Craftsman 113.201392 Owner's Manual

FLAT WELDINGnff 'lffiff.g_vrt19Figurel ii ]lrf p,.JLETWIELDLAPWELDTACKWELOSFiat welding includes all types of joints in which the weldis horizontal, and the electrode is fed down as m the practicewelds of previous pages. The five types of joints in figure 1can be welded in the flat position.Butt welds on light material should be practiced first onscrap stock. Use 16-gauge mild steel sheet metal (approxi-mately 1/16-inch thick) and 5/64-inch rods wqth the welderset at approximately 30 to 50 amperes. Butt edges of metaltogether and tack-weld approximate]y every three inches(fig. 2). (Tack welds are small beads 1/4 to 3/8-inches inlength.) Place bars of scrap iron under ends of the work toprovide an air space above the table. Simply move the rodin a straight line directly above the edges to be (greedIf the weld burns through in places, reduce the welding cur-rent or increase the rate of travel. Some difficulty may beexperier_ced in starting the arc at these low current settings.However, once the arc Js started, there will be sufficientheat to make a sound weld. After laying a bead, turn thework over and inspect the underside which should also havea small uniform bead. To prevent burning through wherethe edges are not butted t_ghtly together, move the rod backand forth with short quick strokes in the dlrechon of theweld to brTdge the gap and give the metal in the crater achance to solidify (fig. 3).Butt welds on sheet metal hghter than 18 gauge shouldnot be attempted by the beginner without the use of aback-up strip (fig 4) This consists of a bar of copperclamped tightly against the underside of the seam to absorbthe heat of the arc and prevent the weld from burmngthrough. To assure complete penetrahon with butt weldson 8-gauge metal or heavier, a 1/16 to 3/32-inch gapshould be altowed between them (fig 5) Insert a wedge orscrewdriver between the plates when tack-welding to mare-tam the gap, then turn the piece over, so the tack welds areon the undersideUse enough current to melt edges of ploFes to o depth ofat least one-half their thickness Clean off the slag andrespect it for smoothness, penetration and height of rem-forcernent A good weld should have a reinforcement shghtlymore than flush with the surface (f_g 6)- Turn the plateSLIGHTGAP SHEETMETALL____I\RACK-UPSTRIPFrgure 4Figure 3Fcgure 5Figure 7t-.t-- GAPFIRSTPASST_IRD PASS_ SECONDPA_SREIHFORCING_ (WEAVE)_PAS$BlrffWELDFigure 8E V-WELDFigure 9E-BEVELW£LOFigure 10over and weld a slm_iar bead on the other side (fig 71 AhEgher welding current can be used on this s_de as there wsno danger of burning through and fusion with the firstbead will be assuredAlthough butt welds can be made on steel plates up to3/8-inch thick, with a 295-ampere machine using 1/4-inchrod, the same results can be obtained with the 180 and230-ampere machines if edges of plates are beveled (fig B)Metal of almost any thickness can be welded m th_s mannerby depositing a number of beads, one on top of the otheruntil the groove _s completely filled. If the plate can bewelded from both sides, always use a double bevet (fig. 9)]f only one plate _s beveled, the angle should be at 45 de-grees fflg. 10).1-8