[miffyleslie]

I am about to begin an Aluminum project for my boat. The material will be 1 1/2" Sch.80 pipe. The three grades available at my Aluminum distributor are 6063 - 6061 - 5086. There will be no pressure in these pipes. Only structural.I am not going to make any bends. All joints will be either miter joints or coped saddles. My question is, What would be the best grade to use of the three available to me? I need strength being in a side load rather than a supporting load if I am explaining right... Help!!

[Otto Nobedder]

Welcome!

I'd choose the 5086, for the following reasons:
6063 is very malleable. It's what I choose when I have to form something that needs 6XXX properties, like bending pipe on a liquid nitrogen vaporizer. Not the best choice for structure.
6061 is a good choice for structure, but is overkill in cost when you realize your entire HAZ no longer has the properties of the metal you started with.
5086 welded with 5356 will end as nearly what you started with, economically.

I'm also in Louisiana, working in Slidell. Where are you located?

Steve S

[miffyleslie]

I am in the Houma area. The framework I am building is actually going on my boat to do some shrimping. "Skimmer frames" if you've heard of that before. I've welded lots of Aluminum before but never knew the properties of the material being welded. I was always told, "Here.... weld this and use these rods". So here I am today.....