Advice on welding steel tube

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Hey guys!  I'm new to TIG.  Been doing MIG for years.  Trying to practice TIG welding steel tube because I want to TIG weld a roll bar in my budget build race car.  Already got an 8 point roll bar kit from a local builder.  It's 1-3/4" mild steel 0.130" wall tube.  I'm practicing on some scraps of the material and I can lay down a straight surface bead no problem.  Roll bars are all fillet welds and apparently I suck at them.  Trying to figure out what I am doing wrong?I have a Miller Syncrowave 200 set at 130 A and using a pedal.  I'm not going that hard on the pedal, about 50-75%.  The filler rod seems to just glob on top of the metal instead of melting and flowing into the puddle on the fillet weld.  I'm 99% sure it's something I'm doing wrong because a surface weld turns out just fine..  Here are a few pics:Pic for tungsten depth.  Need to dress this one dipped it a time or two.ER70s-2 filler rod3 welds on bottom of pic were trying to weld from bottom to top.Weld above that is my surface weld which I don't think is horrible for a beginner.The fillet welds at the top of pic are all the intersecting joints and they look like garbage.Any thoughts?
Reply:too cold..arc length too long..too much stickout for what you are doingLast edited by weldbead; 08-20-2013 at 01:33 AM.
Reply:Stick out might be okay if a gas lens, not near enough heat and maybe to much arc length, turn it up to at least 150 if not 175 and don't be afraid to floor it to get a puddle going.Syncrowave 180 SDMillermatic 250XSnap On MW 120 Econopac 50Victor O/A with some Smith Attachments 30 X 50 shop with a 400 Amps
Reply:the torch angle is likely too much---if it is not about 15° from the perpendicular to the tube surface, then the arc is gonna end up mostly aimed at the filler rod and not the surface of the tube, hence the filler balling up and dropping onto the work piece.  This is why your surface weld (which is not following any curvature at all) is ok, but as soon as you try to go around the circumference of the tube (in the welds going up in the picture), the arc ends up not being pointed to the center of the tube, generally speaking.Perhaps this might help.  The orange is the "orientation" of the tungsten.  The tangent line is the one that "rotates" around the tube.  If you maintain that 105° angle from the tungsten to the tangent, it is the same as staying 15° from the perpendicular.  To maintain that angle relationship, you need to rotate the torch a tiny amount with each and every puddle-dip movement.Last edited by Oscar; 08-20-2013 at 03:18 AM. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:There seem to be a lot of people who get GTAW for a roll cage and dive right in!  Thankfully you've recognized the need for improvement.  I passed up a great deal on an old Abarth years ago because there was a miserably done roll cage with what appeared to be OAW welds.  It was scary!  You need a lot of time with your welder.  Your 'surface bead' is by no means acceptable and with proper practice and instruction you should be able to get results you're proud of and confident in trusting.  Practice on flat plate until you can run a straight and consistent bead.  Start without using the filler rod and work on controlling the weld puddle.  When you are comfortable with that move on to adding filler rod.  When you are putting down good beads move on to welding pieces together flat.  Do bend tests until they consistently pass.  Then when you can do that without thinking about it, move on to tubing.  A lot of hand eye coordination can be worked on with the welder off.  Work on keeping your torch the correct distance from the surface and at the correct angle.  Practice feeding the filler rod this way too.  You have your work cut out for you!  Good luck.
Reply:Don't be afraid to work the pedal a bit harder, at 130 amps you probably ought to have it floored, or at least close to it. Secondly, use a thinner filler rod. 1/16" will probably be the easiest for you to use, you might try .045" too. The thinner filler will flow into the weld much nicer.Give me fuel, give me fire, give me that which I desire.
Reply:Sorry to burst your bubble, but you probably should picka different first project.  Improper proceedure on that could end your life.  Maybe someone here can help you on this one for not too much and you can learn from them. I just wouldn't be doing critical tubing work as my first project.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:Originally Posted by pedaldudeYou need a lot of time with your welder.  Your 'surface bead' is by no means acceptable and with proper practice and instruction you should be able to get results you're proud of and confident in trusting.  Practice on flat plate until you can run a straight and consistent bead.  Start without using the filler rod and work on controlling the weld puddle.  When you are comfortable with that move on to adding filler rod.  When you are putting down good beads move on to welding pieces together flat.  Do bend tests until they consistently pass.  Then when you can do that without thinking about it, move on to tubing.  A lot of hand eye coordination can be worked on with the welder off.  Work on keeping your torch the correct distance from the surface and at the correct angle.  Practice feeding the filler rod this way too.  You have your work cut out for you!  Good luck.
