Go to this web site.
How to Reduce the Risks of Aluminum Wiring - at The Aluminum Wiring Information Website - How to Identify and Repair Aluminum Wiring in Buildings, COPALUM connectors, Aluminum Wire connectors,Aluminum Wire Pigtailing Repairs, COPALUM Certified Electr All you ever wanted to know about hazards of aluminium wiring and tested repair methods.
I pigtailed all the all the aluminium wire in the 110 AC circuits with copper and most of the 12 v circuits as well, (especially the light and fan circuit where higher amperages might be present) in my 67
Caravel using the 3M ScotchLock method described on the site reference above. . The method requires the use of 3M Scotchlock wire nuts and Penetrox A brand Anti-oxidant. The steps are strip end of aluminum wire and copper pigtail to expose clean wire, sand with emory cloth to be sure all oxidation is removed from aluminum wire, coat both wires with Penetrox A, Twist wires together in a clockwise direction, fill 3M scotch lock wire nut of appropriate size with Penetrox A (Penetrox A comes in a container kind of like the plastic bottle that liquid glue like Elmer's or Gorilla comes with a plastic tip and little cap and consequently filling the wire nut is relatively easy), screw the wire nut onto the twisted wire and your done.
The process was not difficult, but it was tedious. Penetrox A is messy and twisting the end of the wire together isn't as straight forward as on might think. Copper wire of the same ampacity of the aluminium wire is a small guage. The aluminum wire in the
Caravel was 10 gage which works for a 20 amp circuit. The copper pigtail wire I uses was 12 gage (smaller diameter), which, because it is copper is likewise suitable for a 20 amp circuit.
It appears after checking the web site I referenced above, that there is a new method for pigtailing the aluminum with copper based on a new product introducted in July of 2007. You might want to consider that option. Good luck with your project. I suggest you put on some music you can hum or whistle along to while to you to work, it helped me get through my pigtailing project.