Which side would make a stronger weld

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Hey everyone, I have a 3/8" thick s/s with a 2"OD tube going through it (pictured)Would the weld be stronger on the inside,outside,or both ?Thanks for reading. Attached Images
Reply:What is it for? What process? And are you gonna back purge those thin tubes when welded?I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:If you are going to tig it,Fuse the inside and use filler on the outside. No purge should be needed. Is this for sanitary, or something else?Sent from my SGH-T989 using Tapatalk
Reply:Using a tig,going to be a intake manifold.
Reply:Me personally, I would tack it up good so it don't pull all over the place, and weld both sides. Let it cool completely in between passes, and definately back purge it, or those tubes will be a mess inside.I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:Will do,thaks
Reply:Thanks*
Reply:I would weld both sides like Mike said. I wouldn't purge it because I know I could weld it without sugaring the inside, a little color on the inside wouldn't hurt a thing. If you are unsure about sugaring the inside purge it or you could ruin a nice piece of stainless.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:It's common practice on exhaust manifolds to weld the inside fully and do two tacks on the outside.
Reply:^ Interesting point. I have never welded a manifold. But like Mike said... I would weld both sides. Walk the inside, freehand the back side.
Reply:scarecrow37209One measure of a novice welder - is they weld everywhere they possibly can.I'd weld both sides - triple pass - stick, wire, and TIG.It will be stout to destruction - all three field will be represented - and no critics.Opusp.s.  A weld is only as strong as the thinest wall - any weld larger is detrimental.Last edited by OPUS FERRO; 10-25-2013 at 01:28 AM.Reason: pls.
Reply:lol... definitely getting some strange suggestionsit's only 16ga tubing guys...First of all why do you care about which is stronger if it's just an intake manifold?If you weld the outside (fillet weld around the outside of tube) you WILL need to purge the inside. You do not need to purge anything for the inside.Recess the tubing 1/16" below the face of the flange and weld around the face to create a nice smoothed fillet like soAnd on the other side just put like four 1inch long stitches equally spaced around the outside, like soLast edited by MikeGyver; 10-25-2013 at 03:49 AM.Welding/Fab Pics: www.UtahWeld.com
Reply:Originally Posted by SquirmyPug I wouldn't purge it because I know I could weld it without sugaring the inside,
Reply:I do outside welds like that all the time. If I don't bother purging for whatever reason then most of the time I can get it to come out just fine, sometimes there will be a little bit of suckback or scale, and occasionally a little sugaring...If it's something you care about then purge it or you risk sugaring the hell out of your project...  Those are easy to purge anyway, set the flange on the table with the pipes coming up and drop a purge line to the bottom with a brass air muffler on the end to diffuse the flow... you don't even need to tape anything, just let the tube will up with argon for 10 seconds.Welding/Fab Pics: www.UtahWeld.com
Reply:I think it being leak free would be more important than the strength, vibration is going to be your biggest enemy so making sure you have support for anything that could vibrate and cause stress fractures is likely to be more important than which of the two welding methods will be stronger.Just curious, what is this going to be a manifold for and what kind of carb/throttle body is getting put on the other end? I'm trying to get some idea of how much weight is going to be flopping around at the end of the tubes and how the whole works will look when its done.