Basic Tig

[Peter E]

I'm a hobbyist builder. No plans of ever becoming a proffesional. I don't have an own workshop but I can use the great one we got at work as much as I like. I learnt everything I know about frame building from different frame building forums, including how to fillet braze. Unfortunately we recently decided to let go of our Acetylene/oxygen setup so now I'm left with the Tig welding machine. I can join two pieces of metal with it but that's about it. If I am ever to build a frame using Tig I need to practice, a lot. I realize this will be much tougher than learning how to fillet braze but I'll give it a try.

To get me started, could someone point me in the right directions when it comes to Tig settings for welding a frame, diameter of filling rod, cup size etc.

I got plenty of thin walled tubes and sheet metal of mild steel. Is it a bad idea practicing on mild steel. Will it behave differently to 4130?

What would you recommend me to start practice with?

Thanks!

[Rayburn Shaun]

Practice your technique on whatever scrap you have- start with lap joints on flat stock without filler- that's the absolute easiest weld to learn. Mild steel is fine, just practice- over and over again until they're perfect. Figure in rough terms 1 amp per .001" in thickness to start, using DC for steel. Try using 1/8" thick material for starters, not too thick, not too thin- forgiving and easy.

I'm no pro but I'm sure you'll get good advice here.

[Jonathan]

Agree to all of the above. The is no substitute for using lots of argon. One suggestion, if there is a local TIG framebuilder to you, offer to buy two hours of his time. If it costs you $100 an hour you'll save that and more in practice materials later down the road. It sounds expensive, but its way cheaper to develop proper technique early.

[EnginCycles]

Don't worry about settings in the beginning. Turn it on with DC power, crank up the amperage and start welding with whatever is already on the torch. Getting to the point where you can sit at anyones welder and weld is the goal. This is one of those things that is not really bicycle specific. Head over to the Miller forum and read up. Tons of info and all worth reading. Lots of argon is not the answer to anything. You can easily make turbulence with your cup if the torch is not held right and the SCFM is to high. Plenty of bikes are welded with a #5 cup and a 1/8" tungsten and lots with a #10 or #12 and 1/16" and 3/32" tungsten. Again it is not what makes it work. It is all done by the welder (the person not the machine).

The one thing you can do that will be worth while is get a helmet and call it your own. It is something that is worth the $50 to have a personal feel for the task at hand. I can weld with anyones machine but I really prefer my helmet. It is not anything special but it is mine and I like it!

[Jonathan]

Drew, I don't know if you're referring to my lots of argon comment or not but let me clarify. Lots of argon as in practice a lot is what I meant. Not turn up the argon. There is no substitute for practice. The guys like Zank really set the bar.

[fortyfour]

What Drew said and I'll add this...

When I first started out about 20 years ago, I found the torch, pedal and filler too many things to handle all at once. I was too hot, too slow, too shaky, too uncoordinated. So what I recommend for beginners is this (and if you can get someone who knows what they are doing to show you some tips, that helps tremendously):

1. Eliminate the filler. Get a flat sheet of steel (whatever you can dig up or is on hand). Clean it. Get into the habit of being clean right from the get go.
2. Start by laying down beads sans filler, focus on timing, heat control and pace.
3. Once you feel comfortable with this, now focus on angle of the torch and distance of the tungsten tip in relation to the work piece. Lay down beads.
4. Now you've done this for a while, and feel comfortable with all of the above. NOW add in the filler.
5. Focus on pace in relation to bead spacing, timing, and tungsten tip/torch in relation to the work piece. Lay down lines, upon lines of dimes. When you think you've done enough, do more and then some. All on flat sheet.
6. Now you feel comfortable with torch in hand, filler in the other, timing, bead spacing, heat control and pace. Now join two pieces together. Always have your work space clean, clean, clean. Always have your work pieces clean, clean, clean. I cannot stress cleanliness enough with TIG.
7. Make a sh!t ton of joints, angle joints etc. Make as many as you can. Inspect your work, observe what is right and what is not right. Things will begin to fall into place. It's all practice. Things to think about are bead spacing, uniformity of the beads, no undercutting, smooth transitions, minimizing heat input to name a few. If it looks good, it most likely is good. Shiny, blue or gold/straw is what you want. Dull, gray is not what you want. It takes a while to figure all of this out. Just be patient. You're training your body to have muscle memory and control so you can focus on the weld and not where your hand is or what your foot is doing.
8. If you feel comfortable and confident with all of the above, get yourself some .035 wall thickness 4130 and make a bunch of "T's". Practice tacking them and wrapping welds. Practice makes perfect

And like I said above, patience is key. You will begin to notice small gains over time. Just keep at it, practice and know that it just takes a lot of time behind the torch to get good.

Get yourself your own helmet as Drew recommends. Get yourself a good respirator with replaceable particulate filters (3M makes a bunch). Get yourself a nice set of tig welding gloves (Tillman makes some nice ones). Get your own stainless brush. It's all practice, repetition and being comfortable while welding.

