Tools/TIG/induction: Difference between revisions
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{{inductioninfo}}
<div id="level1"></div>
== TIG welder induction (TIG Mode) Level 1 ==
Level 1 induction in intended to cover the basics of how to use the [[Tools/TIG|TIG welder]], it covers basic safety information and how to use the welder effectively on mild and stainless steel in positions 1G and 2G/F
{| class="wikitable"
Line 18 ⟶ 19:
* Forge - V.V.Slow, good for big flat welds, high-skilled
* Spot - Tiny spot welds for joining plate, low-skilled
* Gas - Gas welding is most similar to TIG but we don't have it at rLab for safety reasons
|-
| Safety ||
Line 27 ⟶ 29:
** Using an auto-darkening welding mask
** Suitable settings on mask (9-11, 12 maybe - start at 10 and adjust)
*** Testing visors before use
*** Any setting will save your vision, you're just adjusting for best visibility
** Shouting "Eyes"
* PPE - Overalls, stout shoes, gloves, mask, dust protection when needed, Cover all exposed skin or you'll regret it!
Line 34 ⟶ 38:
** 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 a little after the trigger is released
** NO RINGS, NO WATCHES!!
** If something does go wrong, shut off power before anything else
|-
| Preparing to weld ||
Line 69 ⟶ 79:
** As for MIG/MMA but TIG emits even more UV owing to continuous arc mode
* Gas safety same as MIG
* Electrical Safety same as MIG
|-
| Preparing to weld ||
Line 91 ⟶ 102:
* Machine strikes arc between the work and a non-consumable tungsten electrode, melting a pool of metal
** TIG welding is the most similar welding process to soldering but there's still an important difference. In TIG welding you're melting the base material and allowing it to flow together, not only adding material on top
* Filler wire is added manually while moving the torch forming a weld bead that joins the metals
* Gas shields the weld pool and the tungsten from air exposure
Line 112 ⟶ 124:
* Gas bottle
** Type of gas and why
** Basic safety for the Albee bottles
|| Covering what all the parts are called and do
|-
Line 122 ⟶ 132:
** The weld zone must be immaculately clean
** Cleaning the weld with solvents
*** Acetone is recommended, pure alcohols like IsoPropanol or Methanol will generally work, Meths or white spirit will not.
*** NEVER Chlorinated solvents like brake cleaner (Phosgene risk)
** Remove all solvents and cloths when done because of fire risk
** Avoid even touching the weld zone once it's clean
* Clean area for earth clamp
Line 134 ⟶ 144:
** Types and their suitability
*** 2% Thoriated (Red Tip) - DC Welding on steels only, radiation danger
*** 2% Lanthanated (Blue Tip) - Universal, can be used on all metals and polarities, recommended for normal use
*** 2% Ceriated (Grey Tip) - DC use on thin materials, excellent arc stability at low powers
*** Others are available for special job but these should cover 99.9% of welds
** Selecting a suitable diameter (diameter 50%-100% of work-piece thickness, checking chart on welder)
** Grinding a suitable point, 30 degree point, blunted tip if running higher currents
** Picking a suitable
** All fittings on the torch are hand-tight only, no tools allowed
* Torch
** Picking a gas cup from the table on the welder and fitting it, what the cup numbers mean
** Using a suitable back cap, access and clearance issues, silicone grease is needed
** Setting stick-out
** Power button on torch
*** Option of using pedal control later but for now stick to the button
Line 149 ⟶ 160:
* Welder
** Checking correct polarity, making sure earth lead is connected to work
** Check tightness of connectors, they'll catch fire if they're loose!
** Plug in welder but don't turn on yet. Directly plug in, never use extension leads
* Gas
** Check remaining gas level
** Setting suitable gas flow rate using
** Connecting cylinder▼
▲** Setting suitable gas flow rate using both bottles using the table on the welder, but consider situation of weld
||
Suitable setup and settings for executing the weld
Line 168 ⟶ 177:
** Pulse mode
*** Useful sometimes but details not covered in level-1, leave this turned off
** Purge - Used to clear air from the lines
** Power and overheat lights - Duty cycle, 100%@90A, 60%@115A, 20%@200A but max is about 120A on 13A plug
** Process
Line 178 ⟶ 187:
*** 4T - Press and release to start, press and release to stop, good for long welds but has more parameters to set and harder to use, not covered in level-1
* Parameters set using the middle section. We're using DC (Electrode negative), no pulse, HF-TIG in 2T mode. Back and Forward controls step through the parameters that are relevant to the selected mode
** Using the chart on top of the welder to pick settings
** Do not attempt to reduce settings very much to make things easier. Small current reductions may sometimes be needed but if you try to slow down too much the weld will turn to shit and heat affected zone will be huge because you'll be going so slow. You just have to learn to keep up with proper settings.
