SWITCH AS 4217503 - Caterpillar

Do not index (turn) the boom during the tack welding procedure.
(11) Check the alignment of bracket (5) to make sure it is still correct. If the alignment is correct, tack weld the remainder at locations (H) on the top and bottom. (12) Run-off tabs (11) must be used during final welding of the bracket. Make the run-off tabs from pieces of .25" (6.4) plate. Tack weld the run-off tabs to the top and bottom of the boom and bracket (5) as shown.(13) Use 1/8" (3.2) E7018 Electrodes at 140 30 amps DC+ for step 14 of the following weld procedure. Start all welds at locations (J) on the run-off tabs. (14) Weld the first pass a minimum of 3.0" (76) on both the top and bottom of the boom at locations (J) as shown. Weld the first pass at locations (K) on both the top and the bottom of the boom. Repeat (do again) the above procedure until approximately 33% of the volume of the weld is complete. Locations (J) must be free of weld craters (defects). Stagger all weld tie-ins (do not start and stop the welds in alignment).(15) Use 5/32" (4.0) E7018 Electrodes at 220 30 amps DC+ for the remainder of the weld procedure in this step. Weld the top joint until it is approximately 66% complete. Index the boom 180° and finish the weld on the bottom joint. Index the boom 180° and finish the weld on the top joint. All welds must be smooth and flush with the boom when complete. Remove the run-off tabs and grind the ends of the welds smooth and flush with the sides of the boom. Remove and repair all surface defects. (16) Cut a .38" (9.5) gap at the four corner locations (L) between the boom and bracket (1). Use a fillet weld with 100% penetration at locations (L). Weld the two lower locations first; index the boom 180° and weld the other two locations. Grind the welds smooth with the boom and bracket (1). IMPORTANT: There must not be any undercuts or slag deposits at locations (L). A good weld at these locations is especially important in the repair procedure. (17) Use a .31" (7.9) fillet weld along locations (M) to weld the top and bottom plates of the boom to the in