Backpurging stainless exhaust tubing

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Any down n dirty backpurging ideas for stainless exhaust pieces?   Post up pics of your setups!ThermalArc 181i | Lotos WS200
Reply:well the basic premise is simple:  feed argon into one end at a lower height than the other end, without introducing air, to properly displace most if not all of the oxygen inside the tube.  Technically you can accomplish this many ways, from fancy parts and hose fittings, all the way to just using a single open-ended hose stuffed with a rag on one side, and a taped-off end on the other with a few holes poked in it.  You can also use SolarFluxB to prevent sugaring.What exactly is troubling you? 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:Welding stainless tubing without backpurge leaves it looking grey on the outsideThermalArc 181i | Lotos WS200
Reply:Originally Posted by zeus_r6Welding stainless tubing without backpurge leaves it looking grey on the outside
Reply:I'll send along these pics of the set-up I use to keep up on my stainless.  Simple 'y', one hose to torch, the other on a valve controlled lead.  Tape tubing, leave relief hole, crack feeder line for 20-30 seconds, turn feeder down to trickle, weld normally.  It works.  Try it before investing in two flowmeters.
Reply:Why would anyone want to purge exhaust pipe?Headers maybe but exhaust pipe?Waste of time and gas and effort.Ever watch "Overhaulin" or "Fast and Loud" or any of those type shows?Never seen anyone do it on a exhaust system....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I have a friend at work that wants to weld his own stainles exhaust on a 67 Camaro.I explained the back purging and I think he has decided that it doesn't have to be that pretty...GravelThe difference between theory and practice is that in theory there is no difference.
Reply:Originally Posted by GravelI have a friend at work that wants to weld his own stainles exhaust on a 67 Camaro.I explained the back purging and I think he has decided that it doesn't have to be that pretty...
Reply:i agree with zapster   unless its headers dont bother noone is going to see the color of your welds or care when its under the car aslong as the weld doesnt leak or look like dog crap.
Reply:Its going on a dragbike... Pipe running along the sideThermalArc 181i | Lotos WS200
Reply:Originally Posted by OscarSolarFluxB is rather inexpensive and works well.  Just get some Heet brand water remover (yellow bottle) to mix it with, apply on the inside of the exhaust pipe, and you're good to go!
Reply:Originally Posted by OscarSolarFluxB is rather inexpensive and works well.  Just get some Heet brand water remover (yellow bottle) to mix it with, apply on the inside of the exhaust pipe, and you're good to go!
Reply:I use SolarB weld flux for back shielding stainless often. I mix mine with 99% alcohol.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:How do you apply it?ThermalArc 181i | Lotos WS200
Reply:With a brush.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:I got mine from www.weldingsupply.com in the 1lb can for $38 or so. 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:Originally Posted by zeus_r6Any down n dirty backpurging ideas for stainless exhaust pieces?   Post up pics of your setups!
Reply:I thought the reason you needed to backpurge was because the sugar induces porosity and weakens the weld.
Reply:Originally Posted by turismolover22I thought the reason you needed to backpurge was because the sugar induces porosity and weakens the weld.
Reply:Originally Posted by zeus_r6How do you apply it?
Reply:Originally Posted by snoeproeGoogle SolarB weld flux and have a read.
Reply:Not so important on an exhaust system, but one problem I've found with solar flux is that if you coat your joint, tack it up, and then feather your tacks....after the heat hits the flux a good portion comes off during grinding.  Recommend experimenting with it.
Reply:Originally Posted by OldSparksNot so important on an exhaust system, but one problem I've found with solar flux is that if you coat your joint, tack it up, and then feather your tacks....after the heat hits the flux a good portion comes off during grinding.  Recommend experimenting with it.
