Buying Surplus Aluminum Tubing?

[Kelvin]

I'm getting ready to buy some surplus aluminum round tubing from a new and surplus metal dealer. I plan to use the material to practice welding up joints.

My question is, does anyone know of any way to identify and cull out any alloys of aluminum that won't be weldable, or that won't give good results with welding? I know there are a million alloys out there.

Also, if and when I get good at this kind of welding, does anyone know what alloys are commonly used –*and if any particular alloys are preferred over others – to weld up t-tops, tuna towers and that sort of thing on boats?

Thanks for any help.

[propanehotrod]

Weld 2 peices togather then bend them. If its 7075 it will be very brittle and break easilly. Most of the surplus we see around here is 6061 which is a great all alround alloy. If its a lower grade it will still weld but wont be as strong structurally. If you are just practicing laying beads just about anything will work.

[Brent878]

My metal place is all 6061 that I know of. I found this on google with a general guide to what allows to not weld and which ones to weld.

http://www.thefabricator.com/article...luminum-alloys

[AluminumWelder]

the supplier I use eastern metal is almost all 6061 and 6063. I'd just grab a sample piece and see if it works and then if it did buy it.

Where I live new aluminum extrusion price is around $2 per pound. The local scrap metal place will sell me used aluminum for $1 per pound and if I want to sell my scraps to the local scrap metal yard I get about 40 to 50 cents a pound.

My guess is you might go through 20-30 pounds of practice metal which shouldn't cost you much more than $20 to $30 in scraps.

[polarred21]

Palmettotrooper on the THT forum may be of some help here. I have asked him a few questions myself similar to yours and he has led me in the right direction. Here is a long thread with a lot of pics of his work:
http://www.thehulltruth.com/fishing-...forms-too.html

[Kelvin]

Thanks for the help, guys.