2" sch 10 SS - help on the cap

admin

looking for some help on capping 2" sch 10 SS.i can not get the cap to come out with color, it always turns out dark gray. is it possible to weld the cap on sch 10 SS without it becoming gray?i've tried letting the coupon cool to ambient temp before capping, and had no luck. tried only welding quarters, no luck.  low heat and high heat, no luck. tried a bigger cup (#8) and that also did not work. tried 3/32 and 1/8 wire and that made no difference.not really sure what else to do. any ideas? thanks for your time.ryan
Reply:0.109" wall stainless? What amperage have you used? 1/8" wire is too big and 3/32" is on the edge of too big, try 1/16" around 85-95 amps. A #6 cup or larger should get good color, keep the tungsten stickout as short as you can and keep the arc length as short as you can. Don't stay in one spot too long, when you see the puddle flow where you want it, move. Any extra time is just overheating the steel. Too high amperage or too low amperage will cause trouble with overheating stainless, you need to find the "Correct" amperage.Post some pictures if you can.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:smallest wire i have at the hall is 3/32, i'll get some pics tomorrow.should i free-hand the cap? i usually walk the cup on everything. thanks for the help.
Reply:I would freehand anything that size, but that's just me. Some guys lay the torch back really far while WTC, causes the weld to lose shielding faster than if you held the torch closer to 90deg to the tube. If that's what you are doing then freehanding could get you some better color because of the shielding. Are you sure you are keeping a fast enough travel speed while WTC?Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:yea i'm moving pretty quickly. i'll try some of your tips out tomorrow and report back with some picsthanks again
Reply:1/8 or 3/32 wire, walk the cup, cool the base metal to touch with bare hand.IMHO ( and experience.......... I have welded thousands of these in my distant past...), a large gas lens with a large cup opening is required to get optimum color............. along with a very high argon flow rate- much higher than you might use with carbon steel.Are you using a gas lens ?
Reply:this is what the entire coupon looks like. yea i know, its terrible.....  i let this cool down to ambient temp before starting. i used 1/8 tungsten, 3/32 wire @ 85 amps #8 cup with a gas lens. do you guys wait in between passes on the cap? for example, do you weld one half then wait for it to cool and weld the other half?weldertom - what size cup do you recommend? flow rate?
Reply:It doesn't look bad. You can see just a little color where you had a restart, after that it stayed too hot too long. You can see at the start of the bead it was a little colder then got hotter (from the ripples in the weld). I think you might be welding a little slower than you think. You can try pushing a little more filler in to help cool the weld some. Or it needs a few more amps. Or a few less. Its close to where you want to be anyway, just need some fine tuning. What was your CFH?Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Read this, it may give you a few pointers. http://www.millerwelds.com/resources...t-I-do-at-work
Reply:squirmy - usually 20-25. cranked it up to 40 to see if it made a difference and it did not.  ill try picking up the pace a little bit more.showdog - i read you freehand on the fill and cap. how are you doing this "in-postion"? specifically the bottom of 5g and 6g? are you switching hands?one more question for you guys. without a pedal, whats the best way to break the arc as you're coming to the end of the weld?thanks for the input gents. hopefully i can make some progress tomorrow, might have to give the freehand technique a shot.
Reply:Freehand while under the pipe is just like any other overhead freehand. Get under it and hold your arms up  To break the arc, you need to speed up so that the puddle "dries" up (gets smaller) when its small enough you have to snap out to break the arc. There was a post a while ago that I explained it a little better I think, even posted a video by Jody from Weldingtipsandtricks.comAirco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:thanks boss
Reply:Here you go, I'm having trouble with youtube so I can't post just the video. http://weldingweb.com/vbb/showthread.php...ner&highlight=Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Figure out a way to travel way faster. The fine ripples indicate you were moving quite slow.Welding/Fab Pics: www.UtahWeld.com