Lesson 1Choosin TIG vs MIG fi each joint: criteria fi posts-to-baseplate, handrail joints, an infill barsCompares TIG an MIG fi typical aluminum joints such as posts fi baseplates, handrails, an infill bars. Discusses access, appearance, deposition rate, an skill level fi guide process selection an parameter setup.
Process comparison: deposition and controlPosts-to-baseplate joint process choiceHandrail and infill bar joint examplesAccess, position, and appearance factorsCost, productivity, and rework trade-offsLesson 2Common aluminum weldin defects: porosity, lack a fusion, hot crackin — causes an preventive actionsIdentifies common aluminum weld defects such as porosity, lack a fusion, an hot crackin. Links each defect fi causes like contamination, poor fit-up, or heat input, an outlines inspection methods an corrective actions.
Porosity causes, detection, and preventionLack of fusion from low heat or techniqueHot cracking and solidification controlUndercut and overlap on fillet weldsVisual and NDT checks for aluminum weldsLesson 3Weldin sequences an techniques fi minimize distortion: tack strategy, stitch weldin, alternatin sidesShows how weldin sequence, tack placement, an bead pattern reduce distortion in aluminum. Covers stitch weldin, backstep techniques, alternatin sides, an presettin parts fi counter expected shrinkage.
Tack weld spacing and size for restraintStitch and skip welding on long jointsAlternating sides to balance shrinkageBackstep technique on thin platePresetting and cambering parts before weldLesson 4Joint assembly an clampin fixtures: minimizin gaps, use a angle fixtures an backinExplains how joint assembly, fit-up, an clampin fixtures affect distortion an weld quality. Covers minimizin gaps, usin angle fixtures, backin bars, an adjustable jigs fi hold alignment durin multi-pass aluminum weldin.
Fit-up tolerances and gap controlAngle fixtures for square and miter jointsUse of backing bars and backing stripsAdjustable jigs for repetitive assembliesPreventing movement during tack and weldLesson 5Current types an polarity: AC vs DCEN vs DCEP an when fi use eachExplains AC, DCEN, an DCEP fi aluminum weldin, linkin polarity fi cleanin action, penetration, arc stability, an electrode heatin. Covers typical TIG an MIG setups, machine settings, an how fi choose polarity fi different joint types.
AC balance and cleaning action on aluminum oxideDCEN for specialized aluminum applicationsDCEP effects on tungsten heating and cleaningPolarity selection for TIG vs MIG processesMachine setup checks for correct polarityLesson 6Pulse weldin considerations: benefits fi heat input an control, when fi applyCovers pulse weldin principles fi aluminum, includin peak an background current, frequency, an duty cycle. Explains benefits fi heat input control, out-a-position work, thin sections, an how fi select pulse programs or manual settings.
Pulse parameters: peak, background, frequencyBenefits on thin aluminum and gap bridgingUsing pulse for out-of-position weldsSelecting factory pulse programs on power sourcesManual tuning of pulse for specific jointsLesson 7Shieldin gas selection an flow rates fi aluminum weldinDescribes shieldin gas options fi aluminum TIG an MIG, focusin pon argon, helium mixes, an flow rate selection. Addresses nozzle size, gas coverage, draft protection, an troubleshootin porosity or sootin from poor shieldin.
Pure argon for most aluminum TIG and MIGArgon–helium mixes for thick sectionsTypical flow rates by process and nozzleGas lens, cup size, and stick-out effectsDraft shielding and leak troubleshootingLesson 8Interpass cleanin an oxide removal durin weldinExplains why interpass cleanin is critical pon aluminum, focusin pon oxide removal, hydrocarbon contamination, an moisture. Compares stainless brushes, scrapin, an light grindin, an defines when an how often fi clean between passes.
Aluminum oxide properties and weld impactDedicated stainless steel wire brushingSolvent cleaning and degreasing stepsLight grinding and scraping without gougingCleaning frequency between weld passesLesson 9Typical parameter ranges: amperage, travel speed, electrode size, wire diameter examplesProvides typical startin ranges fi amperage, travel speed, electrode size, an wire diameter in aluminum TIG an MIG. Emphasizes adjustin parameters fi thickness, joint type, an position while avoidin common setup errors.
Amperage ranges by material thicknessTravel speed targets for TIG and MIGTungsten diameter and tip preparationWire diameter selection for spray transferParameter adjustment for position changesLesson 10Heat sink an coolin strategies: chill bars, temporary clamps, controlled coolin pausesDetails how heat sinks, chill bars, an clampin reduce distortion an burn-through in aluminum. Covers backin bars, copper shoes, coolin pauses, an water-cooled fixtures, wid guidance pon when fi allow controlled heat buildup.
Chill bar materials and contact requirementsTemporary clamps to control fit-up and warpBacking bars and copper shoes for root supportPlanned cooling pauses between weld passesWater-cooled fixtures and safety concerns
