Bear with me guys. Tig Questions

admin

First let me say I am no welder. But I want to learn. I recently purchased a Miller Max Star DC Tig machine to fabricate a railings for my sailboat. I'm using 1" 316 stainless tubing, and notching the ends and welding the saddle. I think you're supposed to be able to get a puddle going at the seam of the tubes and fuse them with little or no filler material. I've done this a few times, mostly by accident, and cant reproduce the result consistantly. Also after joining the tubes I will need to polish the joint back to a mirror finish. Can anybody give me a little advice (please - no flames, I know I need to seek the advice of an experienced TIG welder, that's what I think I'm doing now.Thanks in advance for your help.
Reply:In Sunny San Diego where I have built my Kingdom and encourage others to build their's to pass to their children, I would try to get in touch with a TIG welder person that can show you the steps you want to learn to achieve your goals of TIG Welding.It very easy to learn this process and with a little practice with a Tig Person you will become a wiser King in the Welding world.Then buy a Pony for your kids.Last edited by MetalSculptor; 03-26-2006 at 05:08 PM.
Reply:Originally Posted by MetalSculptorIn Sunny San Diego where I have built my Kingdom and encourage others to build their's to pass to their children, I would try to get in touch with a TIG welder person that can show you the steps you want to learn to achieve your goals of TIG Welding.It very easy to learn this process and with a little practice with make you a wiser King.Then buy a Pony for your kids.
Reply:TxRedneckI agree with TxRedneck, getting you to the TIG level of happiness will make you a better person and you will ad value to planet earth and you will have bonded the metal correctly with and good finish
Reply:I am having a really hard time biting my tongue here guys! It gets old when ANYONE repeatedly doles out their "preachings" of any denomination or belief with little or no regard for the audience's desire to hear what that person is saying.
Reply:Thanks for the info so far TX. My rig has a foot pedal and the amperage is goes up to 150. Using pure argon set at 20lbs per the guy at the shop where I bought the thing. I've been expirimenting with various different size electrodes that came with the machine. Not sure which is better, smaller or larger. Also I have an autodarkening hood and I have a little trouble seeing the puddle at times, even set at the lightest shade. As often as not I burn through the tubing and getting both sides of the joint to puddle consistently and run togeter is giving me a hard time. Both sides will get molten and draw back from each other.  Don't know the exact wall thickness of the scrap I'm using to practice with but it is the type you would find in a stainless bow rail on a large boat. I don't have a HF capability with this machine and it starts by touching the electrode to the work and lifting. Any other comments, tips on setup, technique?Thanks again.
Reply:haddison,I think you will find that one very important factor in fusion welding thin stainless steel without adding filler (called autogeneous welding) is too have really perfect joint fit-up.Where there are gaps in the joint, you will have trouble getting the weld to bridge the gap, surface tension will tend to ball up the weld puddle on each side of the joint, leaving you with a bigger melted gap in the joint.In addition to getting a tight fitup between the tubes, it will help the keep the tube ends square, I mean don't bevel or chamfer the tube ends.Tungsten size:  0.040 15-80 amps, 1/16" 70-150 amps DCEN
Reply:Thanks Pulser, just the kind of direction I was looking for. I will take your tips and I will continue to practice until I get it down. Hoyt
Reply:Another thing that you might be missing is the torch movement.  When fusion welding, I have found that a quick circular motion works really well....like drawing a walking spiral of overlapping circles along the joint, maybe 2-3 times the width of the electrode.  Once the material starts to flow, you need to get moving or burn-through is coming soon.  On thin stuff, you don't need much more than a tiny liquid puddle that is dancing on the surface.  Once that puddle starts, you are constantly moving it around and forward.  I am probably stating the obvious, but heck...it might be only a tiny thing you are missing.Smithboy...if it ain't broke, you ain't tryin'.
Reply:i've read this whole thread and the only thing i can type is a sharp tungeston is a happy tungestionno contamination ...zap!
