Informal term for fusion into the joint walls or previous passes, judged by eye, by the sound of the arc, or on a macro etch. Good burn-in means the arc dug into both sidewalls instead of piling metal on top. Too little leads to lack of fusion and cold lap; too much can cause undercut or burn-through on thin material.
You're getting no burn-in on the sidewall, slow down and point the wire at the bevel.
Also heard as
- burn in
- bite
- dig
Related terms
Penetration
How deep the weld fuses into the base metal or the joint beyond the original surface.
Tie-in
How well a weld fuses into the base metal, the bead beside it, or the end of an earlier weld.
Lack of fusion
Weld metal that failed to fuse with the base metal or a previous pass at some boundary.
Cold lap
Shop term for weld metal that rolls over onto the base metal or a previous bead without fusing to it.