Tools/mig/induction

From rLab Wiki

Some of the tools at the Hackspace are potentially hazardous to use, for these tools members are required to have an induction before they can use them. Inductions provide the most basic information on how to safely and effectively use the simpler functions of the tools, we appreciate that some members may have professional experience on some of these tools and in this case please tell your induction provider and the induction may be very reduced and just cover any risks or procedures specific to rLab. Some tools have multiple levels of induction in order to cover more advanced uses of that tool without making the basic induction take too long, higher induction levels will introduce some of the more advanced features of the tools but as with all inductions are only intended to provide basic information on the capabilities of the tools and how to use them safely. Some members of rLab may be willing to offer more detailed tuition beyond basic induction level or offer guided practice sessions in exchange for beer money or assistance on their own projects.

For all tools you are only required to take level-1 induction before use, after that you may perform any task that you feel confident you can do safely, higher levels of induction may be useful to you in performing more advanced operations but are not required before doing tasks covered in them so long as you're confident of your ability to handle those tasks without risk to yourself, others, or the tool.

PLEASE NOTE : All induction providers are volunteers who are providing inductions to the best of their ability but are NOT qualified instructors. Inductions are provided on a best-effort basis but you and you alone are responsible for your safety while using the tools and for satisfying yourself that you can operate the tools safely. There are professional training courses available from various providers in Reading and the surrounding area if you feel they are appropriate for the level of work you intend to undertake. Reading these notes is NOT a substitute for an in-person induction.

Note for wiki editors : Please do not edit induction pages unless you are one of of the people that gives that induction

MIG Welder induction - Level 1

Level 1 induction in intended to cover the basics of how to use the MIG welder. It should cover basic safety information and how to use the welder effectively on mild steel in positions 1G and 2G/F. People undertaking MIG induction need to have overalls or other non-flammable clothing that covers all exposed skin except for head and hands, clothes are likely to get burn spots on them. Wear stout shoes or boots, no open shoes allowed. If you have any metal you'd like to practice on then please bring it with you so long as it's plain steel with no galvanised coating or paint but if you don't have any then we usually have suitable scrap around to practice on. There's no charge specifically for the induction but normal welder usage charges apply, you should expect it to cost around £10 for the induction and a bit more if you spend some time practicing afterwards which is strongly recommended

Before the induction the inductor should prepare coupons consisting of 4 sheets of 2mm mild steel sized 200mm x 50mm and one of which has been drilled with 6 x 10mm holes. All edges cleaned and deburred but mill-scale left on the sheet. One additional bit of steel, thickness >1.5mm and size > 150mm x 150mm will be required for stringer bead practice and faults demonstration.

