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 £5 for the induction and a bit more if you spend some time practising afterwards which is strongly recommended
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
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 vapours
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"
PPE - Overalls, stout shoes, thick leather gloves, mask, dust protection when needed, Cover all exposed skin or you'll regret it!
Care with Galvanised 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!!
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
Beware of galvanised 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
Bevelling edges to form a path for the bead on butt joints
No bevel on thin materials
Regular 2/3rds bevel most of the time
Bevelling 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
Torch
Shroud
Tip
Trigger
Gas bottle
Types of gas and why
Regulator
Basic gas bottle safety
Earth Clamp
Controls
Gas Flow
Wire Feed
Power
Don't worry about timer mode, it's not very useful and just make sure it's turned off
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 all normal welding modes
Timer off unless you know you need it
Reasonable starting settings for 0.6mm Mild Steel wire
Metal Thickness
Power Setting
Wire feed rate
Note
<1mm
1
2
Very difficult, try TIG instead
1mm
2
3
2-3mm
4
4-5
5mm
6
8
>5mm
6
9
Not recommended! Probably won't work
Proper position of self and torch, direction of motion
Push welding - Normal, safe option
Pull welding - bigger bead, better penetration, lots of grind and risk of inclusion
Vertical and overhead welds
Correct distance
How the pool forms
Dip transfer, globular transfer, spray transfer
Taking the pool "for a walk"
Moving patterns, circles, arc, steady
Proper sound "Frying Bacon"
[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]
Erratic weld, globular transfer - too little wire feed
Stabbing and poor penetration - too much wire feed
Bead sitting on surface - too fast or too little power
Weld flat and spattered - too much power
over-penetration - too slow or too much power
blowing holes in material - MUCH too much power
Lots of sparks and brown/porous weld - not enough gas or too far away
Weld moves around erratically - too much gas or influence from holding magnets
Weld sticks to tip - too close
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 (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-tack 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 essential
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
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
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 compeltely
Care with thick base plates as heat dissipation may cause cold-shuts
Fixing wheels and fittings onto things
Shutting down and cleaning up
MIG welds usually require grinding back with an angle grinder to make them neat
Flap discs will tidy up welds that are good to start with
Grinding discs will remove messy welds quickly
Shutting off and purging the gas before un-hooking the couplings
When you're done shut off the power to the welder
Sweeping up and putting everything back where it belongs
Working out your total weld length and paying for it
Clean up after yourself and pay what you owe!
MIG Welder induction - Level 2
Level 2 induction should cover more advanced uses
Welding mild steel in position 3
Changing wire, torches and liners, proper setting of wire feed and tension