It's been a while since I've posted. Mainly because I've been busy building (and a good deal of time in the moaning chair)
My latest question is this:
What are everyone's thoughts on using aluminum for decorative features on my weekender? I will be using a lot of stainless steel bits in the rigging so I wanted to add a few "silver coloured" items elsewhere. The problem is that I'm not really set up to work with stainless steel so I wanted to know about using aluminum. I am aware that it will pit and discolour, but how fast and is there any way of protecting it. My weekender will be stored on its trailer and sailed equally in fresh and salt water.
My first project would be to use aluminum in place of the plywood ring and circle of the ship's wheel.
Thanks in advance.
Steven Goodman
Future Weekender working name "Isla" (it's gaelic)
Aluminum has some advantages and of course disadvantages in the marine environment, like most everything else. Corrosion can be staved off with regular maintenance and cleaning (plus protective coatings). The type of alloy used can affect the ability of this metal to fight the ills of life aboard. 5083, 5086, and 5456 alloys are pretty standard in the industry and offer much better corrosion resistance then other types. The type of welding also has a great effect on how well this material will hold up. MIG or better yet pulse MIG or TIG (for fine work) will be the best ways to go.
Mixing metal types in the boat can lead to difficulties (electrolyses), but this can often be overcome with clever attachment (bushings, inserts and isolators, etc.) to keep these metals from direct contact.
Aluminum properties are pretty weird when you get into the engineering of parts. I designed an aluminum ketch last year and discovered a number of interesting oddities during structure calculations. First of all, this is a flexible metal, quite so and it generally needs more panel support then other materials, like plywood or steel. Once you get the strength necessary for the task, the weight rivals wood and often the pieces are similarly sized. Given the choice (and similar strength), I'd oft for a wooden part then aluminum, just because it looks and feels better in the hand.
For the most part, aluminum can be worked with most wood cutting tools, though they'll not like it for long. An aluminum ring (ship's wheel) is an interesting idea, though you'll need to "box" it or use a substantial plate thickness to get the strength needed. Maybe an aluminum hoop around the spokes, so you can glide your hand over the wheel, rather then bounce from spoke to spoke. Tubing will do fine and offer some sparkle, if you keep it clean and polished. Capping comings or using slit sections of tubing as chafe protection seems reasonable enough. Go for it . . .
Back when I had a life, I used to mess around with blacksmithing. When I finished a piece, I'd warm it up and work in some beeswax. This coated the surface and prevented rusting but of course, it wasn't permanent and had to be reapplied on occasion. I'm going to be casting some aluminum decorative bits for my vacationeer and I'd be interested to learn what you're going to use as a protective coating-there's gotta be some high tech polymer that will out-perform beeswax! I'll also have silver and wrought iron (real wrought iron-not steel) and I'm open to suggestions.
Thanks for the info.
Yes, I do love the celtic knot wheel. I unfortunately saw it after I had cut out the parts to my wheel.
Also, just to be clear, the majority of the wheel will be wood. The only aluminum parts will be a 1" wide ring made of 1/8" plate on the front face and a circular plate on the face at the hub of the wheel. I have a relative who does great engraving work and I may see if he will engrave a thistle on the aluminum on the centre hub.
I'll try to do a little research on how to preserve the aluminum. I have never really worked with metal before so any advice would be welcomed.
Depending on how this goes, I may (or may not) add other little details to the boat.
Getting ready to flip and glass in the next couple of weeks. Wish me luck.
Steven Goodman.
Penetrol will provide a protective coating. This is the oil based paint additive (a wetting agent) that old timers have been secretly coveting for generations. It will need to be renewed a few times a year, depending on how much direct sun it receives and the care the part gets. For better protection you may be better served with a clear polyurethane applied in several thin coats. This will provide considerably more protection, it'll be harder, able to withstand mild abrasion and UV inhibitive much longer. The down side to this and many "modern" coatings is, if you let the coating go to long without maintenance, it will have to be completely removed and done again, where Penetrol type coatings can be applied, restored (buffing in fresh stuff) and maintained without it flaking off from lack of attention (it just disappears and the aluminum will begin to oxidize, if left alone).
Penetrol, excellent, thanks.
I'll post pics when I'm finished.
Steven Goodman.
![[Image: IM000455.JPG]](http://custompaperpocketyachts.k-j-g.com/images/IM000455.JPG)