cjarnutowski wrote:....I am welding a 3"x.25" round tube to a 24"x24"x.25" plate, dead center. The material is steel and the process is TIG. I was hoping to hear some of your tricks for preventing the plate from "cupping" up toward the post on the side of the weld...
What can you tell use about the intended use of this welded item? Static, dynamic, cyclical loading? Access to oxy-propane or oxy-acet torch?Option #1
. Micro tack the 1/4in round tube to the surface of the 1/4in assembly plate. 4ea 1/2" long tacks at cardinal positions on the clock. Cut 2ea 3/32" TIG filler wires into 24" lengths. Set aside. If available, sever another section of 2ft x 2ft x 1/4in steel plate as fixturing for your 1/4in assembly plate.
Stack up, from bottom to top. 1/4in fixture plate + 3/32" TIG filler at third-points on the surface of the 1/4in fixture plate + 1/4in assembly plate. Clamp the fixture plate to the assembly plate, bi-diretionally. This sandwiched arrangement "preloads" the system and introduces a micro-camber. Note, a fixturing plate is not req'd and you can easily camber the assembly plate directly to your welding table.
Weld the unit in quarters (e.g. 12 to 3 o'clock, then 6 to 9, then 6 to 3, and finally 12 to 9). Allow unit to cool, completely. Unclamp the assembly plate from the fixturing plate (or weld table). Inspect and FlameStraightening, as required, via oxygen-pro/acet torch by applying heat to the BOTTOM of the 1/4in plate.Option #2
. Disregard the 1/4in fixture plate approach. PreHeat the tube and entire assembly plate to 150F. Tack, followed by weldout a la the above technique. Allow the unit to cool. Inspect and FlameStraighten.
Unsure if you are experienced with oxy-fuel and FlameStraightening. We could walk you through the baseline technique if you have access to the equipment.
Understand that you cannot PREVENT heat from doing it's thing. Ever. Even placing a Battleship or M1 Abrams Tanks on the system as fixturing will not prevent warping. Minimize, yes. Eliminate, no. Atoms within the Elements are of star dust. Strong and Agile like the HoneyBadger.
Approach heat as a "tool". Apply to your advantage to affect the geometry during weldout and minimize distortion. In this situation, TIME between welds and attack approach are your allies.
Purpose, then passion; practitionership, then proficiency. Process and patience, talent and hard work. That's the discipline.