Topic Detailed contents Rationale
Types of welding available
  • MMA - Fast, thick, dirty, good outdoors, medium-high skilled
  • MIG - Fast, medium thickness, relatively clean, low-skill requirement
  • TIG - Slow, Neat, special materials, super-clean, high-skilled
  • Gas - Most similar to TIG but for safety reasons we won't be doing this at rLab
  • Forge - V.V.Slow, good for big flat welds, high-skilled
  • Spot - Tiny spot welds for joining plate, low-skilled
Which technique to use for which weld
How it works
  • Machine strikes an arc between the work and a consumable wire electrode, melting a pool of metal
  • Wire dips in and out, adding metal to the pool
  • Gas shields the hot metal from the air
  • Earth clamp provides return path
Basic process details
Safety
  • Fire hazard
    • Metal sparks and radiant heat/light
    • Clear area of flammable materials, be aware of solvents and vapors
    • Having fire extinguishers handy and what types are suitable
  • Arc-eye hazard to you and people around you
    • Using an auto-darkening welding mask
    • Suitable settings on mask (9-11, 12 maybe - start at 10 and adjust)
    • Shouting "Eyes" if there are other people around
  • PPE - Overalls, stout shoes, thick leather gloves, mask, dust protection when needed, Cover all exposed skin or you'll regret it!
  • Care with Galvanized steel, risk of metal-fume-fever
  • Gas safety
    • Enclosed spaces
    • Low spaces
    • Fumes
  • Electrical Safety
    • The voltage is low, but you still don't want to touch it
    • Mind what you point the torch at
    • Power cuts off as soon as the trigger is released
    • NO RINGS, NO WATCHES!!
    • Users with implanted medical devices should seek doctor's approval before welding, it's not usually a problem, but please do check
    • The welder plugs into a 16A socket, there is a 16A trailing socket on the pillar, it's fed from the bandsaw power point
    • If the bandsaw is used at the same time it may trip the breaker
    • Use only suitably rated industrial extension leads, they're in the desk drawer B1B
    • Extension leads are a trip hazard, warn people
    • If something does go wrong, shut off power before anything else
Using the equipment without harming self or others
Preparing to weld
  • Check metals are suitable
    • Mild steel only at level 1
    • Beware of galvanized steel
    • Beware of lead-bearing and copper-bearing paints
  • General angle grinder safety
    • Types of disc
    • Inspecting grinder and disc
    • Changing the disc
    • Care of position and cut angle
    • Dust protection, eye protection, gloves
    • DO NOT TWIST in a cut
  • Clean up weld area - be aware of burning paint
  • Clean area for earth clamp
  • Beveling edges to form a path for the bead on butt joints
    • No bevel on thin materials
    • Regular 2/3rds bevel most of the time
    • Beveling from both sides for very thick
Proper preparation is necessary for good welds, cover bevel patterns for other weld types later
Machine Description
  • Parts
    • Base unit
      • Power source
      • Wire feed mechanism
      • Shroud
        • Annoying "thread"
        • Cleaning out spatter regularly
      • Tip
        • Screwed in barely more than hand-tight
      • Trigger
    • Gas bottle
      • Types of gas and why
      • Regulator
      • Basic gas bottle safety
    • Earth Clamp
  • Controls
    • Gas Flow
    • Wire Feed
    • More complex controls are available at level-2

Wire type, liner and torch can be changed, but not covered at induction level-1

Covering what all the parts are called and which control does what
How to actually execute a weld
  • Normal welder settings
    • Gas at 8L/min will work for most situations but maybe up to 12L/min when very welding thick materials
    • Navigating the menus and selecting SmartMIG mode
    • Setting wire thickness and plate thickness
    • On very thick materials then you need to be aware that the torch is only rated to 150A so you may need to run quite short duty cycles.
  • Proper position of self and torch, direction of motion
    • Suitable angles to work at (10-20 degrees ideally, absolutely less than 45 degrees)
    • Push welding - Normal, safe option
    • Pull welding - bigger bead, better penetration, lots of grind and risk of inclusion
    • Vertical and overhead welds are things that can happen, but not covered at level-1
  • Correct distance (10mm is good, anything from 5mm - 20mm is probably going to work if you give sMIG time to learn)
  • Trimming the exposed wire to a suitable length if it's over-long or balled up
  • Proper posture for welding
    • Getting comfortable
    • Supporting the cable if needed
    • Chairs if they help
    • Being comfortable and able to move without stretching is critical for good welds
    • Resting your other hand on something to use as a guide
  • How the pool forms (Only cover dip transfer)
  • Taking the pool "for a walk"
  • Keeping the wire aimed at the nose of the pool
    • Further towards the tip of the pool = fast move, thinner bead, less penetration
    • Further towards the back of the pool = slower movement, wide bead, deep penetration
    • This is your primary method of regulating the travel speed, change you aim point and the rate the bead moves across the work will change
  • Moving patterns, circles, arc, steady, but not too fast or you'll fool the sMIG feature
  • You may need to adjust the shade of your mask to get a clear view
    • Each shade number upwards cuts the light you see in half
    • The temptation will be to look at the arc, but try to focus on the puddle. The puddle is what you need to control and let the machine take care of the arc.

