January 15, 2008
I've been using my welding equipment to weld aluminum with 4043 filler for a long time without problems. Now that I have a project that requires me to use 5356 filler, I'm having problems with fine shavings that come off of this particular wire. Eventually they clog the torch liner so that the wire won't feed. Can you tell me why the 5356 behaves so differently than the 4043?
This actually is a common problem, and it is one that I come across four or five times each year. It is caused by the fact that the 5356 wire is much stiffer than the 4043 wire. The 4043, being softer, is actually straightened as it goes through the feeder and gun. Most of the cast is removed. The relatively straight wire feeds smoothly through the system. The 5356 wire, being stiffer, keeps almost all its cast and is fed through the feeder and torch as a curved wire. The problem is that the curved 5356 is finding a sharp edge somewhere in the system and is being shaved by it.
How do you solve this? Ideally, you find the sharp edge and fix it. It can be on the feed rollers, the inlet or outlet guide bushings, at the liner ends, at the lead-in to the contact tip, or at various other places. Sometimes it is readily apparent; at other times, it can be very difficult to find.
The problem also can be caused by 5356 that has a small cast. If you measure the cast (Aluminum Workshop,"Defining cast and helix," Jan./Feb. 2004, p. 42) and it is less than about 14 inches, this may be the problem. In this case, you may be able to use a wire straightener to remove some of the cast.
Alternatively, try a different spool of wire or a different manufacturer's wire. Cast can vary appreciably between spools and suppliers.