Fume guns are excellent source capture solutions for weld fumes. When used properly, they can capture up to up to 95% of weld fumes. Here are two major factors that affect the capture rate of a fume gun:
- Holding position - It is important to hold a fume gun at the correct angle. This allows the capture nozzle to be in the proper position as the fumes are being created. The location matters as well—a fume gun does not work very well upside-down, since weld fumes rise. As most welders know, a little training goes a long way and can significantly improve the capture efficiency of the fume gun.
- Extraction rate - Fume guns capture weld fumes using high pressure and low CFM (cubic feet per minute). The suction hose on the gun is attached to a high-vacuum (hi-vac) collector, which provides strong suction through the small hose. The CFM of a fume gun is much lower than that of, say, a fume arm—60 CFM versus 600-1,200 CFM, respectively. The suction rate must be properly balanced so that it does not interfere with shielding gasses, leading to poor-quality welds.
It should be remembered, however, that fume guns are not appropriate for all applications. For example, in confined environments, residual weld fumes can build up and expose a worker to excess fumes if no other protections or ventilation units are in place. Weld seams often emit a certain amount of smoke after welding, and the fume gun won’t capture all of it. This is especially the case when welding materials that result in excessive smoking. In these situations, an ambient system may be needed to collect leftover fumes that escape into a facility’s air.