[Demonstrate a good simple weld bead]

Cover the basic technique of establishing and moving a weld bead
Problems

[Deliberately set up and demonstrate each of these faults]

  • Stabbing and poor penetration - too far away from work
  • Weld sticks to tip - too close
  • Bead sitting on surface - too fast
  • Over-penetration - too slow
  • Blowing holes in material - MUCH too slow
  • Lots of sparks and brown/porous weld - not enough gas or too far away
  • Arc won't strike - Ground clamp not connected
  • Weld moves around erratically - too much gas or influence from holding magnets
Recognizing faults and knowing how to fix them
Practicing a steady bead Inductee practices laying down a straight and steady, well-fused bead on flat stock till competent Getting the basics right
Butt joints
  • Proper grinding and prep
    • Bevels right way up and properly spaced
    • Proper fit-up between parts
    • Option of using backing blocks (temporary and permanent)
  • Using holding magnets and clamps
  • Do NOT tack work to the table
  • Tacking to limit distortion, you are GOING to get distortion
    • Straight, back-track and half-split tack welding
  • Root-weld and multi-pass welding on thick material

[Demonstration and practice till successful]

Executing the most basic weld
Fillet joints
  • Don't need to grind, but parts need to be clean
  • Good fit-up important, will makes things much easier for you
  • Proper torch position and angles
    • Push angle a little steeper than normal
    • Biased towards the vertical plate
    • Weaving pattern, spending more time on upper plate
  • Stitch and alternating stitch to control distortion
  • Pre-compensation for distortion

[Demonstration and practice till successful]

Second most common weld type
Pool Welds
  • Good for joining things that are meant to be bolted in
  • Cleaning up the surfaces
  • Starting from the centre on a small one to ensure fusion to base plate
  • Starting from edge on large pools and may not need to fill it in completely
  • Care with thick base plates as heat dissipation may cause cold-shuts
  • Demonstrate if there's time
Fixing wheels and fittings onto things
Lap joint
  • Lack of need for grinding but must still be cleaned
  • Treat is as two fillet joints
    • But watch out for heat buildup in the edges
    • Extra care if the sheet is thin to watch for balling up
  • Alternating stitch welds to control distortion
  • Demonstrate only if plenty of time and inductee is keen to try
Next joint type
Shutting down and cleaning up
  • MIG welds sometimes require grinding back with an angle grinder to make them neat
    • Wire brush if you don't care about cosmetics
    • Flap discs will tidy up welds that are good to start with
    • Grinding discs will remove messy welds quickly
  • Shutting off the gas before un-hooking the couplings
  • When you're done shut off the power to the welder and putting the leads away
  • Sweeping up and putting everything back where it belongs
  • Working out your total weld length and paying for it
  • Checking how much gas is left and making a post on the group if it's below about 10%
  • Discuss any projects the inductee is working on to provide pointers
Clean up after yourself and pay what you owe!
Final thoughts
  • This has only been an extremely brief over-view of MIG welding
  • Do not expect your joints to be structurally sound or pretty until you have practiced
  • The sMIG feature is providing you a LOT of help on this welder, if you switch to a welder without sMIG you may find things a lot harder
  • If you want to weld aluminium or magnesium alloys, Stainless Steel, Brazing or other techniques then you can look at TIG level 2 or MIG level-2 inductions although it's not compulsory to do level-2 inductions if you've already done the relevant level-1 inductions and if you think you can manage these techniques without further help
  • If you want further tuition then some members of rLab are willing to provide this, but they may charge for it.
Closing comments

Update session for conversion from Clarke 150A unit to ESAB EMP235ic

rLab has recently acquired an ESAB Rebel EMP235ic MIG welder which is considerably more capable than the old Clarke 150A unit but it's controls and operation are a little different so people who've completed induction on the Clarke unit are required to have an update session to be inducted on the EMP235ic. This update session is anticipated to take around 20 minutes.