** If the chart isn't helping then use the following guidelines. Use all the %age changes that apply to your work, e.g. if you're doing an outside corner on stainless steel then apply both -%10 current for Stainless and -10% current for outside corner for a total of -20% change to current and +45% gas
{| class="wikitable"
|-
! Basic Current & Gas !! 40A/mm of material thickness !! 1L/min per cup number
|-
| Inside corner || +10% current || -20% Gas flow
|-
| Outside Corner || -10% current || +25% Gas flow
|-
| Stainless Steel || -10% Current || +20% Gas flow
|}
** Preflow - Time in seconds, is used to establish coverage of shield gas before the arc is ignited. How much to use will depend a little on what you're doing but 0.5-1.0 seconds is usually reasonable for steel
** Hot Start - This is an extra very short pulse of current used to help establish the arc, this is IN ADDITION to the base current, so you don't need very much, 5A-20A is normal
** Base Current - This is the normal weld current that will be used for the entire weld, check the chart for an initial reasonable setting for your job. Think carefully about this one, it's your biggest factor controlling heat buildup in the weld. If you go too high the weld will overheat, but it'll ALSO overheat if you go too low because you'll have to slow down too much.
** Downslope - This is how long the welder spends backing the current
** Post-Flow - This is how long the gas stays running after the arc has stopped in order to keep the weld and especially the tungsten shielded as they cool down. It will depend on how large your weld is, huge welds might need as much as 15 seconds, a small weld with a small electrode might only need 3 seconds. We'll be using 5 seconds as a middle-of-the-road setting but you might need considerably longer on stainless steel. You must keep the torch pointed at the weld throughout the post-flow period and also note that if you press the trigger again during post-flow the arc will re-ignite instantly!
|| How to set the arc parameters
Line 189 ⟶ 211:
* Overalls are required for UV protection
* We have special TIG gloves that are much lighter and less stiff than normal welding gloves which can be used because TIG doesn't generate very much radiant heat or spatter. These gloves are made of goatskin or pigskin and are specifically reserved for TIG welding and must not be used for anything else
* Welding masks will protect your face and eyes from the UV light
* Depending on the welding current you may want to use shade 9-12 on the welding helmet. All settings will save your vision, you're just adjusting for best visibility. If you're used to MIG/MMA then go one setting darker than you normally would for this current▼
** Test the visor before use
** Change the cover sheets on them if necessary, report it if we're out of properly fitting replacements
▲** Depending on the welding current you may want to use shade 9-12 on the welding helmet. All settings will save your vision, you're just adjusting for best visibility. If you're used to MIG/MMA then go one setting darker than you normally would for this current.
* You may see people online welding without overalls or even without gloves. They can get away with this because of the low-spatter nature of TIG welding. DO NOT DO THIS - They are probably wearing SPF-1000 sunblock and have developed a tolerance over years, they'll still probably wind up getting skin cancer from it! Cover all exposed skin at all times while welding.
|| Using the right PPE for TIG welding
Line 195 ⟶ 220:
| How to actually execute a weld ||
* Proper position of self
** TIG can be used in all standard positions, but over-head is rare and difficult as there's a tendency for the puddle to fall out onto you.
** Holding TIG torch in your dominant hand and the filler rod in the other hand
** Getting a comfortable position, sitting down if possible
Line 202 ⟶ 227:
** TIG requires precise, steady movement, so it's very important to be comfortable and able to move freely while doing it.
* Proper position of torch, direction of motion
** Ideally we'd hold the torch perfectly vertical but if we did that we wouldn't be able to see what we were doing or feed in filler rod, so we normally use a push angle of 10-30 degrees. More perpendicular torch position will usually result in a better weld but consider your movement, access, and vision, angles 45 degrees or more WILL NOT WORK PROPERLY.
** Pull welding with TIG is not a thing, don't try it, but it is sometimes possible to back-track a very short distance (no more than the puddle width) in order to move the puddle around and get full fusion.
** Correct distance of the tip is only 1x-2x the diameter of the electrode you're using, and needs to be maintained very steadily. Maintaining this distance properly is the single most challenging thing about learning to TIG weld and will have the biggest effect on your weld quality
** The tip must never touch the weld or the filler rod, in fact it should never touch anything if you can help it! Even the slightest contact will require you to re-grind the electrode. With Steel this isn't too bad as you'll only loose the small section that touched, with other metals you may wind up having to grind away as much as 10mm of the electrode to restore proper operation.
