Welding Defects: What is Burn-Through?

If "burn through" is a problem, you must have a document that defines this quality, otherwise it would not be a "defect". If you have a document for defects, you may have one for process control, and one which gives a solution.

You may not have any of these, so, stop the welding process prior to exiting the bottom plane of the material being welded.

"Burn through" is exactly as it sounds. You melt through the metal you are trying to weld and create a big unsightly hole/gap - particularly troublesome with sheet metal / thin plates. It is generally a result of too much penetration caused by having too much heat input in the weld zone. You can correct this problem, with MIG, by reducing the wire-feed speed, which, in turn lowers the welding amperage. Also you can increase the travel speed. Burn-through can also result from having an excessive amount of root opening. To correct this problem, you increase the wire stick-out and oscillate the torch slightly.

What process are you using? MIG, spot, TIG, .............?

Does these articles help?:

http://www.millerwelds.com/education/articles/article101.html

http://www.thefabricator.com/ArcWelding/ArcWelding_Article.cfm?ID=2003

that deserves a GA.

Guest, here's a pic that can help you differentiate between good and bad welding. the one at the far right leads to burn through.

and here's how a burn through looks like at the opposite side: