There is not enough weld testing being done in the booming welding hobby field. If a new welder doesn’t know what they are doing, they may get themselves, or someone else hurt or killed. The cable TV shows have done a miserable job of getting that message out, while allowing all kinds of non-existent safety practices and violations to be aired! I’m picking on cable TV because while they’ve done a fantastic job of putting welding in the spotlight, they’ve done a miserable job of educating people about the importance of safety, and sound welds.
The only way you know you are making sound welds is to see if they pass tests.
Besides the possibility of getting hurt while welding using unsafe practices, there is also the possibility of getting hurt when a home hobby project fails. A prime example is when someone has an unsound weld fail on a trailer going down the highway at 70mph. I’ve actually seen a spare tire rack break shooting the tire down the road like a missile. Luckily that time no one was hurt, but I’ve heard of people getting hurt and killed by similar incidents, including a one-year recovery from a fall from a faulty deer stand!
New welders should learn about testing, and be able to pass weld tests before taking on projects that could affect public safety
Anyone can go out and buy a welder for a couple hundred bucks and start building projects. But without their welds being tested, there’s no telling how sound they are. A good comparison is a teenager buying one of the new 600 cc sport bikes with over 100 horsepower. Just because they can afford to buy one, does not mean they are qualified to operate one. Just because you can run a bead, that does not mean you are putting down a sound weld unless your welds have been previously tested and consistently passed.
There are three different types of weld tests done in industry including visual, destructive, and non-destructive.
A visual weld test is using your eyes to examine the completed weld. You are mainly looking for a smooth, uniform weld free from cracks, holes, concaveness, lack of penetration, undercut (the cardinal sin of welding), and other defects. Although a microscope or magnifying glass may be used, only the surface can be examined when using visual weld tests. Therefore a visual weld test although being the easiest, is also limited in its scope.
A destructive weld test destroys the metal that has been welded on. There are several different types of destructive tests including tensile shearing, breaking, nicking, etching, impact, and acid. The most common structural weld test is the guided bend test. Destructive tests show both the surface and inside of the weld.
Most tests I took in the field working on high-rises, power houses and the like were guided bend test.
Lastly is the non-destructive weld test which does not tear up the welded metal and includes liquid dye penetrant, radiographic, ultrasound, magnetic particle, and eddy current testing. These are done on erected structures where it would not be practical to destroy the metal.