4 ms·
> Hull Cladding Interesting, but after giving it some thought (I actively research steel hull efficiency), doubtful. It's true that gold is highly stable in se
by mojomark 7y ago
> Hull Cladding
Interesting, but after giving it some thought (I actively research steel hull efficiency), doubtful. It's true that gold is highly stable in seawater when not in contact with other metals, however, put it in contact with steal and you have a fairly decent dissimilar metal reaction leading to galvanic corrosion of the hull over time. (1) Gold is very soft, so any impact with common marine debris (logs, scrap, buoys, etc.) may very will penetrate to the steel hull structure, which unless quickly repaired would lead to the above corrosion. In general, hulls are designed to account for 40-50yrs of service life corrosion before needing to be scrapped.
However, this comment made me ask the question of whether or not gold is a good antifouling agent to prevent marine growth. After all, we've all seen shiny non-fouled gold being pulled from ancient ship wrecks. I really can't find much data on gold preventing marine growth, but if successful, cost-effective, and non-toxic (as copper is), that would be a major savings in terms of fuel efficiency for ocean-going vessels.
1. https://blog.samtec.com/post/dissimilar-metals-in-mating-connectors https://blog.samtec.com/post/dissimilar-metals-in-mating-con...
- LifeLiverTransp 7y agoWhat if it is only applied one atom thick- as in plated on with a galvanic bath?
- logfromblammo 7y agoI actually thought the steel skin would be covered with in insulator layer, such as paper, fiberglass composite, or plastic sheeting, and the gold bonded to that. Punctures and crushed panels would then be detected by changes in capacitance. And now I'm imagining arcs from improperly grounded inner hulls, so maybe that's not the greatest idea for gold. But if gold resists the barnacle adhesive even a little bit, that's already a major win.
- btilly 7y agoAs a consumer I can buy gold leaf for around $10 per square meter. Estimates that I have seen are that the big cargo ships are around 400 meters long and 50 meters deep. I'm not sure their surface area, but let's call it 60,000 square meters. (22,0000 for each side of a wall of those dimensions, and some amount for the bottom. So to gold plate it is a half-million dollars. https://www.quora.com/How-much-does-it-cost-to-fuel-a-cargo-ship https://www.quora.com/How-much-does-it-cost-to-fuel-a-cargo-... estimates $130,000 per day for a ship under power. If gold plating worked, lasted, and didn't leave damage, someone would have figured out that it was worthwhile to do already. So if you deal with it professionally, by all means look into it. But I wouldn't be too hopeful.
- DuskStar 7y agoI can't wait for some billionaire to do this with their megayacht. Who cares if it's not cost efficient!
- heavenlyblue 7y ago>> As a consumer I can buy gold leaf for around $10 per square meter. That leaf is probably an order of magnitude (if not two) thinner than your kitchen foil.
- btilly 7y agoYes. In fact gold leaf is 0.1 microns. Standard aluminum foil is 0.016 mm = 16 microns. So 160 times thinner, or about 2 orders of magnitude. When used to gild buildings in air, it typically lasts 40-50 years. Of course a ship's hull in water is likely to be a much more hostile environment...
- heavenlyblue 7y ago>> When used to gild buildings in air, it typically lasts 40-50 years. Of course a ship's hull in water is likely to be a much more hostile environment... But gilding is a purely ornamental technique. It's not there to defend the lower layers from elements.
- btilly 7y agoThank you for the explanation of WHY it is likely to be a much more hostile environment.