If I had a dime for every time I've heard this question..... Epoxy glues like JB weld have nothing in common with welding. There is no comparison. A realistic tensile strength of JB weld is in the range of 1,500 - 3,000 lb. per square in. (psi.) Note that this assumes the glue has a perfectly clean, well-prepared surface to bond to. This is rarely the case. Epoxy glues are also rather brittle by themselves. This means that they may break with little or no warning. This might seem like a lot, until you realize that a typical pine board has a tensile strength(along the grain) of about 3,000-11,000 psi. Therefore, wood > JB weld! The tensile strength of a good weld is on the order of 60,000-80,000 psi. In other words, 20-40 TIMES as strong. A good weld is also "ductile", meaning it can absorb quite a bit of punishment by bending and stretching before it breaks. Also, to say that a square inch of the stuff can support 3,000 lbs is misleading. A person with a long wrench or lever can easily apply 3,000 psi of force to an object. This is due to the principle of "mechanical advantage."