Tutorial for new welding students

This tutorial is for apprentices and Journeymen with little to no welding experience.

Welding is a major part of the ironworking trade. Every journeymen ironworker should be able to take a basic welding call. California District Council apprentices and journeymen are encouraged to attain their welding certifications.

There are three basic certifications:

  1. A7z Deck papers: These can be attained by plug welding three sizes of galvanized sheet metal to A36 steel (standard iron) using 1/8” 7018 welding rod. This certification is necessary to weld floor and roof deck to bar joists and structural members.
  2. A1 Stick papers: This certification requires that the welder fill a 1” thick groove weld 5” in length in the vertical and overhead position using 1/8” 7018 welding rod.
  3. B1a flux core wire papers: This certification requires that the welder fill a 1” thick groove weld 5” in length in the vertical and overhead position using Lincoln .068 or .072 diameter 232 flux core wire, or equivalent.

It is recommend that the new welder first learn to weld in the shielded metal arc welding (SMAW) process. This is known as stick welding.

Before the ironworker begins the welding process it is necessary to first learn about the safety aspects of welding. Welding has many hazards, foremost of are: heat, light, gasses, and electricity. Other hazards are present and will be reviewed.

Welding Hazards and PPE:

Each welder should have the proper PPE and tools for welding. For specific requirements, check with your apprenticeship coordinator or welding shop instructor. Here is what is recommended

PPE and Safety:

  • Hardhat mounted welding hood with minimum #10 lens.
  • Wear your work clothes: Long pants, cotton or denim, without holes or frays
  • A long sleeve cotton shirt
  • Sturdy leather work boots
  • Hard hat and clear safety glasses
  • Welding gloves
  • Welding jacket (green cotton or leather)

Welding is a process that produces heat, sparks, gasses, and radiant light. Wear pants and shirts that are made of sturdy cotton or denim. Shirts should be long sleeve to protect the arms. Leather jackets, sleeves with a bib and chaps are available for high exposure tasks such as overhead welding. Light weight (green) cotton welding jackets are a low cost alternative to leather. Leather work boots protect the feet. When welding in the shop hard toe boots can protect the feet from injury if something is dropped on them. In each case be sure that your clothing and shoes are in good repair without any holes or fraying.

Welding gloves should be worn when welding. They protect the hands and lower arms. Welding gloves are heavy leather gloves with a long cuff. They are lined with insulating material. Do not handle hot iron with welding gloves as it will damage the leather and ruin the gloves. Use a clamp to carry hot iron.

Welding produces sparks. You should wear ear plugs to keep hot sparks from entering you ear canal, especially when overhead welding. Be sure that your work area is clear of items that could be damaged or ignited, such as brooms, tool buckets, jackets, paperwork, or any other combustible item. Welding sparks will pit glass. Do not let any glass come into contact with welding sparks.

When you weld, smoke is produced. If welding in the shop, be sure that the smoke extractor is functioning and that it is removing smoke produced by the welding process. Welding flux contains chemicals that produce hazardous gasses when burned. Iron may have paint or coatings that release gasses when heated. Melted metals produce dangerous fumes. Breathing gasses and fumes may cause negative short term or long term effects. Be sure that you keep your face out of the smoke plume. If the welding shop becomes smoky, welding should be stopped until the situation can be corrected.

Arc welding produces light that can burn the skin and eyes. Be sure that your skin is covered. Welding burn to the skin is similar to sun burn. Be sure that your welding hood is in good condition. A crack in the hood or just a pinhole of light entering around the lens area can cause flash burn (a dangerous and painful condition where the eyes are burned from the radiant light). You can get flash burn from reflected light such as two welders welding back to back and the light reflecting from inside of the hood. The minimum darkness of lens for stick welding should be a # 10 lens. Inspect the lens to be sure it is not chipped or cracked. You can avoid pitting the lens by making sure that there is a replaceable plastic lens on each side of the welding lens. If you have a flip up window on your hood there should be a clear plastic lens in the hood. If you are using an auto darkening lens you will be exposed to a minimal flash each time that you strike an arc. Be sure that the hood is in good working order and that the delay and darkness settings are correct. Some of these hoods have batteries that need to be maintained. Always wear safety glasses underneath the hood. Always close welding curtains and use barriers to protect people from arc flash.

The welding arc is created by electricity. There is high AC voltage going into the machine, usually 220 and up to 440 volts. Exposure to this can be fatal. Coming out of the machine is DC current. Voltage is usually less than 25 volts when welding. Always inspect your machine, leads, and work area for any exposed wires, poor connections, broken or burned insulators, weak springs in the clamp or stinger, or damage from abuse. Make sure that your clothing and gloves are dry and that there is no water leaking or sitting in your weld area. Electric shock can kill.