Reply:I wouldn't use solar flux. I hate that stuff especially for smaller tubing. Just use argon you'll thank me....Also, you can achieve good color without purging, you need more gas flow or your welds are getting too hot. Try larger gas coverage cups if you are keeping the heat low.Miller Dynasty 200Millermatic 211Instagram?.... find me @ WELD_MEDIC
Reply:Originally Posted by tig_21I wouldn't use solar flux. Ok!I hate that stuff especially for smaller tubing. Just use argon you'll thank me....Thanks!Also, you can achieve good color without purging, you need more gas flow or your welds are getting too hot. Amazin!Try larger gas coverage cups if you are keeping the heat low. Incredible!Originally Posted by shovelon
Reply:Originally Posted by Oscarare you talking about using solarflux to do SS pipe welding where the initial tacks are sometimes ground off?
Reply:Don't bother with the solar flux, just purge it. It's a bike not a 40ft long bus.masking tape off both ends, and each joint you're not welding to seal it, poke some holes in one end and aim it up while you purge the pipe for a few minutes at like 20cfh. Once it's purged you can drop the flow down to 10cfh and move the pipe around however you want while welding it (as long as any gaps are taped up). Best to use a sintered brass air muffler to diffuse the argon flow so it doesnt just mix with the air, but actually stays seperate and purges it out the top. http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40.Last edited by MikeGyver; 03-14-2014 at 08:21 AM.Welding/Fab Pics: www.UtahWeld.com
Reply:Originally Posted by MikeGyverDon't bother with the solar flux, just purge it. It's a bike not a 40ft long bus.masking tape off both ends, and each joint you're not welding to seal it, poke some holes in one end and aim it up while you purge the pipe for a few minutes at like 20cfh. Once it's purged you can drop the flow down to 10cfh and move the pipe around however you want while welding it (as long as any gaps are taped up). Best to use a sintered brass air muffler to diffuse the argon flow so it doesnt just mix with the air, but actually stays seperate and purges it out the top. http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40.
Reply:There is a new stainless rod on the market that is for stainless and creates a flux on the inside so no need to back purge.I think I threw out the magazine on it though.Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:I just welded up some 14g building a muffler...welds are very pretty outside and inside there is barely a spot of sugar...304 stainless. I just set my machine at 120amps 33pps and went to work....used 308l mig wire .030 two strands twisted for filler...salmon colored welds even silver on spots Inside the can. My buddy said I hit 38amps...60° triangle shaped can outside corner welds. No purge. I think youll be fine no purge just be super careful...I used 8 lens with 15cfh 1/16th thor tungMiller Syncrowave 210 w/CK FlexLoc 150  3/6/14ESAB PCM 1125 Plasma CutterAtlas 12x36 LatheACER 9x42 3hp millHarig 612 Surface GrinderDRINK Machine              welding&fabrication
Reply:Originally Posted by chevydylI just welded up some 14g building a muffler...welds are very pretty outside and inside there is barely a spot of sugar...304 stainless. I just set my machine at 120amps 33pps and went to work....used 308l mig wire .030 two strands twisted for filler...salmon colored welds even silver on spots Inside the can. My buddy said I hit 38amps...60° triangle shaped can outside corner welds. No purge. I think youll be fine no purge just be super careful...I used 8 lens with 15cfh 1/16th thor tung
Reply:I have some pics I got to edit them ill post a new thread. Lol my work computers block my image hostMiller Syncrowave 210 w/CK FlexLoc 150  3/6/14ESAB PCM 1125 Plasma CutterAtlas 12x36 LatheACER 9x42 3hp millHarig 612 Surface GrinderDRINK Machine              welding&fabrication
Reply:so here is a shot of the weld i spoke of, i dont have any inside shotsMiller Syncrowave 210 w/CK FlexLoc 150  3/6/14ESAB PCM 1125 Plasma CutterAtlas 12x36 LatheACER 9x42 3hp millHarig 612 Surface GrinderDRINK Machine              welding&fabrication
Reply:This is what I end up with... And it's my first tig weld on stainless exhaust tubing so it does look crappy... Ideas on getting better color? ThermalArc 181i | Lotos WS200
Reply:Originally Posted by zeus_r6This is what I end up with... And it's my first tig weld on stainless exhaust tubing so it does look crappy... Ideas on getting better color?