Topic Detailed contents
Safety Very much similar to the Clarke unit but be aware this machine can output a higher voltage if mis-set. Also as the EMP235ic can output considerably higher currents, darker shades on masks may be called for. This is a 16A unit and should be connected to a 16A or 32A power supply using industrial type extension leads. When using the bandsaw connection point then be aware of the risk of tripping if the bandsaw is in use at the time.
Controls The controls on the EMP235ic are very different, it is controlled via an LCD screen and a menu system. For the level 1 you should only be using the machine in Smart-MIG (sMIG) mode. In this mode you need only tell the welder what size wire you are using and how thick the material to be welded is. You may optionally also set a weld profile but unless you're sure of your needs, leave it on neutral. Gas flow should remain at 8L/min for normal welding operations, optionally increasing to 12L/min for plate above 5mm thick. On very thick materials then you need to be aware that the torch is only rated to 150A so you may need to run quite short duty cycles.
Welding Position, travel direction, and spacing should all be the same, but be aware that the welder often starts out a little rough for the first 1-2 seconds as the sMIG feature learns what you're doing an corrects so if the weld sounds odd when you pull the trigger, DO NOT STOP, give sMIG time to correct before you decide there's a problem. Be aware that although this welder is capable of globular and spray transfer welding mode when in manual settings, globular and spray transfer should be impossible to initiate while in sMIG mode. Weave patterns should be executed more slowly than usual to avoid confusing the learning feature.
Welding problems In previous inductions a range of problems were demonstrated for you to learn to recognise. With this new welder in sMIG mode many of those problems are now impossible. You no longer need to consider wire feed rate issues or power issues as those are chosen automatically. Travel speed and torch position still need to be considered as sMIG cannot completely correct those for you although it will give you considerably more margin for error and still get a good weld.


MIG Welder induction - Level 2

Level 2 induction should cover more advanced uses, there will be a charge of £25 for level-2 induction to cover the increased cost of sourcing materials and trainer time associated with these more complex issues.

