[atvsrfun@comcast.net]

i have watched welding videos that frown on using and welding unknown aluminum or un weldable aluminum. if it is unweldable will the weld crack. i have been practicing tig welding on some unknown aluminum and seem to be getting ok beads and penetration. i have built a prop stand with no problems yet. i can hang on it with no signs of failure. any ideas, comments?

[Coldman]

Welcome to the forum. Don't forget to go to the members Introduction section and introduce yourself and tell us a bit about yourself and what you do.

Unweldable grades are used for specific purpose by manufacturers seeking their properties, such as ladders which are of riveted construction and "scraps" as it were are not easy to come by.

Usually scraps lying around in fab shops, jobber shops and recycle yards are pretty much all weldable grades unless you see rivets or rivet holes. Not always but mostly so I would say what you have is weldable even if you don't know what grade. So for personal low risk use it should be OK.

You can still weld unweldable grades but they will definitely crack soon after welding if not straight away.