wheels.
If (I say if) there was a gold gilted one, perhaps it would have been from Pharoah's royal chariot.
When we look at the process of
gilding, there is even less likelihood of the surface surviving intact in their original geometry:
Gilding - Wikipedia
quote:
"Overlaying" or folding or hammering on gold foil or gold leaf is the simplest and most ancient method, and is mentioned in Homer's Odyssey (Bk vi, 232)[2], and the Old Testament. The Ram in a Thicket of about 2600-2400 BC from Ur uses this technique on wood, with a thin layer of bitumen underneath to help adhesion.
The next advances involved two simple processes. The first involves gold leaf, which is gold that is hammered or cut into very thin sheets. Gold leaf is often thinner than standard paper today, and when held to the light is semi-transparent; in ancient times it was typically about 10 times thicker than today, and perhaps half that in the Middle Ages. The object being gilded was coated with adhesive, usually gesso. "Gesso" is a tacky substance made of finely ground gypsum or chalk mixed with glue. Once the coating of gesso had been applied, the gold leaf was layered on and left to dry. A second gilding process was using the gold as pigment in paint. The artist ground the gold into a fine powder and mixed it with a bindery. Then the gold was applied as with any paint. Sometimes, after either gold-leafing or gold-painting, the artist would heat the piece enough to melt the gold slightly, ensuring an even coat. These techniques remained the only alternative for materials like wood, leather, and the vellum pages of illuminated manuscripts.
If all you are left with, is a thin layer of gilt paint or gold leaf, there is no structure to maintain shape, even against mild daily tidal currents. Wood or steel substrates would have corroded or been consumed with nothing to protect them from the elements and the organisms.
In a nutshell, bright gleaming gold covered intact appearing wheels lying on the sea bottom without any marine growth are highly extremely
UNlikely to survive 100 years, to say nothing of over 2000 years, without a miracle to subvert natural processes.
On the other hand, bright gleaming gold covered intact appearing wheels lying on the sea bottom without any marine growth are highly extremely likely to be part of a scam, a hoax, a fraud, hoping to delude gullible people.
Enjoy.
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