* How the pool forms under the electrode, angle of the arc and how it directs the pool
* Taking the pool "for a walk"
* Moving patterns, circles, arc, steady, stepped
* TIG welding is nearly silent when done correctly, the proper sound is a very faint hiss or buzz when using DC, and a slightly louder humm or whine when using AC or pulse mode, there should be none of the popping or crackling sound associated with other welding techniques. There should be practically no sparks or spatter, if you're seeing any of them at all, you've not cleaned the work well enough.
* What I'm going to do now is to demonstrate how the TIG welder forms and moves a weld puddle, I won't be adding in any filler rod at all to keep things simple. This is usually called "reflow" welding and is the easiest TIG technique.
* [Demonstrate walking a puddle along a bit of thick material]
Line 228 ⟶ 253:
| Arc too long || Puddle is slow forming, arc sounds/looks like a flame, heat zone very large || Having the arc too far away is causing the voltage to go too high and meaning the heat is spread over too wide an area
|-
| Arc too short || Puddle is tiny, pool rises up to touch electrode || Having the arc too short focuses the heat onto too small an area which will make it hard to join workpeices, the short arc causes the pool to actually dome upwards and move towards the electrode. When the tip touches if it gets stick don't try to break it free, stop, let it cool, take the tungsten out of the torch then snap it off the work
|-
| Angle too steep || Large flame-like arc, elongated puddle, difficulty controlling filler rod || The steep angle causes the arc to spread out sideways and fail to remain directly under the point of the electrode, the heat spreads too far down-weld of the torch changing the puddle shape and the plasma jet tends to melt filler rods before they can get to the pool.
Line 238 ⟶ 263:
| Travel too fast || Gaps/thin spots in bead || Fast movement has pulled the bead forward faster than the welder could melt the material
|}
||
|-
|
|-
| Laying a bead using filler ||
Line 254 ⟶ 279:
* Holding the tip of the filler rod near the puddle so that it's shielded, but not so close it melts
* Dipping the tip of the filler rod into the nose of the puddle and quickly back out again
** Contact with the puddle melts the filler rod, not the arc
* The puddle will rise every time you dip the rod so be careful it doesn't touch the electrode
* May be helpful to use stepped movements on the electrode
Line 260 ⟶ 286:
[Inductee practices laying a filler bead]
|| Laying a bead while using filler
|}
Depending on how things are going and the amount of time available the induction can stop here and allow the inductees to practice welding until they're comfortable with reflow and filler beads. The induction can resume on another day to complete the training on how to actually join metal together. If so the "Shutting down and cleaning up" section below should also be covered.
{| class="wikitable"
|-
! Topic !! Detailed contents !! Rationale
|-
| Butt joints ||
[Coupons used must be 2mm thick steel, thinner makes this too hard for inductions]
* Can be done with (conventional) or without (re-flow) filler
* Proper grinding and prep
Line 277 ⟶ 312:
|-
| Fillet joints ||
[Coupons used must be 2mm thick steel, thinner makes this too hard for inductions]
* Don't need to grind, but parts need to be clean
* Good fit-up essential
Line 291 ⟶ 327:
|-
| Lap joint ||
[Talk about but don't demonstrate this type]
* Lack of need for grinding but must still be cleaned
* Treat it as two fillet joints
Line 309 ⟶ 346:
|-
| Final thoughts ||
* This has only been
* Do not expect your joints to be structurally sound until you have practiced a lot
* If you want to weld aluminium or magnesium alloys, TIG-Braze or other techniques then you're welcome to come back for level-2 induction although it's not at all compulsory if you think you can manage these techniques without
* If you want further tuition then some members of rLab are willing to provide this, but they may charge for it.
