raw aluminum for chassis and general fab

[xtian]

Which alloy and what thickness?

http://www.mcmaster.com/#standard-aluminum-sheets

[Cantplay]

I prefer 6061, .090" You might get away with .060".

John

[jhaas]

have you shopped locally? I can get a 4' x 8' sheet of .060" here for just under $100.

[Jerryz1963]

I relied on the advice of experts in the field of sheet metal fabrication. Their advice was to not get a really high grade alloy because it's more brittle and liable to weaken considerably when you work it (bend it). They suggested for metal that is going to be bent and shaped to stick to the 5000-series alloys. That advice is entirely consistent with my limited metallurgy training.

The price mentioned of 100 bucks for a 4x8 sheet seems quite reasonable, and consistent with what I have found. However, I live in the largest city for hundreds of miles.

I looked online, but I think you'll find shipping is going to bring the cost up dramatically; hence, a local supplier is probably going to prove most cost-effective.

[rp]

Which alloy and what thickness?

http://www.mcmaster.com/#standard-aluminum-sheets

Nice!

[Ken Moon]

I really like the 5052-H32 alloy at a .09 thickness. It's strong as heck, yet still weldable and bendable. Its strength makes it usable for guitar chassis at the .063 thickness, when using up to 50 watt tranny sets. For big honkin' 100-watt iron, I'd stick with .090

The 6061-T6 is a popular and readily available alloy that is very bendable, but it is usually heat treated when strength is very important, and I wouldn't use it at any less than .09 thickness.

When bending sheet aluminum, it's super important to use the proper minimum bend radius, to avoid cracking along the bends.

With the 5052-H32 alloy, you should have a minimum bend radius at least equal to the thickness of the sheet, and with the 6061-T6 alloy, you have to use a radius at least twice the thickness of the sheet.

[xtian]

Thanks, Ken, and everyone!

I'm not planning to build chassis, but want to have some sheet Al on hand for small jobs, like adding an output jack to an open-backed cabinet, or for control panels, etc.

Our local metal supply place closed last year. I'll have to ask some contractors if there's any local supply.

[Milkmansound]

there's a place here in SF that keeps their scrap pieces - they let me raid the scraps for not too much money. I would try to find a metal shop and see if they can do the same for you

[billc]

Thanks, Ken, and everyone!

I'm not planning to build chassis, but want to have some sheet Al on hand for small jobs, like adding an output jack to an open-backed cabinet, or for control panels, etc.

Our local metal supply place closed last year. I'll have to ask some contractors if there's any local supply.

Ask at a local welding supply shop, they will know...many times metal is a sideline for another business, i.e. I used to buy metal from a big mill supply company in Ukiah.

[Zippy]

The 6061-T6 is a popular and readily available alloy that is very bendable, but it is usually heat treated when strength is very important, and I wouldn't use it at any less than .09 thickness.

"T-6" specifies the heat treatment - it is a precipitation-hardened alloy. Welding it will put the alloying elements back into solution, so if you weld it, the heat-affected zones will be soft. You either use it as-is or heat treat it after welding.