Reply:I will tell u I use about 3/8 stickout with my setup.Do you have a pedal? If your using the machine in your sig I say good luck...lots of practice. ..my new miller has definitely been a blinder to my actual skill lol. Pulse on thin metal is amazing the pic I showed was only my first stainless joint. The whole thing was 45inches of weld. 5 3in passes per joint. I was in a very comfortable position to slide. The welds are near perfect.. whats your amps? And whats the tubing thickness? 14ga I think is 0749. 1amp per thou =74amps. I used 38 40 topsMiller Syncrowave 210 w/CK FlexLoc 150  3/6/14ESAB PCM 1125 Plasma CutterAtlas 12x36 LatheACER 9x42 3hp millHarig 612 Surface GrinderDRINK Machine              welding&fabrication
Reply:Doesn't look like much prep on that pipe. A little clean up goes a long ways. Not sure I would get too worked up over back purging a bike exhaust. **** most bike builders don't. You just need more practice. Good Luck
Reply:Originally Posted by OldSparksI'll send along these pics of the set-up I use to keep up on my stainless.  Simple 'y', one hose to torch, the other on a valve controlled lead.  Tape tubing, leave relief hole, crack feeder line for 20-30 seconds, turn feeder down to trickle, weld normally.  It works.  Try it before investing in two flowmeters.Attachment 652161Attachment 652171Attachment 652181
Reply:Originally Posted by Mr. MooseI found that the "Y" fitting did not work well for me.  I think the gas through the torch meats substantial resistance due to the small opening in the torch orifice or gas lens.  The "back purge" part of the "Y" has much lower resistance, particularly if they are just the end of the feed tube inserted into the tape or aluminum foil forming the back purge barrier and thus the back purge gets much more of the flow from the "Y", robbing the torch gas feed of the CFH flow you think you're getting. A dual flowmeter solves this problem, and gives you exactly the pressure and gas feed that you expect through the torch.
Reply:I use a simple T/splitter after the regulator on my tank, one side goes tot he TIG machine and the other for the backpurge. Just a simple hose to a control valve with about 12" of hard line coming out of it.  Works great, no need for two regulators or other nonsense.
Reply:The bend I welded up was 409 stainless... Does that make the welds dirtier?ThermalArc 181i | Lotos WS200
Reply:without Stepping on some toes back purging isn't To make things pretty... It's to keep the Material and we are working with Stainless, from sugaring and becoming Crack prone....  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by B_Cwithout Stepping on some toes back purging isn't To make things pretty... It's to keep the Material and we are working with Stainless, from sugaring and becoming Crack prone....
Reply:Originally Posted by B_Cwithout Stepping on some toes back purging isn't To make things pretty... It's to keep the Material and we are working with Stainless, from sugaring and becoming Crack prone....
Reply:I hardly ever do stainless unless it's a coupon, but does it weld different when you back purge it?Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleThere is a new stainless rod on the market that is for stainless and creates a flux on the inside so no need to back purge.I think I threw out the magazine on it though.
Reply:Originally Posted by ttoksNot exactly new, i've used it for year's in the power industry here in Australia welding stainless boiler tube where we have no way to purge the backside of the weld, it's good stuff, produces good looking welds, but is rather expensive.https://www.nationalwelding.com.au/3...ws+A522+R309lt
Reply:needs a decent gap to work it's best, i like 2.5mm (1/10th of an inch), it's very important to dip the wire on the side of the weld pool and wash it over the prep, and not be tempted to push the wire into the middle of the weld pool to avoid getting spur's of un-melted filler wire poking through the root.
Reply:Originally Posted by GambleI hardly ever do stainless unless it's a coupon, but does it weld different when you back purge it?