(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,