welding cross T profiles

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Hi, can you suggest a good approach to tack and weld the following T profiles forming a cross so that distortion is avoided?I have placed letters to ease the sequence description. Place an apostrophe to signal the opposite (hidden) side for the letter.I'm planning on building an "industrial" window (several small equal pieces of glass arranged in an array) so I'll have many repeated joints of this type and don't want to end with a bow window ; it' supposed to be FLAT.Thanks in advance for helping me outregardsAlex
Reply:I think you'll need to provide more info.Material type and thickness. Welding process to be used. Experience level of the welder/fabricator. Etc.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:The simplest way I can suggest to minimize distortion is, don't weld 100% of all the joints shown.  Use the minimum amount of welding needed to accomplish your goal.  If you try to completely weld those marked areas, you'll probably have a "potato chip" when you're done.Beyond that, we'll need the answers to the questions Dave asked in his post.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Originally Posted by MinnesotaDaveI think you'll need to provide more info.Material type and thickness. Welding process to be used. Experience level of the welder/fabricator. Etc.
Reply:How about with this sequence?Tacks: A - D - E - D' (back side of D) - E' (back side of E)ThenWeld:  D - E - D' - E'I'm in doubt about welding B - G  on both the piece shown and the opposite fillets in the horizontal piece to the left to compensate.What do you think?thanksAlex
Reply:If I had to stick weld it, I would use a 3/32" rod. I'd prefer to mig or tig weld it.I would put a slight bevel on A,  D'-E', then tack A (which will basically be welding it...), D'-E'.I would weld B-G, and D'-E'You could grind A, D'-E' flush, if you want.Done.Rich
Reply:Originally Posted by steelsurgeonIf I had to stick weld it, I would use a 3/32" rod. I'd prefer to mig or tig weld it.I would put a slight bevel on A,  D'-E', then tack A (which will basically be welding it...), D'-E'.I would weld B-G, and D'-E'You could grind A, D'-E' flush, if you want.Done.Rich
Reply:You need to understand why and how things warp when welding. Welds always pull towards the weld when cooling. So if you weld say A in your drawing, it will naturally want to open up at D-E. If you weld D-E, it will want to open up at A. Same applies to tacks, but not as bad. Many times guys will use this to their advantage. They will deliberately bend the parts so there is say a gap at A, but be tight at D-E. When they weld and A pulls, it pulls straight and a matching gap opens up at D-E. The other thing to remember is that if you need something dead flat, then don't weld that until things are better restrained. So if you want it flat in the A/D-E plane, weld the plain at 90 deg instead 1st. This may warp, but the other plain will usually stay flat..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by DSWYou need to understand why and how things warp when welding. Welds always pull towards the weld when cooling. So if you weld say A in your drawing, it will naturally want to open up at D-E. If you weld D-E, it will want to open up at A. Same applies to tacks, but not as bad. Many times guys will use this to their advantage. They will deliberately bend the parts so there is say a gap at A, but be tight at D-E. When they weld and A pulls, it pulls straight and a matching gap opens up at D-E. The other thing to remember is that if you need something dead flat, then don't weld that until things are better restrained. So if you want it flat in the A/D-E plane, weld the plain at 90 deg instead 1st. This may warp, but the other plain will usually stay flat.
Reply:Originally Posted by DSWYou need to understand why and how things warp when welding. Welds always pull towards the weld when cooling. So if you weld say A in your drawing, it will naturally want to open up at D-E. If you weld D-E, it will want to open up at A. Same applies to tacks, but not as bad. Many times guys will use this to their advantage. They will deliberately bend the parts so there is say a gap at A, but be tight at D-E. When they weld and A pulls, it pulls straight and a matching gap opens up at D-E. The other thing to remember is that if you need something dead flat, then don't weld that until things are better restrained. So if you want it flat in the A/D-E plane, weld the plain at 90 deg instead 1st. This may warp, but the other plain will usually stay flat.