Reply:i use a lot of 1/16" rod not as much buildup for the thin stuff, but do use some 3/32
Reply:OK guys, newbie here has just finished his first halfway decent practice weld. I hope to get better but would be satisfied with what I just did if I can reproduce it with any consistancy.  Pulser, your adivce was spot on regarding the precise fit-up. Absolutely essential, and a challenge with my rudimentary equipment consisting of a notching jig from Harbor Freight which uses a bi-metal hole saw that makes a pretty ugly cut. I cleaned it up with a one-inch round stone chucked up in a high speed rotary tool which worked pretty well as I am welding 1 inch tube. After much experimentation a found that top amperage set up at 50 amps and foot pedal control allows me to get both sides of the joint flowing together and them moving slowly around the tube watching to see the sides flow together. 1/16 tungsten 2% thoriated seems to be the right electrode working it in a little circular motion (thanks Smithboy) and keepin it sharp for a nice neat arc cone (gracias' Zapster).Prop-doc, I didn't get your post until just now but I must have anticipated your advice. Thanks to you too. Oh, and MetalSculptor, blow it out your kindom's as..............Thanks again guys.Hoyt
Reply:Hell, I forgot TXRedneck who started me off. Thanks TX.
Reply:np.....IF it Catches...Let it Burn
Reply:Originally Posted by haddisonThanks for the info so far TX. My rig has a foot pedal and the amperage is goes up to 150. Using pure argon set at 20lbs per the guy at the shop where I bought the thing. I've been expirimenting with various different size electrodes that came with the machine. Not sure which is better, smaller or larger. Also I have an autodarkening hood and I have a little trouble seeing the puddle at times, even set at the lightest shade. As often as not I burn through the tubing and getting both sides of the joint to puddle consistently and run togeter is giving me a hard time. Both sides will get molten and draw back from each other.  Don't know the exact wall thickness of the scrap I'm using to practice with but it is the type you would find in a stainless bow rail on a large boat. I don't have a HF capability with this machine and it starts by touching the electrode to the work and lifting. Any other comments, tips on setup, technique?Thanks again.
Reply:something nobody else   caught. you don't use "20 pounds of gas' pressure". it might be 20 cubic feet per hour . or some other value in "CFH". you set flow rate - (volume) ,  not presure , although ,at Kaiser steel fab shop, i did see MULTIPLE operators using a "home made " (inshop) system , where a pressure reg. was feeding a manifold that several guys using fluxcore&gas  were using (lincoln's  outershield. )
Reply:First thing's first, it's all about fit up with the thin stainless. If you get that done right it's 95% of the job done     Now the welding, throw that foot pedal away, it's just getting in the road   Set your heat, once it's set there's no need to change it.   Try and get one of the bigger gas lenses with maybe a size 10 to 12 cup and set the gas flow to 25 litres, the high gas flow is what keeps the weld clean and shiny on the outside.  If you can it helps a lot to pruge the inside as well. Get a nice sharp 2.4mm tungsten and set yourself with heaps of pushing angle, then light up and wait. What your waiting for is in the middle of the weld pool, your waiting for a wee black thing to start spinning. Once it starts it's time to start moving the torch. If your to slow the weld will drop, so go faster. The main thing to watch is that wee black spinning thing     For heat I'd be running around  58-68 amps, pure argon at 25litres, 2.4mm tungsten and a shade 9 green lense. Not an auto darken either as their not clear enough for this kind of work.Good luckStephen
Reply:Originally Posted by Rockskihmm how thick is your rail? id crank it (personally) and yea sugar on the inside is bad, so... is it possible to splice off your argon line and put a dam on the inside and fill your rail with argon (assuming is round)? just as a precautionary measure, for making it shine like a new rail, id take a flapperdist to grind it down and mayby a sanding disk afterwards to make it all smooth.... i dunno, just venturing a guess for ya
Reply:fusing stainless is really what got me started in getting my gov.certs...i used to make cages that cameras went into and were dragged on the bottom of the ocean to get "terrain" pics (all 308)we just fused the stainless together and used filler when really needed...stainless is good to learn on ...zap!
Reply:Originally Posted by zapsterfusing stainless is really what got me started in getting my gov.certs...i used to make cages that cameras went into and were dragged on the bottom of the ocean to get "terrain" pics (all 308)
Reply:nothing a little scotch brite (brown) pads on a buffer wheel would'nt take care of  ...zap!
Reply:try 10cfm or less on the argon. test on scrap. if you don't have enough flow it will be very apparant. If you can't see it you can't weld it. Use some type of light shined directly on your area to be welded, lamp, trouble light, ect. adjust the sensitivity on your hood down to compensate.The spot light thing works well for MIG also.The mirror finish your looking for can be had. Use a dremel tool with a felt polishing wheel and black or white jewelers rouge. This is a metal polishing compound. Find it at your local jeweler or industrial supply house.
Reply:Originally Posted by alan waterstry 10cfm or less on the argon. test on scrap. if you don't have enough flow it will be very apparant.