Main level 2 induction

  • Going into Manual mode on the welder and suitable settings to use
    • How to select manual mode
    • Selecting the proper material in use on the menu
    • Adjusting wire feed rate and voltage, simpler welders may use an arbitrary scale for voltage, or may not be constant voltage at all and use an inductor to control things. In that case you'll just have to feel you way through finding the right settings. Especially be aware of shitty £100 welders that may have very erratic wire feed rates.
    • You don't set current, that's controlled by the interaction of voltage and wire feed rate
    • Manual mode is useful for learning, especially if you expect to have to use fully manual welders elsewhere, but sMIG will almost always give better results when available.
  • Other welding modes - Globular and Spray transfer and the requirements for them
    • Describe conventional (dip) transfer, globular transfer and spray transfer
    • Globular transfer is normally undesirable as it's hard to control but it can achieve a deep penetration at the cost of severe splatter and difficult control
    • Globular has a weird sound, a quiet hiss that's broken by a sharp crack a couple of times per second
    • Spray transfer is a very high powered welding technique used for deeply penetrated welds on thick material
    • The EMP235ic can just barely achieve spray transfer when loaded with 0.6mm wire and with a low-CO2 argon blend gas
    • Spray transfer is very quiet in use, just a quiet whisper. It also produces a LOT of UV light so you'll need a darker shade than normal
    • Both globular and spray transfer modes are only suitable for use on horizontal welds, they cannot be used vertically or overhead
  • Problems
    • Set up and demonstrate each of these
      • Erratic weld, globular transfer - too little wire feed
      • Stabbing and poor penetration - too far away from work or too much wire feed
      • Bead sitting on surface - too fast or too little voltage
      • Weld flat and spattered - too much voltage
      • over-penetration - too slow or too much voltage
      • blowing holes in material - MUCH too much voltage
      • Lots of sparks and brown/porous weld - not enough gas or too far away
  • Using tip-dip
    • The dip is to keep the tip clean, it tends to prevent spatter from sticking to the nozzle
    • The dip is waxy and has to be applied while the tip is hot so you do a bit of welding first, then dunk the tip into the dip and shake off excess
    • Only a thin coating is needed and you don't have to reapply too often, every 10-20 minutes of arc time is fine
    • Spatter can just be rubbed off with a gloves finger as the spatter will not stick
  • Using anti-spatter spray
    • The spray is to protect your work if it needs to be very clean and you can't easily clean it other ways
    • The spray is applied to the work before you start and prevents the spatter from sticking to it.
    • You can weld through the sprayed on coating so long as you don't apply it too heavily
    • But if your welds are structural or otherwise sensitive to contamination, don't use it
  • Controlling weld distortion
    • Metal pulls towards the heat source when it cools and so it pulls in the direction of travel
    • You CANNOT prevent distortion, but you can control it.
    • Extensive tacking and clamping will help reduce it a bit.
      • Tack a lot, correcting distortion as you go
    • Pre-compensation can help
    • Bridge blocks on the back of a weld can restrict it a lot
    • Order of welds within a joint can be used to help cancel out distortion.
      • Consider the directions of travel, that can provide a degree of compensation.
      • Subsequent welds on the same joint have diminishing effects on distortion because the other welds restrain it
      • Standard sequence for T-joint (alternating directions on opposite sides) and mitered corners. (outside, sides from inside to outside, inside in opposite direction)
  • Working with thin (1mm) and thick (5mm) materials
    • For thinner materials heat control is vital, it's easy to heat the work up enough to cause massive distortion
      • As with all welding good tacking technique can limit this
      • Welding only in very short bursts
      • Building welds up entirely from tacks (on both sides when possible) is an effective option
      • Very high risk of blow-through if you try to seam weld something
      • Changing to a thinner wire will help, if your wire is thinner than your material it's easier to control
      • sMIG helps enormously here, far easier than manual, but make sure you train it properly first
    • For thicker materials the challenge is usually getting enough heat into the material
      • For materials up to 5mm or so then single-pass welding is possible but relatively high power levels will be needed
      • The difficult part is getting enough heat into the work to allow the bead to penetrate fully, without dropping out the bottom
      • Thicker wire will help here by allowing you to add more material to the weld pool at a higher rate
      • A wide weave will be needed in order to make sure the puddle melts into both sides correctly without causing under-cut
        • Undercuts are normally caused by too long an arc, too much power, or failing to pause at the edges of the weave
      • An ideal weld will fill the gap and protrude from the surface by 0-3mm, without any sunken areas or under-cuts
    • Multi-pass welding
      • For very thick materials (6mm+) is is likely that this welder will struggle to achieve an acceptable single-pass weld, so multiple passes will be needed
      • Multi-pass welding can be done from one or both sides depending on access. Distortion control will be very much easier if it can be done from both sides
      • Bridge blocks are normally used on multi-pass welds
      • The first pass (called the root) focuses on fully closing the gap at the bottom of the weld with complete penetration, and without causing too much distortion
      • Welds must be cleaned (normally with wire wheel) in between passes
      • Subsequent passes (called fill) are made with a normal welding technique to fill up the grove to just below surface. Alternating sides and directions will help reduce distortion
      • Final pass(s) (called the cap) are made with a much wider than normal weave to finish off the surface and to leave it protruding 0-3mm as for other welds.
    • Very thick materials (8mm+)
      • Standard short-circuit transfer MIG is not recommended on materials >8mm thick
      • It will be very hard to get enough heat into the work to achieve full fusion
      • Spray transfer is recommended, although globular transfer might help
  • Lap joints of dissimilar thickness and dealing with burn-back issues
  • Welding hardening steels
    • Attempting to weld hardened or heat-hardenable steels by conventional approaches will usually result in cracking
    • Consider what wire material you want to use, given the strength of joint you need.
      • Aluminium is the very softest wire, but can only be used on aluminium or titanium
      • Bronze is the still quite soft and the most compliant wire usable on steel, it's very unlikely to result in cracking
      • Stainless steel is harder and stronger but does carry more risk of cracks and needs more care
      • Using a hardenable wire gives the strongest result but has the highest risk of cracking
    • Differential heating and fast cooling causes the trouble
      • If the steel is hardenable then it WILL harden along the edges of the weld
      • Hardening steels normally contract and pull away from the weld resulting in high tensile and sheer stresses
      • Hardened steels are brittle and easily cracked by tensile stress
      • Most of the trouble occurs because the heat-affected zone around the weld is small and cools very rapidly while the bulk of the material remains unaffected.
    • Heat control and management will be needed to prevent cracking
      • Parts can (and usually should) be pre-heated because having the bulk material hot will mean the weld bead cools more slowly
      • Pre-heat temperature is a difficult balance, you'll need to research the metal you're welding and work out if there are any temperature bands that shouldn't be used. If you can't get detailed guidance then temperatures in the range of 250C-400C are normally good. Higher temperatures make the metal harder to handle and increase oxidization but reduce thermal stresses.
      • Work out your clamping arrangements and how you're going to have to move the work around before you start pre-heating, you cannot use clamping magnets because at these temperatures the magnets will be permanently degraded.
      • For small work the materials oven may help, for larger workpieces then the blowtorches can be used.
      • Post-heating is used to try to prevent the weld bead from becoming over-hardened
      • This can take the form of simply wrapping the work in insulation to slow it's cooling, or using the blowtorch or oven.
      • Cooling times will vary with weld size, for large welds several hours may be needed
    • Post-annealing can help if it's done very soon after welding, before the metal has cooled to room temperature
      • Heating the metal up to annealing point and cooling very slowly can be very effective in relieving stresses in the metal
      • But be aware it may change the bulk properties of the workpeice
    • Weld peening can help in difficult situations
  • Welding mild steel in position 3
  • Changing the gas bottle
  • Changing wire, torches and liners, proper setting of wire feed and tension

