Tuesday, July 31, 2012

A little about welding..

Some good books

  • Farm and Workshop Welding
  • How to Weld: Techniques and Tips for Beginners and Pros (Motorbooks Workshop)

Phases of not being able to weld (just stick welding mild steel - lets not get silly just yet)

  • Can't strike an ark
  • Can't run a bead
  • Can't run a neat bead
  • Bead is (too high,  too flat, undercuts the metal, laced with inclusions)
  • Can't join metal at all
  • Can break metal about with bare hands
  • Can break metal with hammer
  • Can sometimes break metal with hammer
  • *Can't make neat weld to join metal
  • Can't always make neat weld
  • Take a lot of attempts to dial in the right settings on a different type of joint.
If I get past this list, I'll consider my self to be about "beginner" status.

I guess it's true of so many things. They seem simple until you start to learn about them, and then you find out how much is involved.

Some Simple Ideas 

(Bear in mind I'm an utter novice, so this has very little authority behind it) 

Too cold, you only join the surface. Too hot you burn through.

Too Hot, Speed Up to compensate, and you don't deposit enough metal, you get undercutting.

Too Cold, Slow down to compensate, you end up with too much metal, and inclusions from the slag getting around you.

As you run a weld, the metal heats up, at the start it's stone code. Circle at start for a second before you start moving.

On thin stuff you need to do short welds, then let it cool. Repeat.

More weld material does not make a weld stronger, a nice convex fillet is stronger than a blob as the blob introduces a sudden change in thickness of metal, which is a stress point. The weld is stronger, the joint is weaker. It will break at the edge of the blob.

Buy an automatic helmet. As a beginner this makes a lot of difference.

* I'm about here, on a good day. With varying degrees of the preceding problems.