self learning

admin

I am trying to learn by doing. (And by asking you guys)What is the best method to hold the gun when welding 1/8" bar to a 1/16" plate?or something different than what I depict?BTW I am using a flux core welding machine set on high (90 amps) and a wire feed setting of around 6.thanks.merc
Reply:When welding thin material it can be easier to push the weld puddle rather than drag it.  This will help minimize blow through.  You will get enough penetration on that thin of material by pushing the puddle.  When welding thin materials it is also helpful to tack in several places and skip around with your welds to minimize heat build up and metal distortion.  If the weld is fairly short you can tack them and make one pass.  When welding materials of two different thicknesses it is best to keep the heat on the thicker material to ensure penetration and you can pull the puddle into the thinner material for penetration. For your example you should keep the heat on the 1/8" material and let the puddle wash into the 1/16" material this will get you penetration and help minimize blow through.  You will have to experiment with your distance, angle and speed to find what works right with your setup.
Reply:Mig and fluxcore aren't my strong point, but I don't think picture C is a good idea. Tinner has some good advice there.
Reply:It may be easier to push the weld puddle with fluxcore, but you will end up getting slag inclusions in the root of your weld.  With Fluxcore, it is best to use a slight drag angle and have the wire pointed toward the center of the joint you are welding and at the leading edge of the puddle.
Reply:I'm kind of a new student (1.5yrs) and have had several jobs involving Fluxcore, so I'll share what I've learned with you. The best option in this picture is definately B, you want to point it directly into the groove at say about 45 degrees, or even a little less to get more heat towards the top plate (I assume is the 1/8). Tinner is absolutely correct, your heat will go towards the smaller plate, so try to put it more on the 1/8. You can do both push and pull, but I prefer pull everytime, it gives you way better penetration and less chance of slag inclusions.The trick is to make sure your setting are correct, you want a nice consistent sound and feel like you're feeding enough wire into your puddle. If you feel the plate is too hot, don't be scared to stop, restarts I find are very forgiving with the Fluxcore process.To avoid undercut, you can even do a little weave on a lap joint like that.For future references, I have done it like C, but you need the right speed so you burn away the edge and penetrate the bottom plate, but I don't recommend it as your bottom plate is too thin and will take most of the heat.Hope I helped for my 1st post