Haven't been by in a while. Been busy getting ready for a six month volunteer stint.
We know by sooting aluminum and torching it the soot will burn to indicate the annealed condition has been reached. I doubt this is more than a coincidence as I read the aluminum oxide layer become mobilized and can be removed by rub soldering at some temperature, so I speculate annealing happens to happen at near the same temperature. That is, buring off the soot doesn't anneal the aluminum, it's the heat that anneals the work.
Is this an effective method of preparing aluminum for soldering? Does the soot act as a powerful reducing agent, turning the Al2O3 into reduced Al at the surface? Can presooting aluminum, torching it to remove the soot, and applying flux with the tip of a solder wire, then rubbing with solder wire be a way of tinning aluminum for soldering?
Inquiring minds want to know. So do I. :)
I have the equipment, solder, and flux, but not a single scrap of aluminum other than a beverage can.
I'll be working with 0.080 inch thick aluminum soon.
Doug Goncz ( ftp://users.aol.com/DGoncz/ ) Student member SAE for one year. Loves in my life: Dona, Jeff, Kim, Mom, Neelix, Tasha, and Teri, alphabetically. So that is who I spend my time with.