Optional level 2 modules

Optional modules that can be included in level 2 induction at additional cost to inductee owing to expensive materials needed

  • Welding with Aluminium, using suitable gasses. Costs £15 extra
  • Welding Stainless Steel, using suitable gasses. Costs £15 extra
  • MIG brazing, which allows joining materials with less heat and distortion, and also works on some materials that can't easily be welded like cast iron and tool steels. Costs £30 extra
  • Hard-facing, adding a very hard wear-resistant surface coating to materials using the welder. Costs £30 extra

MMA (Stick welding) Induction

This induction in intended to cover the basics of how to use the MIG welder in MMA (stick welding) mode, it covers basic safety information and how to use the welder effectively on mild steel in positions 1G and 2G/F. It is strongly recommended that people undertake MIG induction and practice it thoroughly before attempting stick welding, that said you can start welding straight away with stick but it's likely to take considerably longer to develop the required skill to use it effectively. People undertaking stick welding induction need to have overalls or other non-flammable clothing that covers all exposed skin except for head and hands. Wear stout shoes or boots, no open shoes allowed. If you have any metal you'd like to practice on then please bring it with you so long as it's plain steel with no galvanized coating or paint but if you don't have any then we usually have suitable scrap around to practice on. There is a charge of £10 for the induction to cover materials and a bit more if you spend some time practicing afterwards which is strongly recommended. The needed materials are usually kept in stock but if we've run out it will take several days to get more. This induction is estimated to take 1-2 hours.

