Help?

[MillerWeld]

I am new to welding. And I am taking welding classes and being I just started this class and the class I am in is just for the basics and learning how to lay down a bead, strike an arc etc. I'd like to know a few things.

1. how do you know the proper amps+volts to use for a specific metal thickness? Aside from the chart you get on some welding machines? Is it just experience, after awhile it just sticks with you?

2. how do you know how much heat a piece of material can take before it starts to distort? again, also experience after awhile?

I have welded a little before I started these classes. I just have to take the very beginner classes to get to the more advanced stuff. That's why I am asking.. Thanks for the help

[WillieB]

How much amps; There is a lot of wiggle room, but 1 amp per .001" of thickness. I say wiggle because 250 amps is way too much for steel 1/4", but about too little for 1/4" aluminum. Stick rods will give a heat range on the box, MIG you set voltage by the chart in the machine. Tig you use a pedal to get it fine tuned.

Distortion; A warm fart is enough to distort some pieces. Creating a single piece of metal from two requires metal be molten. molten metal solidifies, then shrinks as it cools. Imagine sewing elastic into a flat table cloth. It won't lay flat any more. If you can, stretch the heat affected metal to make it lay down.