tigging 304 stainless steel tube

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HiOnly played with a tig a couple of times but have been bought a DC tig for Christmas so have not used it yet .I have just been cutting out the pieces for my project. They consist of  35mm and 50mm diameter stainless steel tube 2mm and 3mm thick to form 45° elbows, I guess that at these thickness's I don't need to V the joint out.Sorry for the dumb question.Pete
Reply:There was no question.-AaronJet 17.5" Drill Press1942 South Bend 16x84 Lathe1980s Miller 320A / BP --- 2013 Power Mig 2562012 Jet 7x12 Horizontal BandsawVictor O/A Setup
Reply:He wants to know if he needs to bevel or not at those thicknesses. I don't tig or i would answer your question.Fireman BillHH 210 MVPMM 211 Spoolmate 100Lotas LTP5000D PlasmaOxy/Accet (Victor)Wards AC/DC buzz box30 ton old hyd pressA few brand name toolsA bunch of cheap toolsA wife to worry me and4 dogs to supervise me
Reply:@ pete - not a TIG pro.  Believe there is no need to bevel out the joint prior to TIG autogenous (i.e. without filler) tacks and subsequent welding with filler.   Other pros will chime in.  Be patient....."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Nope no need to bevel the pieces. For the 3mm around 105-110 amps should get you close to where it should be, the 2mm will require a little lower amperage. If you need to get full penetration welds you will need to purge the back of the weld so it doesn't sugar.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Thanks for the info, at that thickness I thought it would not need to be bevelled.Pete
Reply:Originally Posted by SquirmyPugNope no need to bevel the pieces. For the 3mm around 105-110 amps should get you close to where it should be, the 2mm will require a little lower amperage. If you need to get full penetration welds you will need to purge the back of the weld so it doesn't sugar.
Reply:Originally Posted by peteHiOnly played with a tig a couple of times but have been bought a DC tig for Christmas so have not used it yet .I have just been cutting out the pieces for my project. They consist of  35mm and 50mm diameter stainless steel tube 2mm and 3mm thick to form 45° elbows, I guess that at these thickness's I don't need to V the joint out.Sorry for the dumb question.Pete
Reply:With stainless steel tube/pipe, Your going to require a purge inside the tube to prevent sugaring of the weld. You have 2 choices to back purge. You can purge the inside with argon or you can use SolarB weld flux as stated in the insides of each piece.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:What are the parts for?You could go either way, I'd probably V it out a little and fill it in with 1/16" filler.Welding/Fab Pics: www.UtahWeld.com
Reply:HiThe parts are for an exhaust manifold for a small 2 cylinder diesel engine. I have looked at solarfluxB but up to now can't find it in the UK, may-be we have an equivalent flux ?  It is on Ebay from the US but the postage makes it very expensive. I may have to set up a back purge system.ThanksPete
Reply:You may find that getting (anywhere near) full penetration fusing 3mm thick tubing is unrealisted. It'd probably fuse a root and fill the bevel with rod on the 2nd pass.Like this:sch40 stainless (3.68mm wall)... fairly similar.Last edited by MikeGyver; 12-26-2013 at 09:15 PM.Welding/Fab Pics: www.UtahWeld.com