* 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!
Revision as of 17:03, 4 February 2020
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 for level-2 induction to cover the increased cost of materials and trainer time associated with these more complex uses.
Main level 2 induction
Going into Manual mode on the welder and suitable settings to use
Other welding modes - Globular and Spray transfer and the requirements for them
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
Working with thin (1mm) and thick (5mm) materials
Lap joints of dissimilar thickness and dealing with burn-back issues
Using tip-dip and anti-spatter spray
Welding hardening steels
Welding mild steel in position 3
Practising multi-pass welding
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 £10 extra
Welding Stainless Steel, using suitable gasses. Costs £10 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.