|| Closing comments
|}
<div id="level2"></div>
== TIG welder induction (TIG Mode) Level 2 ==
Level 2 TIG induction is intended to allow people to convert from working on steel to
[[Category:inductions]]▼
* Working on and welding aluminium, magnesium, silicon alloys
** Using AC rather than DC and why
*** Using wave-balance
** Different electrode types
** Reduced current handling on AC
*** Must be used on 2T mode
*** How to set the current range on it
*** Practice using it to ramp up and down current
** Balling the tip, not necessary but helpful
** Letting the puddle form then moving
** The puddle is a lot more fluid than on steel
** Care with how you use the filler rod
** Backing down current near edges and as material heats up
** Anti-cratering at the end
* Further develop the skills required for more challenging welding applications such as position 3&4 welds
* TIG brazing
* Use of 4T mode
* Using pulse mode
* Using gas lens system
* Maintaining & Cleaning the torch
* When and how to use back-purge (we don't have any fittings for it)
▲[[Category:inductions]]
|
Latest revision as of 15:34, 9 November 2023
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
TIG welder induction (TIG Mode) Level 1[edit]
Level 1 induction in intended to cover the basics of how to use the TIG welder, it covers basic safety information and how to use the welder effectively on mild and stainless steel in positions 1G and 2G/F. People undertaking TIG 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's no charge specifically for the level 1 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. This induction may takes up to 3 hours depending on skill. Please remember that what you might have seen on youtube/instagram is people showing off their very best welds that may have taken years of practice and multiple attempts to achieve, you will NOT be getting results like that after just an induction. The goal for induction is to be able to use the TIG welding without being a danger to yourself or others, it's not even to achieve structurally sound welds, TIG welding is a high-skilled process and it takes a minimum of hundreds of hours of practice to get photograph-worthy results like that.
For people who've not welded before | For people who can already MIG weld | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For people who've not welded before the full technique and safety briefing is required
|
For people who can already MIG/MMA weld this can be shorter
|
Topic | Detailed contents | Rationale | ||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
How it works |
|
Basic process details | ||||||||||||||||||||||||||||||
Machine Description |
|
Covering what all the parts are called and do | ||||||||||||||||||||||||||||||
Preparing to weld (continued) |
|
Proper preparation is necessary for good welds | ||||||||||||||||||||||||||||||
Setting up the welder |
Start at the tip of the torch and work back....
|
Suitable setup and settings for executing the weld | ||||||||||||||||||||||||||||||
Configuring the welder |
Welder Settings
|
How to set the arc parameters | ||||||||||||||||||||||||||||||
PPE safety |
|
Using the right PPE for TIG welding | ||||||||||||||||||||||||||||||
How to actually execute a weld |
|
Cover the basic technique of establishing and moving a weld bead | ||||||||||||||||||||||||||||||
Problems |
These are some of the problems you might find when welding [Deliberately set up and demonstrate each of these faults]
|
Recognizing faults and knowing how to fix them | ||||||||||||||||||||||||||||||
Practicing a steady bead | Inductee practices moving the puddle on flat stock till competent (may take a lot of time and re-grinding) | Getting the basics right | ||||||||||||||||||||||||||||||
Laying a bead using filler |
[Demonstrate laying a bead along a bit of thick material] [Demonstrate too little and too much filler] [Inductee practices laying a filler bead] |
Laying a bead while using filler |
Depending on how things are going and the amount of time available the induction can stop here and allow the inductees to practice welding until they're comfortable with reflow and filler beads. The induction can resume on another day to complete the training on how to actually join metal together. If so the "Shutting down and cleaning up" section below should also be covered.
Topic | Detailed contents | Rationale |
---|---|---|
Butt joints |
[Coupons used must be 2mm thick steel, thinner makes this too hard for inductions]
[Demonstration and practice till successful] |
Executing the most basic weld |
Fillet joints |
[Coupons used must be 2mm thick steel, thinner makes this too hard for inductions]
[Demonstration and practice till successful] |
Second most common weld type |
Lap joint |
[Talk about but don't demonstrate this type]
|
Next joint type |
Shutting down and cleaning up |
|
Clean up after yourself and pay what you owe! |
Final thoughts |
|
Closing comments |
TIG welder induction (TIG Mode) Level 2[edit]
Level 2 TIG induction is intended to allow people to convert from working on steel to more complex tasks. You must have completed level 1 induction and practiced it to a reasonable level before undertaking level 2. There is a charge of £30 to cover materials, machine charges and trainer time for Level-2 induction, at least a week's notice is required in order to get the necessary materials and the induction is anticipated to take 2-3 hours.
- Working on and welding aluminium, magnesium, silicon alloys
- Using AC rather than DC and why
- Using wave-balance
- Different electrode types
- Reduced current handling on AC
- Connecting the foot peddle
- Must be used on 2T mode
- How to set the current range on it
- Practice using it to ramp up and down current
- Balling the tip, not necessary but helpful
- Letting the puddle form then moving
- The puddle is a lot more fluid than on steel
- Care with how you use the filler rod
- Backing down current near edges and as material heats up
- Anti-cratering at the end
- Using AC rather than DC and why
- Further develop the skills required for more challenging welding applications such as position 3&4 welds
- TIG brazing
- Use of 4T mode
- Using pulse mode
- Using gas lens system
- Maintaining & Cleaning the torch
- When and how to use back-purge (we don't have any fittings for it)