How to prep 321 stainless tubing

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Im going to be welding up some 16 gauge 321 stainless tubing and would like to get some things straight first. I would like to create a small bevel on the outside diameter and will be deburring the inside of the tubing also; would it be ok for me to use an abrasive roll or will it contaminate my weld? If so what other options do i have? Also, i tried to clean the tubing edge with a small stainless steel brush and it seemed like nothing was coming off, do i just need a bigger brush, should i try an alternate method, or is cleaning with a brush not necessary before welding.Learning the ropes....
Reply:Originally Posted by superchargedv8Im going to be welding up some 16 gauge 321 stainless tubing and would like to get some things straight first. I would like to create a small bevel on the outside diameter and will be deburring the inside of the tubing also; would it be ok for me to use an abrasive roll or will it contaminate my weld? If so what other options do i have? Also, i tried to clean the tubing edge with a small stainless steel brush and it seemed like nothing was coming off, do i just need a bigger brush, should i try an alternate method, or is cleaning with a brush not necessary before welding.
Reply:What diameter and is it code work?sent while goofing off at workLong after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:I will be using 347 for filler. I will also be using acetone. BUT i see alot of people brush the edges off with a stainless brush before cleaning with acetone; i happened to have a peice of tubing with me at loses and tried a small stainless brush there and it did pretty much nothing to the tubing...unless i was being to gentle on it?Learning the ropes....
Reply:Originally Posted by Adam ArcWhat diameter and is it code work?sent while goofing off at work
Reply:321 is very tough. We use grinding disks to bevel and sanding disks to polish.  Acetone will remove grease but not oxidation.  A wire brush will do very little pre weld to remove oxidation.  A file will be better,  but not by much either. sent while goofing off at workLong after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:You are purging too, right?sent while goofing off at workLong after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:Oxidation?Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Depending on where the material is stored, there is oxidation that could effect the weld process. It will muddy the puddle.Long after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:i just bought the material so it looks clean...can i just wipe with acetone and start welding? or is a wire brush a must?Learning the ropes....
Reply:Use a stainless wire wheel on your grinder to remove oxidation on the outside of the tube. You need to either purge the inside with argon while welding or you need to use solarB weld flux on the inside of the joint to eliminate sugaring/porosity on the inside of the root pass due to lack of shielding.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Purging would work better. Solar flux is a one shot deal.sent while goofing off at workLong after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:So if the tube is clean i still need to use a stainless brush to scuff it up correct?Learning the ropes....
Reply:Oxidation can be deceiving on stainless tube/pipe. You don't need to scuff it up so to speak. You need to remove the oxidation.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by snoeproeOxidation can be deceiving on stainless tube/pipe. You don't need to scuff it up so to speak. You need to remove the oxidation.
Reply:I can't say for sure because I've never used acetone myself. Any stainless pipe I've worked with I always rubbed both ends of the pipe with a wire wheel to clean it.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I agree that it is not a must, but you do get better looking results if you do wire brush. Its just one of those things that you have to see for yourself after you try it both ways. Definitely purge If you want the best looking welds---solar flux works great but it also has a tendency to sometimes wick up into the weld bead on the outside. 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:Believe it or not the metals that last the longest against corrosion, oxidize the quickest. That is how they slow the deep oxidation process. 321 tubing is stablized with titanium. The melting temperature is higher, then, mangenese or molebdimum stabilized Stainless Steel. The working temperatures are higher, so you get some nasty scale or oxide coatings on the tubing. They do stuff at some mills that leaves a very hard coating on the 321. You should sand the pipe, you can use 220 paper in an autobody sander. You can use a flap sander inside. You would not want to cut deep scratches into the pipe but fine sanding does not hurt. I would not use acetone. Weld it very slow, and hot, like titanium. Use backup gas inside.                Sincerely,                            William McCormick
Reply:It has been a while since I did this to show backup gas on tubing. However I believe this is 321 tubing welded with 347 weldig wire. I rarely use anything but 347 wire. I also use a hose clamp with puched holes to set and tack the pipe I am going to weld. This was done with back up gas. You can go as slow as you like and really get it right. One puddle at a time.                    Sincerely,                                William McCormick
Reply:Nice William. Yes, 347 for 321 and 347 pipe.sent while goofing off at workLong after the price is forgotten, the quality will remain.Both of my Poppy's 1954 Short Hoods -Third generation to weld with it and teaching a fourthSA 2## - Bought and sold more than I can remember or care to list, 8 in the shop right now
Reply:Any Stainless exhaust work we do, we just give it a lick over the outside edge with the linisher, file any inside dags and a quick wipe with acetone and weld it up.321 is just a high grade Stainless so no real issues.One thing I find helpful though is to use 1 to 1.2mm filler wire as it gives a much better job on exhaust tubes typically 1.6mm or thinner.Regards Andrew from Oz.We are Tig welders, gravity doesn't worry us.Miller Dynasty 350. 350 amps of awesomeness.OTC AVP 300 hybrid wave AC/DC inverter tig. (now retired)Kemppi MLS 230 amp for home, a sweet little AC/DC Tig