Many times with hood up, I will do a dry run of where my hands with torch and filler need to be. How I'm going to walk the cup or where I'm going to perch a finger or wrist off of. This allows you to experiment with different approaches to (for example) tight spots to get into.

Always clip off a clean tip for your filler. Always let your torch finish it's argon post flow before removing it from the weld site. Always clean your work pieces thoroughly before welding. Never throw in the towel.

[edoz]

In the biz we call that "lots of rod". There's no substitute for burning lots of rod.

[edoz]

As far as the filler goes, take a piece home amd practice feeding it through your fingers. Work it all the way to the emd and start over. Then practice pushing a dime across the table. Do it while you read or watch tv or whatever, until it becomes subconcious.

[Jonathan]

In the biz we call that "lots of rod". There's no substitute for burning lots of rod.

Man, I go through argon so much faster but I get that.

[edoz]

Man, I go through argon so much faster but I get that.

Yeah, at my day job the argon is piped in, so I don't even think about it. There is still the occasional helium bottle change, but I empty a lot of rod tubes.

[afwalker]

Peter,
If you're in a fabrication shop, it probably has a good welder.
Try these settings with the .035" tube.
70 amps
1 pps
30 % on time
15% background

Make sure your filler diameter is .045" not .035"
does your argon regulator have a scale for CFH? if so 15-20.
Should get you started. But, as Drew says, it's not so much the settings but the welder. Any good welder will weld anything with any welder.
So, how do you get to be a good welder? Seat time baby! Weld as much tables and jigs and tools and practice joints and then bikes:)
cheers
andy walker
Walker Bicycle Company | | Walker Bicycle Company
Flickr: afwalker's Photostream

[EnginCycles]

The regulator is only because the tank is under pressure (unless liquid argon) the scfh is controlled by the flow meter. All argon tanks will have a flow meter.

Don't use the pulser to learn. It is there to help lower distortion on very thin wall stuff. Learn to make a puddle, see the puddle, move the puddle and feed the puddle. The "look" of a weld you think of is just the puddle cooling as you move.

For the record I weld steel with a minimum of 150 amps and often as high as 175 for disc tabs and stuff along those lines. Only something like a bridge (.020" stay to a .035" bridge) would I go below 100 amps.

[triathloner]

I'm still in the learning stage myself. Another note I didn't see mentioned here is grinding the tungsten. If they have a fancy grinder use that, if not research how to properly grind it on a clean grinding wheel used only for grinding tungsten, It has to remain clean as well. And while you are learning you are going to have to re grind it often as you will tend to get too close or even arc strike the metal and it's going to get distorted.

[edoz]

Don't use the pulser to learn. It is there to help lower distortion on very thin wall stuff. Learn to make a puddle, see the puddle, move the puddle and feed the puddle. The "look" of a weld you think of is just the puddle cooling as you move.

^^This.
Learning with the pulser is a crutch, and you don't need it.
Also, don't bother with the fancy tungsten grinder, learn to do it on a bench grinder. Learn the old fashioned way, don't get yourself in a position where you can't weld if you end up someplace without the special toys.

[Amaro Bikes]

Not much more to say after wise words from Drew, Kris, etc. I would simply add a couple of personal thoughts:
-I don't think is good to read other's settings unless you've tried first some hours on your own, as each machine is different, each person welds differently and if you try to replicate what others do you might end unconfortable or doing things unappropiately for your own machine/speed/technique/tubes/etc. Find your own amps/etc where you feel confortable. The more experience you get, the easier will be for you to decide what settings are ideal for you, and for sure you'll be able to rise amps as your travel speed will be higher, but let your hands take its own time.
-Get yourself a notebook and pencil and write down each time what was your machine settings, tubes, argon flow, rod, etc, and after practicing some hours with each setting, write down your own conclusions, both on the welding quality (bead color, geometry, etc) and your own feeling (too fast, too slow, etc). It might help you out in the beginning to record those figures and even analize afterwards so you can understand the process. Probably, that's the main word: UNDERSTAND.
-Positioning is key, make yourself sure about being well positioned, never start a bead without being 100% sure you'll be ok during the length of it, so double think always what are you about to do. Also is a good help to have a good kevlar right glove, as it allows you to lay the hand over the metal without any heat risk, and fi you have both hands/arms layed over something, your torch/filler control will be much easier. For your left glove, once you've go through enought practice, make sure to use a cotton glove over a standard leather glove, and change this cotton glove every frame or even more, as soon as it's getting some dirt on it, so your rod is always touching clean world.

Good luck and do not get too mad, it takes time, and learning curve is not necessarily progressive or proportional to your hours, TIG is a crazy woman, with her own mood waves... .:o

Cheers

[EnginCycles]

Grind it on a belt sander in the beginning. Belts are cheap and it will work fine. Grinding a tungsten is no different than someone that can shape their own lathe cutting tools and sharpen a drill bit on either a disc or bench grinder. I will put my sharpened tungsten up against anything that came out of a sharpener. I do it on a diamond wheel on a bench grinder.

