Undercut

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How can you prefent undercut on a 6g restricted test? I took my fist test this weekend.
Reply:Wow.  So much information.  Tell us about your settings and some more info.  Maybe we can help you then.
Reply:Undercutting can be caused by several things,here are a few. To hot, to fast travel speed, and also improper rod angle to name a few.
Reply:A simple explanation for undercut is this.   You don't fill back in what the arc just dug out.  There are many reasons why that might not take place but pretty often (more than not I would think) that is why. lol  A more wider and/or deeper penetration area than fill.Good luck manLaterLast edited by slowhand; 07-18-2011 at 08:27 PM.
Reply:I appreciate the tips! Got any more just throw them my way!
Reply:You need to say where the undercut is.  On the root, cap, where?  But again, undercut is usually where you dug out metal and didn't replace it with weld.  That can be caused by many variables.  Rod angle, heat, technique, etc, etc.Where is it?
Reply:Its mainly on the lasy stringer on the 6g position. But i really appreciate the response. I've been praticing the last couple of weeks on my angle and speed. Now i'm just looking for a opportunity to get a job.
Reply:Taking a guess on what you meant I'll assume its rod angle related.Some believe that by pointing the rod upwards while welding around the horizontal will help keep the weld from sagging downwards but if you think about what the arc is doing then many times that rod angle can make the weld sag and undercut.By pointing the rod upwards in an attempt to counteract sag we're directing more of the heat and the dig of the rod mostly onto the upper section of the weld area - which in turn heats that area up more and digs it out deeper.  By the upper area being hotter and dug deeper can make it more difficult to get the necessary amount of weld metal up there and the weld in general to stay up there without sagging off towards the lower half.  Directing the additional heat alone can make it more difficult to counteract sag let alone trying to fill in the added dug out penetration.Try a more perpendicular to the direction of weld rod angle and see if that helps (without pointing the rod up or down - ie more straight with the pipe).  The dig (the penetration) should  be more equal across the weld bead and this should help keep the heat of the pipe more equal also which should make it easier to control the sag.You may still need to control the undercut but remember that usually undercut is generally caused by going too slow with too much heat. (dug it out but didn't fill it back in.)   Good luck man