Wiki
Note: This is just a very general overview of the Welding Intro class curriculum, primarily used as a prompt when instructing the class live. This article is (obviously) not meant to replace being properly trained on the equipment.
WHY LEARN?
- it’s super cool and feels awesome
- welders build the world
- very employable skill
- can look incredibly awesome
- it’s a lightning gun!
- very easy to get ok at it; hard to master
- might be the only reason to keep you around in the apocalypse
SAFETY
You need to bring/wear:
- Closed toe shoes
- It’s a good idea and also a shop-wide rule
- Long pants
- Not just for splatter; you can get sunburn too.
- Non-synthetic fabrics
- Cotton may burn, but synthetics melt
- We provide weld jackets, gloves, and helmets
- general metal handling (heavy, sharp, hot, rusty); common types of gloves
- arc flash, going blind, testing your hood
- burning the shit out of yourself, jackets and leather (welding arc can reach 24,000 degrees science / 43,000 degrees freedom)
- sparks and spatter, catching shit on fire, awareness of what’s around your hood
- electrical dangers; describe average voltage/amperage ranges. 1A per thou average.
- zinc poisoning, fume control, ventilation (and how it affects shielding gas)
- gas cylinder storage, pressure container dangers
- Where are the fire extinguishers?
- One above the grinding table, another outside the entrance to the metal shop
- First aid kits:
- Weld-specific kit with burn treatments above grinding area
- Main first aid station in woodshop
MIG WELDING
- NOT going to cover stick, tig, brazing, spray transfer, or other processes here.
- only covering flat position; there is also vertical, overhead, pipe, etc.
- not going into detail on joint types; fillet, lap, groove, plug, butt, corner, tee, edge, etc
- Also only focusing on mild steel, no fancy materials like stainless or aluminum.
- MIG welding = hot glue. Super easy to get OK at, will take you a few years to actually get good.
- overview of how a MIG welder works; basic circuit, DCEP/reverse polarity, ground clamp, gun, ER70S6 wire, nozzle, spool, gas, etc.
ANCILLARY FABRICATION
- Spinny sharp thing safety; loose hair and clothing, face shielding, keep hands away from blades, cut metal is sharp and hot
- chop saw some angle iron coupons
- bench grinder on the edges, mention beveling
- clamp and angle grinder to remove mill scale from plate; what is mill scale?
- Now we’re ready to weld
USING THE WELDER
- how to turn the welder on
- Check ground plug
- how to set gas flow – 15-25 CFM to start, adjust as needed
- set wire feed rate and amperage
- appropriate wire stick-out distance
- how to shut the welder off
- Coil wires and leave on hooks
- Turn off gas
- Replace dust cover
TIME TO WELD
- lay plate on table, have students tack edges down
- demonstrate warping with some flat bar or rod; this is why we tack first. Mention average thermal expansion/contraction rates for steel
- cover gun positioning, posture, dry run; lay a 1″ bead down; watch the weld puddle closely, this is where the action happens
- stick a couple coupons to the plate, attach some stuff stuff to other stuff
- practice fillet welds; demonstrate stringer vs weave
- general practice time. describe what we’re looking for in good welds; penetration, porosity, buildup
- If we have adequate time and materials, show blow-through and how to fix it; bridging gaps
CLEAN UP
- grind off our tacks, clean up the table
- put everything away, sweep
- discuss where to acquire metals in town
- resources on how to get better
- Q&A