Welding Tips and Tricks

I need some tips on welding a cast aluminum rim. I have a Miller Syncrowave 200 that I will be doing this repair with. The crack in the rim is not that big at all, I am running it at 200 amps on AC. The problem that I am having is that it is not starting a puddle very well, then when I have one my filler just gums up. I know how to weld aluminum and I know it has to be be super clean. With this being a rim, it was dirty but I have cleaned it up the best I could. I have not used acetone or anything yet because there was none in the class, I am welding this at my high school. The puddle seems to be getting contaminated too also even though I have cleaned it, any feedback would be great! Thanks!

Well even though you cleaned it, the heat is probably drawing contamination out of the crack. It also sounds like you don't have enough amperage even if the repair was clean, I would also advise that welding on a rim may not be a good idea, if it fails in service...someone could be injured or worse.

Richard,
Thank you for the advice! I did not think about the heat drawing in contamination to the puddle! The Syncrowave I have has a max of 200 amps so I don't have anything else available to me that has more amperage. Thank you for your feedback!

I agree with the safety issue however if you must repair.... You can pre heat with a torch, and make sure the rim is truly cast alum, a lot have magnesium mixed in which could also cause you issues.

Cast rims are thick and suck up a lot of heat. If you have access to another flow meter get a bottle of helium from your
gas supplier and "Y" the two hoses together. Run 50-50 argon and helium and watch how fast you get a puddle now.

Or, there's always JB Weld!

You are in high school so your teacher should be telling you this - dont weld on car/truck aluminum rims.

Without the experience and knowledge needed to do a quality repair - this is a bad item to weld.

For learning and practicing, do not do it on items that can kill people.

In my opinion.

Okay that sounds pretty reasonable! It was the automotive teachers rim that's why they wanted me to do it but I understand I probably won't mess with it anymore! Thank you guys for all of your feedback!