Hot Pass Pipe Welding Techniques

Last Updated/Verified: Feb 29, 2024

How to Do a How Pass on Pipe in the 6G Position Using a E7018 Electrode

This is a countiation of the previous page on open root welds and now we are moving on to how to do a hot pass in the 6G position.

Hot Pass Weld on Pipe
Hot Pass Weld on Pipe

What is a Hot Pass Used For?

The hot pass is defined as the 2nd to 3rd pass on the pipe that is done to cover the root weld. If done right the hot pass will turn a flat root penetration surface to a convex one. If your root weld does not have enough penetration or even some suck back a good hot pass can fix that!

The way a hot pass gives the root better penetration comes from welding hot and making sure the toe of the weld heat up the outsides of the pipe bevel. When the pipe cools and shrinks the root is forced to protrude on the inside of the pipe and become convex.

Hot Pass Welding Technique and Rod Angles

My hot pass or filler pass was done using a weave with a 3/32 E7018 electrode. The technique I used was to hold the sides until the toe of the weld washed into the bevel. The upper part of the bevel was held about 2 seconds and the bottom was held for about 1 second. This is the easiest part of the welding certification.

6G Pipe Welding Hot Pass Lower Electrode Angle E7018
This is my rod angle when doing the hot pass. I would hold this side and then move to the other side after about a second.
6G Pipe Welding Hot Pass Upper Electrode Angle E7018
Here is the angle I used when I got to the other side of the weld joint. The angle is same all around the pipe no matter what position. Just point the rod to the center of the pipe in the flat, horizontal, vertical and overhead positions.

How to Do a Hot Pass In The 6G Position

Before putting in the hot pass I grinded down the roots surface. When it comes to welding certifications some inspectors do not allow grinding at all but with the E6010 root they almost always allow to grind down the root. Most of the time everyone piggy backs there tacks, so you will have a few lumps on the outside of the root from the restarts. When it comes to grinding down the roots surface on critical joints it is always allowed.

6G E6010 Open Root Weld Surface Grinded Bottom View
I ground done the E6010 root pass to make sure no slag was on the surface.
6G E6010 Open Root Weld Surface Grinded Side View
Here is a side view of the ground down root pass.
6G E6010_Open_Root_Weld_Surface_Grinded_Top_View
Top view of the ground down root and this will be the base for the hot pass.

Here is are the pictures of my hot pass. I used a weaving technique for my weld holding the sides just like the above pictures of the electrode angles. As you can see the bevel is mostly filled and there is no slag on the edges of the bevel. When putting in a filer pass the slag should come off pretty easily! If not, that means you are not holding the sides long enough and there is a possibility of slag inclusions.

6G Pipe Welding Schedule 40 E7018 Hot Pass Schedule 40 Top View
Hot pass fill on the top of the pipe.
6G Pipe Welding Schedule 40 E7018 Hot Pass Left Side View
Side view of the hot pass where I ran vertical up.
6G Pipe Welding Schedule 40 E7018 Hot Pass Right Side View
The right side of the pipe and the hot pass is done.

Next page: Pipe Welding Techniques for The Cap

Contents overview of the 6G pipe welding certification:

  1. Test Coupon Preparation and Welding Machine Setup
  2. Open Root Pipe Welding Techniques
  3. Hot Pass Pipe Welding Technique
  4. Pipe Welding Techniques for The Cap
  5. Test Coupon Preparation for a Bend Test