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 ;-)

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

Safety

Dangers

• extreme heat
• CRITICAL HAZARD - extreme bright arc
  • light damages eyes, including permanent blindness if used without appropriate protection
  • UV radiation burns exposed skin
• splattering molten metal
• sharp & hot slag pieces
• exposed electricity (up to 60 V DC, 100+ A)
  • still below zulässige Berührungsspannung - minor risk
• 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
• in some cases the electrode may get stuck on the workpiece upon striking an ark
  • if you can't remove it from the workpiece quickly, turn off the welder and then remove the electrode
  • usually this can be caused if the setting on the welder is wrong or due to old electrodes

Precautions

• wear proper personal protection:
  • cotton clothing - synthetics could melt!
    • cover yourself completely, there should be no exposed skin at all
  • welding helmet during welding, goggles when hammering & brushing off slag
  • welding jacket
  • welding gloves over the jacket
  • ideally also a fireproof apron against molten metal drops and as additional radiation protection
• immediately stop if anything seems to be wrong with the welding helmet
• 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 - our welding enclosure is open at the top but that alone might not be enough for long sessions or difficult materials! Also, you should obviously avoid breathing in the fumes.
• reduce the chances of electric accidents: ^[2]
  • make sure you are isolated (proper 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
  • remove the welding electrode before putting the holder down (NEVER on your workpiece or anything connected to the power!)

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:

• set up your work in the welding enclosure
  • red curtain far away
  • close gaps, e.g. with spring clamps (long-term solution needed!)
  • bring a light with you, if necessary
• 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!