Topic Detailed contents Rationale
Types of welding available
  • MMA - Fast, thick, dirty, good outdoors, medium-high skilled
  • MIG - Fast, medium thickness, relatively clean, low-skill requirement
  • TIG - Slow, Neat, special materials, super-clean, high-skilled
  • Gas - Most similar to TIG but for safety reasons we won't be doing this at rLab
  • Forge - V.V.Slow, good for big flat welds, high-skilled
  • Spot - Tiny spot welds for joining plate, low-skilled
Which technique to use for which weld
How it works
  • Machine strikes an arc between the work and a consumable electrode, melting a pool of metal
  • The electrode melts and is propelled by the arc across the gap into the pool
  • The flux coating on the rod breaks down, emitting inert gas to protect the weld from air and forming a coating of slag over the hot metal to further shield it
  • Earth clamp provides return path
Basic process details
Safety
  • Fire hazard
    • Metal sparks and radiant heat/light
    • Clear area of flammable materials, be aware of solvents and vapors
    • Having fire extinguishers handy and what types are suitable
  • Arc-eye hazard to you and people around you
    • Using an auto-darkening welding mask
    • Suitable settings on mask (9-11, 12 maybe - start at 10 and adjust)
    • Shouting "Eyes" if there are other people around
  • PPE - Overalls, stout shoes, thick leather gloves, mask, dust protection when needed, Cover all exposed skin or you'll regret it!
  • Care with Galvanized steel, risk of metal-fume-fever
  • Gas safety
    • Enclosed spaces, the gasses produced during welding are irritant and asphyxiant.
    • Fumes are nasty, use dust masks or respirators
  • Electrical Safety
    • The voltage is low, but you still don't want to touch it
    • Mind where you put the rod, it's always live and will arc to anything earthed, eject the rod when putting down the stinger
    • Power is controlled from the base unit
    • NO RINGS, NO WATCHES!!
    • Users with implanted medical devices should seek doctor's approval before welding, it's not usually a problem, but please do check
    • The welder plugs into a 16A socket, there is a 16A trailing socket on the pillar, it's fed from the bandsaw power point
    • If the bandsaw is used at the same time it may trip the breaker
    • Use only suitably rated industrial extension leads, they're in the desk drawer B1B
    • Extension leads are a trip hazard, warn people
    • If something does go wrong, shut off power before anything else
Using the equipment without harming self or others
Preparing to weld
  • Check metals are suitable
    • Mild steel only at level 1, Stainless, tools steels and aluminium are possible but we're not covering them today.
    • Beware of galvanized steel
    • Beware of lead-bearing and copper-bearing paints
  • Check the rods are suitable for the material. There are a wide variety of rods available
    • 6013 are a common type and considered "universal" they have a heavy flux and cut through grease and dirt well
    • 7018 Are more common in america, give a stronger weld but have less flux so they need cleaner material
    • There are dozens of other types, if in doubt check online recommendations
    • Make sure the electrode size is suitable for the work
    • Rods must be kept dry, all rods are moisture sensitive but some more so than others
      • Damp rods will form shitty welds and tend to result in slag entrapment and worm holes
    • Baking rods if they're not brand new
    • Keeping them in a rod oven if you get serious about MMA welding.
  • General angle grinder safety
    • Types of disc
    • Inspecting grinder and disc
    • Changing the disc
    • Care of position and cut angle
    • Dust protection, eye protection, gloves
    • DO NOT TWIST in a cut
  • Clean up weld area, a bit, Stick welding can tolerate more dirt and contamination than any other type of welding
  • Clean area for earth clamp
  • Beveling edges to form a path for the bead on butt joints
    • No bevel on thin materials
    • Regular 2/3rds bevel most of the time
    • Beveling from both sides for very thick
Proper preparation is necessary for good welds, cover bevel patterns for other weld types later
Machine Description
  • Parts
    • Base unit is a constant current power source capable of currents between 15A and 240A and an open-circuit voltage of 50V
    • Stinger provides a way to hold the electrode, it can be held in various positions but must always be well-seated into the clamp
    • Earth Clamp
Covering what all the parts are called and setting current
How to actually execute a weld
  • Normal welder settings
    • Navigating the menus and selecting MMA mode
    • Setting suitable current for the electrode size
      • Check online for calculators for current, but absent other guidance, 75-90A for a 2.4mm electrode, 100-140A for a 3.2mm.
    • Changing over the leads and connecting the stinger
  • Proper position of self and electrode, direction of motion
    • Suitable angles to work at (45 degrees is common but much more sometimes helps)
    • Vertical and overhead welds are things that can happen, but not covered at level-1
  • Correct distance (close! almost touching, sometimes actually touching)
  • Tapping flux off the tip if needed to get a clean strike
  • Proper posture for welding
    • Getting comfortable
    • Supporting the cable if needed
    • Chairs if they help
    • Being comfortable and able to move without stretching is critical for good welds
    • Resting your other hand on something to use as a guide
  • Scratch striking, Striking off the work and moving onto it
  • How the pool forms
  • Moving the pool along
  • Keeping the electrode at the nose of the pool
  • Dragging the puddle along behind the rod
  • Using the arc force to keep the slag out of the weld
  • Moving patterns, circles, arc, steady
  • You may need to adjust the shade of your mask to get a clear view
    • Each shade number upwards cuts the light you see in half
    • The temptation will be to look at the arc, but try to focus on the puddle. The puddle is what you need to control and let the machine take care of the arc.
    • Letting weld cool from red heat then chipping off slag. Goggles while chipping. Can sometimes restart through still hot slag, but never through cold slag.

