Canopy frame material, aluminium or stainless steel ?

[hyboats]

I am chosing canopy frame for my boat, some one said aluminium is better, it is light and lower cost, some others said stainless steel is more shining and beautiful.
confusing

[hoytedow]

Both are true. I would use aluminum.

Beauty lies in the eye of the beerholder, no doubt. But it will be easier to get it already done to fit that boat in SS, than to design and weld it in AL.

[alan white]

Stainless, because the tubing cost is but a small part of the overall cost. And stainless is hands down the better material, looking new for many years. Fasteners for either material are generally stainless, which matches the stainless tubing galvanically.

[hoytedow]

I sit corrected.

[tom28571]

In the T top, which one do you want to grab hold of to keep from going overboard? Stainless, hands down. All that gear attached to the T top will be much more secure on a stronger frame. I recently had to rebuild part of a bimini that is made with aluminum tubing. It was damaged in contact with a piling. Stainless would probably have just been bent a bit and required only straightening.

[Bglad]

All the comments about stainless are true but I can't remeber when I last saw it used on a boat like the one in the OPs original message or any other.

[mydauphin]

All above is true, but if you price the labor and materials you might find Aluminum a lot cheaper and as good if you have it anodized. You have to get someone that really knows what they are doing either way. The quality is in the workmanship. I have seem cheap ones and they look cheap, and well built ones that look like works of art, both in AL and SS.

Originally Posted by Bglad

All the comments about stainless are true but I can't remeber when I last saw it used on a boat like the one in the OPs original message or any other.

I cannot remember when I have seen anything else but SS on such application.

[mydauphin]

There seems to be a geographical difference going on... In South Florida, AL is most common in Boats under 30'.
May be you guys are confusing Anodize Aluminum for Stainless Steel. Check out http://www.atlantictowers.com/at_sub/faq.html

[yipster]

when canvas and frame should fold the accesoires and hinges are important
i see they also come in alu so can be an anodised but would the little screws still work
ss railings too is expensive stuff and i've been wondering on the subject before

[mydauphin]

The Aluminum is bent and welded as needed. Stainless steel is much harder and will give rust streaks at welds over time. Either one can crack if not done right. The guy that does welding for me and Atlantic mention link above make beautiful welds and can even make them invisible.

Originally Posted by mydauphin

There seems to be a geographical difference going on...

That might well be the case. Sometimes we tend to see the world from our armchair only.

[alan white]

Stainless is what lifeline stanchions are made from in almost every case, no matter where the boat was built.
Rust should not be a problem on any well-polished weld as long as the welding rod is correct and the pipe is correct (316 stainless, e.g.).
Simply compare to existing similar stainless parts such as the stanchions mentioned, or bow and stern pulpits.
Over time, given enough salt water exposure, any stainless will need to be repolished. Yet, it's only the surface that requires the maintainance and it isn't much work.
I've seen anodized aluminum with a few years on it (spars) and refreshing the surface back to original is impossible or at least prohibitively expensive.
It has to be painted, normally with two-part paint.

[CDK]

If you use aluminum with stainless fasteners you might as well put it together with rivets because after a few months at sea you cannot take it apart anymore.

As Alan White says in post #4, the price of stainless tubing is only a small part of the total costs.

The best polished stainless parts on my boat is the 25 years old canopy frame. The fabric and the wind caress it every day.