Aluminum Stanchions ?

[04 Marine]

Nick,

You just made life a lot easier for me.

Glen

[Joli]

Here ya go. We have aluminum, or if your British aluminium, stanchions. They are 24 inches high, 1 inch base diameter, solid. I assume they are 6061 but could also be a 2024 alloy. They are original with the boat, 36 years old and seem to be somewhat durable.

Slowing down so we can enjoy lunch and watch a tall ship sailing nearby.

[ConradG]

Aluminum stanchions will be plenty strong enough! Mine is an aluminum Colvin Gazelle with sockets welded to the bulwarks and pipe inserted for the stantions. The lifelines are plastic coated and tread through holes drilled in the pipe. The tops are capped and the bottoms left open. Another scheme I have seen is rings of 3/16 round welded to the outside of the pipe. In any case, the same pipe and socket arangement is used with a bent piece that has a pully on the end and extends out horizontally almost three feet as an anchor davit or cathead. The anchors are 75# fishermans. I would bet that you could easily hoist that 450# guy by them!

If you have access to 5000 series aluminum for your portlights and anything else it will do much better than 6000 series in the salt environment. Especially if you don't protect it with paint. With any aluminum your biggest problem will potentially be with galvanic corrossion. If you don't want the crusty corrossion of your aluminum you will need to keep stainless from being in contact with it. Stainless is at the opposite end of the scale and everywhere there are stainless bolts, even on painted aluminum, on my boat there is the crud. They will all be replaced with hot dipped (not plated) galvinised steel. Both zinc (galvinised) and mild steel are very close to aluminum and although they can rust themselves they don't eat the aluminum through galvanic action. Loss of material on your aluminum stantion bases might not be that big a problem if you build them heavy enough but on my hull I would rather not have any stainless giving up the aluminum's electrons!!

Aside from galvanic corrossion there is poltice or crevass corossion to consider wherever oxygen is kept away from the material. (Same with stainless-ever notice the rust coming from under chainplates?). The oxygen allows the creation of a layer of protective aluminum oxide. Without it aluminum corrodes. By painting (directly after sanding to get the paint to adhere to the aluminum and not the oxide that has formed) the undersides of the bases and bedding them the best you can this can be minimized. Exposed bare aluminum is very corrossion resistant so long as it is exposed to the air but will show light white crust with time no matter what. A quick scrub with a scotchbright pad or 'green scrubby" from the supermarket makes it shine again. There are chemicals that work wonders also-witness an acid wash on my aluminum livestock trailer after 120K miles each year and it looks like new again! On small parts (I used to manufacture packframes) wire brushing seemed to do wonders for a longlasting finnish. Might of had something to do with smearing the surface of the material but they seemed to stay shiney and not crust with time.

Do you have any pics of your aluminum portights? Want to offset your costs a bit and sell a few?

[David M]

I have seen plenty of aluminum railings and aluminum stanchions on aluminum workboats. Only for yachts are they relatively rare. If you use large enough scantlings they are just as strong as stainless steel stanchions, railings and pulpits.

[s/v Jedi]

We have the paint (powder coating) flaking off our Bomar cast aluminium hatches. In 2005 I decided to do a test with a small hatch on the foredeck. I removed all the paint and polished the aluminium with 3M polish for magnesium/alloy wheels (car product). I never touched it since and it still looks exactly the same as that day in 2005. It looks good too, much better than with deteriorating paint or powder coating so we're gonna do the same for all hatches.

cheers,
Nick.

[04 Marine]

Nick,

Polished aluminum is really bright and very reflective. I rebuilt a Cessna 140 some years back and polished out the fuselage, the wings were fabric, and it looked great. I'll have to see if I can find my pictures and post some.

To All,

The suggestions received are great, thanks to all for your input and comments. I realize that aluminum is not a normal for yatchs, but it is a metal that I am comfortable with and I find it easy to shape and weld.

Glen

[s/v Jedi]

Originally Posted by 04 Marine

Polished aluminum is really bright and very reflective. I rebuilt a Cessna 140 some years back and polished out the fuselage, the wings were fabric, and it looked great. I'll have to see if I can find my pictures and post some.

I went out and took a photo of it for you ;-) It isn't bright at all after using the polish and it obviously protects it all so good that the last flake of paint won't come off ;-)

So, this was polished in 2004 and never touched since except with the deck brush.

ciao!
Nick.

[44'cruisingcat]

Originally Posted by s/v Jedi

Or you can use bronze and chrome it....

Or they can be composite:

[04 Marine]

Crusingcat,

That is a concept that I had not considered. The landing gear on my last airplane, a Longez (Rutan Canard design) was composite. My ideal touchdown speed was 75knts. It could take a beating. I this case, a traditional cutter, I'm going to stick with metal, I'm just not sure yet whether it will be aluminum or stainless steel. I am leaning towards aluminum.

Glen

[David M]

Originally Posted by s/v Jedi

We have the paint (powder coating) flaking off our Bomar cast aluminium hatches. In 2005 I decided to do a test with a small hatch on the foredeck. I removed all the paint and polished the aluminium with 3M polish for magnesium/alloy wheels (car product). I never touched it since and it still looks exactly the same as that day in 2005. It looks good too, much better than with deteriorating paint or powder coating so we're gonna do the same for all hatches.

cheers,
Nick.

Yup...I had an aluminum Markey cable winch powder coated before delivery. The powder coating started blistering within a few months. The only thing that ultimately seems to stick to aluminum is aluminum oxide.