Reply:Wow, thank you for the fast replies!  You all have provided great suggestions to improve my welds and solve the trouble I am having.  I will try them out tonight.To answer the question about, why tube for a first project? Well, the only welding I really do is automotive related.  Mostly Mustangs. Usually custom exhaust or sub-frame connector installation.  All of this can be done with MIG which is what I have experience in.  I have been wanting to learn TIG for years, so I finally got a decent machine and got a basic crash course from a friend of a friend (certified welder) on how to get started.  I don't want to call this guy every time I have a problem, so I have been watching YouTube and finally came here.  My TIG projects will probably be limited to roll bars/cages, and aluminum intercooler piping.  Therefore, I need to get good at tube because that is pretty much most of what you TIG for automotive applications.I actually opted to do mild steel with the first roll bar because Chromoly, while more desirable, is more sensitive to heat control and the joint can get brittle much easier.Again, thank you so much for taking the time to share your knowledge.  I will post up with my progress.MattMiller Syncrowave 200Lincoln SP135T
Reply:for your LIFES SAKE please don't weld that roll bar now. Don't take offense to this but you need a lot of practice. Hey I know what its like 4 years ago I never held a tig torch. I found a community colledge that would let me learn tig only, spent 6 months there bought a Dynasty and put myself in the poor house buying rod and welding everything at work that wasn't nailed down. It was a year and a half before I built my first roll bar. What I did was buy a good hole saw tubing notcher and 20' of 1 3/4" DOM. I used a chop saw and made 3" coupons of every angle the notcher would do and practiced. The hard part comes when you have a joint and a buddy has to hold a mirror so you can see to weld it and figure out how to get it done. Stick with it you will get it and when you do you will be a better person for it because no one can take that knowledge away from you. Best of luck. I use 2% thoriated on everything except aluminum 2% lanthanated. Remember shortest stick out you can for weld. I use a#9 torch and a gas lense with biggest cup for everything. I have a 17 for some aluminum stuff. With a gas lense on some of the severe joints you can push stick out with a little more gas flow.If you have more questions please PM me I would be more than happy to help.Last edited by tig dummy; 08-21-2013 at 10:33 PM.
Reply:Originally Posted by tig dummyfor your LIFES SAKE please don't weld that roll bar now.
Reply:Originally Posted by MikeGyvercrap welds on a rollbar won't kill you,
Reply:Originally Posted by DSWWell they might if the top bar simply falls off and hits you on the head. Considering some of the welds I've seen people do on these things I'm amazed that doesn't happen more often...
Reply:why don't you mig it? a good mig weld is just as good as a tig one at least in this case, then take your time and learn Tig--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:Originally Posted by MikeGyverlol that's a little dramatic don't you think? crap welds on a rollbar won't kill you, it's crashing the car that will.
Reply:Originally Posted by PrimetimeI have to agree here. It's not like he's building an entirely new tube frame chassis, it's a supplement to an existing frame that has plenty of strength in itself. I'm not condoning bad welds, and he definitely needs practice before attempting this project, but let's not get too carried away  IMO
Reply:Here's a site that was posted on Millers site . It may help.http://www.mig-welding.co.uk/tig-tutorial.htm
Reply:Thanks for the suggestions guys! I've practiced a bit more and taking your suggestions.  Minding my torch angle and raising my amperage solved most of my problem.  I became more aggressive with the pedal and started varying my amperage a bit more depending on what the weld was doing.  1/16" ER70S-6 filler also was easier to work with, although it gets used up quick.All I need now is more practice to be comfortable.  Like I said I have been doing this for years and just because I'm not a TIG pro doesn't mean I don't know a good weld is.  Obviously I know I'm not doing good welds now, so the few of you need not worry.  I agree there is some nasty **** out there.  If you search YouTube for roll cage welding there are some hill rods welding a cage in a desoto and the mig welds they do look like garbage. LOLMattMiller Syncrowave 200Lincoln SP135T