A few of you studying this are about to take your first TIG welding certification take a look at within the aerospace trade. Perhaps you might be transitioning from one other trade like pipe welding the place you welded stainless and carbon metal pipe, or meals service the place you welded stainless-steel sheet steel. Both method, let me inform you a couple of suggestions that may assist you to prepare:
Every thing is thinner and smaller. The tig torch, electrode, filler wire, and probably even the tig welding machine shall be smaller than you might be accustomed to. In pipe welding for instance, a 1/eight inch rod is taken into account the large tig welding rod. In Aerospace tig welding, a 1/16 inch rod is large.
Every thing must be cleaned higher. All joints are usually x-rayed in an aerospace tig welding certification take a look at. Metals like titanium, aluminum, and magnesium are susceptible to porosity. Bear in mind the three C’s …clear, clear, clear. Particularly necessary is submitting the sheared fringe of steel that shall be welded. That sheared edge seems fairly clear however it’s a entice for oil and corrosion merchandise. File it and if you suppose you could have filed it sufficient, file some extra.
Every thing makes a distinction. Little issues like the dimensions of your tack welds, the way you place the take a look at plates within the fixture, how a lot stream price is used on the purge gasoline, angle of torch, angle of filler steel rod, what sort of abrasive you utilize to wash the steel, how pure the argon or different shielding gasoline is…you get the image. Like my outdated coach used to inform me…nothing is honest, however the whole lot issues.
Every thing must be shielded higher. The recent tip of the filler rod will put oxides in your puddle. You will get away with slightly of that in pipe welding stainless and gentle metal, however it would kill you when welding one thing like .020″ 15-7 precipitation hardening stainless or .032″ inconel 718. To maintain the top of the rod completely shielded , use a tig cup that’s at the least 3/four inch id. With a diffuser that gives a pleasant tender blanket of argon shielding to the puddle. ..and you have to take a look at it on a scrap piece of titanium to ensure it’s working earlier than lighting up in your tig welding certification plates.
Three extra suggestions for passing an aerospace tig welding take a look at…
- About 1 amp per 1 hundreds of thickness welded will get you within the ball park. Set the tig welding machine amperage accordingly plus about 10 extra amps simply in case and use the foot pedal to regulate. It will hold you out of bother by limiting your amperage. often a bead width of four occasions the thickness welded will get the penetration wanted for butt welds.
- Use the smallest electrode that may get the job executed. And sharpen it actually good with scratches working lengthwise. lengthy tapered works higher for actually skinny (.020″) and fewer of a taper is best for thicker welds
- Use the smallest filler wire that may work with having to feed an excessive amount of. Too large a tig welding rod will draw an excessive amount of warmth out of the puddle and can trigger you to make use of extra amperage than is required . Too small a filler wire will trigger you to feed an excessive amount of and also you cant sustain.