[Demonstrate a good simple weld bead]

Cover the basic technique of establishing and moving a weld bead
Problems

[Deliberately set up and demonstrate each of these faults]

  • Arc too Long - Large arc visible and moving, puddle wide and flat, lots of spatter, undercut risk
  • Angle wrong - Poor visibility, lots of slag trapped in the weld "Worm holes"
  • Too Hot - Weld sounds very different, hissing not "frying bacon"; puddle overly large, concave and spattery; Deep v-pattern; Surrounding material cooked & distorted; Burn-back and undercut issues
  • Too Cold - Globs of metal or a very small bead, weld mounded up convex; not a continuous weld; Weak arc, hard to keep it lit; worm-holes
  • Too Fast - Poor penetration; very narrow; might be discontinuous
  • Too Slow - Overly penetrated; bead rather wide; surrounding metal cooked; worm-holes; might blow right through the work
Recognising faults and knowing how to fix them
Practising a steady bead Inductee practices laying down a straight and steady, well-fused bead on flat stock till competent Getting the basics right
Butt joints
  • Proper grinding and prep
    • Bevels right way up and properly spaced
    • Proper fit-up between parts
    • Option of using backing blocks (Always permanent for MMA)
  • Using holding magnets and clamps
  • Do NOT tack work to the table
  • Tacking to limit distortion, you are GOING to get distortion
    • Straight, back-track and half-split tack welding
    • But don't make the weld sections too short, stopping and starting introduce chance of inclusions
  • Root-weld and multi-pass welding on thick material

[Demonstration and practice till successful]

Executing the most basic weld
Fillet joints
  • Don't need to grind, but parts need to be clean
  • Good fit-up important, will makes things much easier for you
  • Proper position and angles
    • Push angle a little steeper than normal
    • Biased towards the vertical plate
    • Weaving pattern, spending more time on upper plate
  • Stitch and alternating stitch to control distortion
  • Pre-compensation for distortion

[Demonstration and practice till successful]

Second most common weld type
Lap joint
  • Lack of need for grinding but must still be cleaned
  • Treat is as two fillet joints
    • But watch out for heat buildup in the edges
    • Extra care if the sheet is thin to watch for balling up
  • Alternating stitch welds to control distortion
Next joint type
Shutting down and cleaning up
  • MMA welds will always require cleaning with the chipping hammer and wire brush at a minimum
    • Wire brush if you don't care about cosmetics
    • Flap discs will tidy up welds that are good to start with
    • Grinding discs will remove messy welds quickly
  • When you're done shut off the power to the welder and putting the leads away
  • You may need to check the table and/or vice for stuck on spatter and remove it with a file or angle grinder flap disc
  • Sweeping up and putting everything back where it belongs
  • Discuss any projects the inductee is working on to provide pointers
Clean up after yourself and pay what you owe!
Final thoughts
  • This has only been an extremely brief over-view of Stick welding
  • Do not expect your joints to be structurally sound or pretty until you have practiced for many hours
  • If you want to weld aluminium or magnesium alloys, Stainless Steel, Brazing or other techniques then you can look at TIG level 2 or MIG level-2 inductions although it's not compulsory to do level-2 inductions if you've already done the relevant level-1 inductions and if you think you can manage these techniques without further help
  • If you want further tuition then some members of rLab are willing to provide this, but they may charge for it.
Closing comments