Aluminium Boat Construction

[quicksail]

I have a question for all the boatbuilders out there. If I am building a small aluminium boat what type of aluminium should I use? The boat is 32 ft long and will be used in salt and fresh water. I have heard that any alloy in the 5000 or 6000 range is good but I am looking for something a little more specific. This is my first alloy boat and I have only limit knowledge about it. Any info or advice would be greatly appreciated.

Thanks,

[MarkC]

www.metalboatsociety.com

Have quarterly mags and a discussion site - you need to log-on to get a password.

great site.

[sorenfdk]

Short answer:

Get Dave Gerr's "The Elements of Boat Strength"

[Eric Sponberg]

Typically, plating is usually 5083-H111 or H32 or 5086-H-111, H116, or H32. Structural members can be the same alloy, but extrusions are hard to find, therefore, a lot of people use 6061-T6 for the frames and stiffeners.

The navy uses a lot of 5456-H111, but this is more expensive.

A new alloy is out now called 5383-H116. It is higher strenth than the others, about 30% stronger on ultimate strength, and 58% stronger on yield strength, than 5083-H116, but it is also more expensive.

Hope that helps.

Eric