Originally Posted by nzmal
We're looking at a couple of aluminium yachts at present, both of which require flights to view so we're yet to look through them.
A couple of things that have occurred to me that someone will likely have an answer for...
1. Unpainted aluminium oxidises and is low maintenance, I get this and like the concept... but does the oxidation leave blackening on hands and feet when contacted? I had an aluminium bar attached to a shingle rake at home and when I used it my hands ended up black from the oxide...
2. Is the noise from aluminium hull significantly greater in passage or at anchor than fibreglass boats?
3. Does the lighter construction necessarily create a less sea-kindly motion in passage or are there ways to overcome-compensate this?
4. I've read varying reports on the heat generated from unpainted decks in the Pacific climate, does anyone have a frame on this that comes from experience (is it too hot to walk on all day... or how is this overcome without painting?)
Two aluminum yachts I've worked on extensively and sailed/made passages on are a custom Palmer-Johnson 52' sloop
and a custom 54' cockpit
MY. The PJ was finished like a yacht: Awlgrip'd and varnished trim; the MY was finished like a nicer work boat, but mostly unpainted outside. The PJ had extensive corrosion
issues, integral aluminum holding tank
, for one. The MY had none. As to your questions:
1--Bare aluminum oxidizes as it is exposed to weather
. Examples of this oxidation are everywhere for us to see, street light and sign poles being just an example. The surface oxidation can rub off on your hand or clothing
, if you rub hard enough. But on a yacht, regular washing
controls this to a great degree.
2--Generally, aluminum boats are very definitely noisier than wood boats; glass boats fall somewhere between them. Compare the sound made by your wooden chop sticks, against the lacquered wood bowl, with the sound of stainless flatware against an army stainless tray.
But there are many ways to partially compensate for this through thoughtful design and the use of damping and sound deadening materials.
3--In a well designed cruising boat the relatively small weight savings of aluminum construction (over composite construction) should not significantly affect its motion.
4--Metal is most unforgiving on bare feet. And decks require some type of non-skid. The crew of one famous yacht discovered they needed mountaineering boots to cope with an oh so slippery, bare aluminum diamond-plate deck. A teak
overlay can be exquisite, but it's costly and requires extra care. Sand in paint is pretty tough on exposed skin; Griptex is better. Treadmaster type coverings provide insulation
and can be more comfortable on bare feet, but stain easier and must be carefully glued down using epoxy
glue. Imitation teak
decks look, well, imitation...ugh!
As far as hot metal, aluminum makes a most excellent heat sink.