Arc Welding Introduction

This is the content required for an introduction to our welding transformer - reading this does NOT replace the mandatory session with a tutor! It will make it a lot quicker though ;-)

If you need this Introduction, please reach out to the following tutors: Lukas, Johannes, Luzian, Patrick

Let's begin! First off, make sure you have read the machine's wiki page.

Safety

Personal protection:

Make sure you cover yourself completely, there should be no exposed skin at all!

• welding jacket
• welding gloves over the jacket
• ideally also a fireproof apron against molten metal drops and as additional radiation protection
• robust shoes against glowing hot beads: sandals or sports shoes with mesh top do not provide sufficient cover

Protect your eyes with a properly adjusted welding helmet during welding, and at least goggles when inspecting the weld or hammering & brushing off slag (it may be easiest to just wear goggles under the helmet so you can't forget them!)

Dangers	Precautions
CRITICAL HAZARD - extremely bright arc light damages eyes, risks include permanent blindness if used without appropriate protection UV radiation burns exposed skin radiation can be reflected off surfaces	wear proper personal protection (see above) not all fabrics offer enough UV protection for the high doses experienced immediately stop if anything seems to be wrong with the welding helmet make sure nobody else is exposed to your arc
extreme heat splattering molten metal workpiece heats up a lot electrodes (stick or wire) and other equipment also heat up	make sure there are no gaps in your personal protection, e.g. between pants and shoes or jacket and gloves wear only cotton clothing - synthetics could melt to your body do NOT touch hot stuff, even welding gloves just tolerate so much heat (don't ruin them) so use pliers to manipulate your workpieces if you have to
fire hazard Sparks can ignite combustible material workpiece can reach auto ignition temperature of its coating or residues welding gun/electrode remains hot after welding and might ignite something oil barrels and gas-tanks can contain explosive air fuel mixtures	know where the nearest fire extinguisher is located remove all easily combustible materials from your work area make sure your workpiece is clean turn off the transformer and be mindful where you lay down your electrode/welding gun only work on containers that are definitely empty
toxic fumes (e.g. ozone, flux components, nitrous gases, heavy metal particles) galvanized steel (verzinkter Stahl) releases zinc oxide when welded which can give you "metal fume fever" [1] stainless steel releases hexavalent chromium (carcinogenic) other coatings may also release all sorts of unknown compounds when vaporized	grind away any surface coatings (e.g. galvanization, paint) before welding, they could generate harmful fumes or at least obstruct your weld take care of good ventilation - Use BOTH exhausts of the welding enclosure; but even that might not be enough for long sessions or difficult materials! Also, you should obviously avoid breathing in the fumes. "If the air in your breathing zone is not clear, or if breathing is uncomfortable, check to be sure the ventilation equipment is working and report concerns to a supervisor" [2] stop immediately if you are experiencing nausea and report the incident to a supervisor
non-toxic gases can cause suffocation can accumulate in enclosed areas as most are denser than air	shut the gas bottle's main valve after you are done do not weld in a pit as fumes might accumulate
MIG/MAG: high pressure gas tank can explode can fall over, causing the valve to break	handle with care do not subject to heat always secure the tank so it can not fall over (e.g. chain to the Welding Area's stone wall)
exposed electricity (up to 60 V DC, 150+ A) still below zulässige Berührungsspannung - minor risk of shock some transformers employ a high voltage pilot arc that can jump air gaps and travel through gloves	reduce the chances of electric accidents: [3] make sure you are isolated (proper dry gloves, shoes and/or floor mat) from the workpiece, especially do not touch the electrode and the workpiece simultaneously unplug the welding transformer when not in use do not use two welding transformers on the same workpiece in case of electric shock, always make sure to visit a doctor! SMAW: remove the welding electrode before putting the holder down (NEVER on your workpiece or anything connected to the transformer!)
equipment may overheat	if you use a cable drum, make sure to unwind it completely - a wound cable drum will induce current and heat up the cables, which may lead to a molten cable coat with high risk of a exposed mains wire if an electrode gets stuck on the workpiece and you can not remove it quickly, turn off/disconnect the transformer and then remove the electrode and figure out better settings or switch to a new electrode
accidental/negligent arc UV light and sparks can be a dangerous surprise when not expected the trigger/pedal can be pressed by accident	wear protection prevent accidental arcs store gun/electrode on a heat resistent & electrically isolated spot unplug the welding machine when not in use
sharp & hot slag pieces after welding, removing slag can be dangerous (pieces fly around when hit with a slag hammer)	keep wearing a welding mask or safety goggles when manipulating the workpiece between welding sessions
metal dust can short the transformer	make sure the transformer does not suck up metal dust from grinding, especially the ones with active cooling

Suggested Reading

Besides these safety notes, you should read our page about welding electrodes.

These websites may also be interesting:

• BGHM: Schweißen und verwandte Verfahren (DE) - detailed safety information
• BGHM: Arbeitsschutz kompakt - Lichtbogenhandschweißen (DE) - nice short safety overview, "checklist" style
• five potentioal welding safety hazards

Demonstration

The tutor will show you these steps in detail:

• check welding helmet settings
• set up your work in the welding enclosure
• turn on BOTH exhaust systems
  • The trunk only ramps up to high if you temporarily obstruct the airflow
• try striking an arc and depositing metal on a scrap piece (e.g. in the shape of your initials)
  • it's good to experience the often scary sensation of your first arc ignition with your tutor ;-)
  • once there is a steady arc, push forward and make little circles in the weld pool to "mix" the workpiece(s) with the deposited material

Waiting List

This introduction takes longer than many others and usually can't be done spontaneously during regular opening times. If you would like to receive it, please add yourself to >> this list << and we will find a good time once a few members are on it!