Tools:

  • Welding hood with minimum #10 lens for stick (darker for wire welding)
  • Chipping hammer
  • Wire Brush
  • Awl, chisel, scribe, or pick
  • Vice grip clamp (to handle hot metal)
  • Flash light

Welding pick or scribeVice grip clamp

Chipping hammer Wire brush

Learning to Weld:

Now that you have the PPE and tools it is time to practice welding. You may have a welding instructor to guide you but this is the process that you should follow:

We will start with SMAW (stick welding). Stick welding is the first certification that you should attain.

  • Secure a welding booth that has a stick welding stinger setup.
  • Find a flat piece of steel at least ¼” thick and about 6” x 6” minimum.
  • Get several sticks of 1/8” 7018 welding rod from the can or oven. 7018 rod should be kept heated in the rod oven to bake out the nitrogen.

Set Your Machine:

Be sure that the stinger is plugged into positive twist connector on the machine. This is DCEP, DC (+), or reverse polarity. It makes a difference. You can hear when the polarity is wrong because the arc makes a crackle sound.

You should be sure that the machine is set to CC mode (Constant Current). This can be found on the weld mode selection button on the Lincoln 350 machines.

You should set your amperage to around 120 amps. You should experiment with the amperage to see what feels best for you. When the machine is set right the slag is very easy to remove. Use a piece of scrap metal to get your machine set.

Strike the arc like striking a wooden stick match. When the arc is struck pull the rod about ¼” away from the work. When the arc stays lit you can move the rod very close to the work then start to run the bead by dragging the rod at about a 60 degree angle away from the arc. If the rod sticks you may not have enough amperage or you are holding too close to the work when you start the arc. Look at the melted puddle when you weld, not the arc, you can see the molten metal behind the arc.

Set your machine like the one pictured below:

There are four welding positions that you should be aware of.

  1. Flat
  2. Horizontal
  3. Vertical
  4. Overhead

You will first start in the flat position. Lay the plate on the welding table flat. The ground should be connected to the piece that you are welding or to the table close to your work. If the ground is not good it may cause the arc to behave in unexpected ways. If the ground clamp gets really hot, you may have a bad ground.

To begin: practice running stringer beads on a flat plate in the #1 position. Tie each stringer bead into the last bead.

Continue to do this until you fill up the plate. You can run beads on top of the beads transversely to gain more practice.

About The Use of Welding Rod and Practice Steel:

Welding rod and practice steel are both very expensive. When using welding rod, burn the rod down to within about 2” of the stinger. If you burn it all of the way down you could burn and damage the insulator on the stinger. It is wasteful to discard a welding rod that you can still weld with. If you stop a weld and still have rod to burn you should break off the flux cone with your welding glove and start your next bead with that rod. It is good practice to restart a weld in the middle of a bead. With time you will master this technique. If you should stick a new rod and break some flux off of the end,that rod can be struck on a piece of scrap until the un-fluxed rod burns away and the rod runs normally. Don’t throw it away.

Never use new steel to practice on unless the instructor gives it to you or you bring your own. Always try to find a piece of scrap iron that you can practice the kinds of welds that you want to practice. Weld on a piece of scrap until there are no more clean places to weld.

If you weld pieces of scrap together, for instance to create a Tee or groove configuration, keep them to a size that is easy to handle. Many people keep welding scrap pieces together until they have awkward conglomerations that are very heavy and have caused serious foot injuries when dropped off of the welding table or post support.

When you tack pieces to the welding post jigs for placement in the vertical or overhead position, be sure that your tack weld is sufficient, but not to where it will not break off when you want it to. Never weld to part of the fixture that is not supposed to be welded to. When you are done welding in a booth, remove your work and sweep off the table. Put the stubs in the proper container. Sweep the floor in your area. Grind down any tacks that you put on the weld attachment angle or plate. Turn off the machine, lights, and extractor. Properly coil your leads. Leave the booth in better condition than when you started.

Once that you master flat welding it is time to practice other positions. During practice you will likely be making fillet welds (welding into the corner of a Tee section. Groove welds are not too much different but you fill a groove between two plates. This is how you will be tested. If possible set up plates as illustrated below. Practice in all four positions until you are confident to test.

To practice for deck welding or the A7z test, cut some scrap deck or galvanized sheet metal of appropriate thickness, place the sheet metal flat on top of some A36 steel at least ¼” thick. Weld through the deck using a circular motion. Be sure that you burn through the sheet metal and into the base metal. This can be difficult on thick sheet metal (16 gauge). Keep practicing until you can create a 1/2” diameter plug weld that is slightly higher than the sheet metal and free of defect. There should be 3/8” penetration into the base metal.

To determine the proper settings of amperage be sure to read and understand the welding procedure that you are practicing for. They should be posted in your welding shop or can be obtained from the welding instructor or coordinator.

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