Repairing Aluminum Castings

by Jack
(Culver City, CA, USA)

I'd love to read/hear/see your take on repairing aluminum castings, such as motorcycle engine or transmission cases. I have a set of old Harley Davidson Sportster engine cases that were pretty beat up and had quite a few cracks in them when I bought them, and have done pretty well welding them up (Miller Dynasty 200DX), but would like to get inside your brain on something like this.

As an aside, I love the site, and always look forward to your updates. I'm a machinist and a welder by trade, and I certainly believe that you never truly stop learning. Thanks!!



I will put this on the list of videos to shoot.

my short overview of welding aluminum castings is this...

**yes it can be done...its done all the time

**sometimes, the oil is soaked in really bad to where it becomes a deal where you route out the crack, clean, weld a little and get lots of black crap, route out weld and clean, weld some more a see same, route out weld and clean, weld some more and see same...etc...etc.....

until finally, it starts to weld clean.

**a 70 dollar heat gun from Northern Tool or some temp crayons help a lot in preheat control.

**getting the part to about 250 f before welding helps. but you dont want to go crazy with preheat.

**sometimes 4047 aluminum rod helps with less porosity. it has 12 percent silicon and melts at slightly lower temp so it wets out a bit easier.

**a course carbide burr that wont load up with aluminum on a small 90 air grinder is very useful

thanks for the post,


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