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

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 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	wear proper personal protection (see above) immediately stop if anything seems to be wrong with the welding helmet
extreme heat splattering molten metal sharp & hot slag pieces	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
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 - 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. "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]
exposed electricity (up to 60 V DC, 100+ A) still below zulässige Berührungsspannung - minor risk of shock equipment may overheat	reduce the chances of electric accidents: [3] 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!) if you weld for longer, make sure that the cable drum is completely unfolded - a winded cable drum will induce current and heat up the cables, which may lead to a molten cable coat.
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/disconnect the transformer and then remove the electrode	use the correct setting on the transformer or switch to a new electrode

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!