How to Prepare a Butt Joint

If you add a piece of metal to the body of a car, or simply put 2 flat pieces of metal together by butting the edges up end to end, you create a butt joint. The thicker the metal, the more important it is to take additional measures. You need to prepare the metal first to weld a strong butt joint.

Difficulty: Moderate

Instructions

Things You'll Need:

• 2 pieces of metal
• Friction clamps
• Welding table or similar surface
• Angle grinder

1. Clamp one side down to a solid area. Leave the edge of the metal extended beyond the table, so that you have easy access. Make certain both sides are firmly in place. A simple friction clamp is adequate for this job.

2. Use an angle grinder on the edge that juts out. You need to grind the edge down to a point that it is half the original thickness. Create an angle that's no more than 60 degrees with the grinder.

3. Remove the metal stock and replace it with the other side. Turn the metal over so that the side that overlaps is exposed. You're grinding opposing sides in this case.

4. Repeat the same process on the second piece of metal as you did on the first. Grind the metal down to a 60 degree angle that leaves about half the original thickness where it joins. When you weld a butt joint, preparation of the material is of great importance.

5. Complete the grind on the second side. You now have two pieces of metal that fit on top of one another with no visible height change. The seam is known as a V seam because it resembles the letter "V."

6. Feed the weld into the "V" when you are ready to join the two pieces together. The channel that you created is complete and ready to weld the butt joint.

Tips & Warnings

• When you clamp the metal down to a fixed area, use a welding table if possible. The sparks that grinding metal throws are potential fire hazards.
• Always take all safety precautions when grinding metal. Use approved safety glasses to protect your eyes.