I will give this advice. Say the shop has a card of tungstens. Take all of them out and sharpen all of them on both ends. When you sit down have all of them handy. No point in having tungsten in a bin and only 1 or 2 ready to go. When learning you probably won't be able to flip the tungsten since you will often have a blob on the end but it is still good practice.

[afwalker]

all the above wisdom has the makings of a sticky/wiki/knowledge thread:)
"TIG is a crazy woman" Nice!
There are so many settings on a tig machine, it's going to take a long time to figure out how they affect the weld.
Basically you need the "Goldilocks Weld". Not too hot, not too cold. You're going to have to make these bad welds to even know what they look like. Plan on burning through thin tubing a lot while you are learning:)
Sure, don't mess with pulsing until you start messing with pulsing. Baby steps, walk before you run. No filler at first. After 200 hours of welding you will get the hang of it!
I just gave some settings to start with, it might work for you. Notice the amps is higher, 2 amps per 0.001" where the usual guideline is 1/thousandth. This is moderated by the limiting of peak time and background amperage.
There are three pulser settings: background amperage %, pulses per second and % on time (peak time).
All this does is try for enough heat to get a good weld, but not too hot to burn through. When Drew says he uses 150-170 amps, it's because he can control all the heat with the pedal, his technique and his zen-master mind control:)
And, he's been doing it well for so long now. Enviable, and as good as it gets.
So have fun messing around, and plan on it being a process and journey.
Oh, and it you decide you'd like to take a bicycle welding class from a mentor, try
Welded Steel Frame Building « Metal Guru
I enjoyed my class there.
cheers
andy walker
Walker Bicycle Company | | Walker Bicycle Company

[EnginCycles]

When Drew says he uses 150-170 amps, it's because he can control all the heat with the pedal, his technique and his zen-master mind control:)
And, he's been doing it well for so long now. Enviable, and as good as it gets.

Walker Bicycle Company | | Walker Bicycle Company

You control the heat with the rod, not the pedal. I have the pedal floored most of the time. Move and feed the puddle with tons of filler. I use lots of rod on a bicycle frame. The reason a puddle would run away from you is because you are not moving and feeding at the correct rate (among many others things but this is most of the reason). There is slight adjustment in the pedal but mostly it is done with the filler.

[afwalker]

Cool, glad I mentioned it even though I perceived it wrong. Cool filler swirled into the puddle would be part of the dance of skill it takes to weld. I'm here to learn, thanks for the tip.
cheers
andy walker

[Rody]

You control the heat with the rod, not the pedal. I have the pedal floored most of the time...There is slight adjustment in the pedal but mostly it is done with the filler.

This is where I choose to have a differing perspective, and why fabrication has so many paths to the same end.

Multiple elements have an effect on the overall creation of the fused joint that can be controlled by the operator; amperage, filler size, filler feed rate, rate of travel, angle of torch, and cleanliness.

The constants, however, are few: composition of the material, wall thickness of the pieces to be joined, heat dissipation properties of the material.

Joining the two takes an approach that is fine tuned by each operator, however the goal is the same; a cleanly welded joint that is solid through the root, creates a gentle transition between the two pieces without removing base material from the parent metal, and a gentle feathering of the filler on the edges.

Ideally, when welding thin walled bicycle tubing, the arc should be placed into the joint so as to create a keyhole, or an equal melting away from the joint's edges, that is then closed with the filler. As you travel forward, melting the material in front of your cooling puddle, your torch angle, distance from the joint, and rate of travel need to maintain consistency insuring you have full penetration, creating a solid/strong joint.

The master welders became so by learning two attributes; visually watching the changing elements of the keyhole/puddle and physically adjusting to maintain ideal conditions. This means that controlling heat input through the pedal, torch angle and distance, feed rate and travel speed, all becoming individual adjustments that factor into a cohesive whole.

The introduction of "pulsed" welding was intended to reduce overall heat input to the material, reducing HAZ and maintaining molecular stability. However, it was quickly adapted to creating a set of machine adjusted parameters that each operator found to be ideal for specific tasks. This is not to take away from the need to control the aforementioned elements, but it greatly reduced the need for on the fly changes, making it more efficient for the pro operator who is tasked with similar jobs frequently.

I have always been of the school of thought that I analyze the material properties I plan to join, set the machine amperage at the maximum I feel will be necessary for changing conditions (moving from varying wall thicknesses) and then use the pedal and individual physical adjustments to best react to the situation. This places the pedal most often in the middle of the travel range allowing for extended comfort and control, as the heat input can be increased or tapered off easily.

To create settings on the machine that mandates the pedal be "floored" for the majority of the pass takes away the ability to react, leaving only elements that have less effect, such as filler rate, to aid control.

Don't get me wrong, I'm not saying that this is wrong, incorrect, or not efficient. Only that it is an adoption of a new philosophy of welding, one that I feel is less controlled by the instincts of the operator.

As a beginner, you need to focus on learning to watch the physical reaction of the base metal and what it means. Examine how it changes with faster travel, more filler, varying torch angle, etc... Only after you achieve an understanding of how YOU affect the material can you then begin to examine settings on a machine that ease the process.

My two cents, for what it's worth.

rody