Those little circles of steel aren't spots; they are puddles of strength holding your world together. Do you have a horror story of a plug weld that failed, or a trick for getting them perfect every time? Let us know in the comments below!
You need to "witness" the bottom plate melt. On your first tack, hesitate for half a second. If you see the base metal turn shiny and liquid before you add filler (or before your MIG wire hits), you are golden. If you just hear spatter, you are too cold. When Not to Use a Puddle Weld Puddle welds are amazing for overlapping joints, but terrible for butt joints (two pieces edge-to-edge). They also struggle with thick-to-thin transitions. Trying to puddle weld 1/4" plate to 22-gauge sheet will result in the thin metal blowing away every time. Final Verdict The puddle weld might not have the flashy appeal of a TIG-dabbed stack of dimes, but it is the backbone of modern manufacturing. For the home fabricator, mastering the plug weld is the secret to restoring a classic car or building a rust-proof trailer deck. puddle weld
If you’ve ever wondered how the floor pans are attached to the frame of your car, or how a sheet metal bracket is secured to a hollow tube, you’ve likely seen a puddle weld. Here is your complete guide to what it is, why it’s used, and how to do it right. A puddle weld is a method of joining two pieces of metal—usually where one piece overlaps the other—by melting through a hole in the top layer to fuse it to the bottom layer. Those little circles of steel aren't spots; they
Instead of welding the outside edges of the overlap (which can look messy and trap moisture), you drill or punch a hole in the top sheet. You then direct your welding arc into that hole, creating a "puddle" of molten metal that bonds the top sheet to the underlying parent metal. When you finish, the hole is filled flush with weld metal. You need to "witness" the bottom plate melt