Need sugestions on keeping my project from deforming

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I am going to be welding up a frame for a T-Bucket rat project.  I can MIG weld fine, I have a Millermatic Passport that I have a tank (75/25) and am running 220V with it.  Its rated for 3/8" mild steel.The frame is 2" X 3" X 1/4" mild rec. tubing.What I want to avoid is the heat from warping my frame.  So I was thinking that I would V out the seams and weld 1" sections.  Like 1" on one side then 1" on the other side of the frame and flipped ( so after a top left weld, wait for it to cool, then I would do a bottom right weld)  I was going to do some beefy tack welds every inch.Anyone have any other suggestions?  (please no 'take it to a shop' comments)Thanks!
Reply:you need to balance your welds.  weld on one side of the member and weld on the opposite side of the same member.  That way the welds will complimentarily pull against each other.  then move to another area and weld there balancing your welds.  When the first welding area has cooled some go back and weld somemore.  Keep this up till you're finished.  You will probably still need to do some flame straightening, but not much if you are lucky.
Reply:Weld the kick up z section while it is clamped to a welding table. Then tack the whole frame together and install the transmission crossmember, clamp it to the welding table nd start your balanced welding plan. Don't try and do these like its  sheet metal body panel, it is a structural element, you need to have good welds without a bunch of cold starts in it, good hot full penetration welds. If it warps a wee bit, just repost and we can tell you how to straighten it.
Reply:Only way to do it right is to clamp it down to something solid. If not no matter how hard you try there will always be some movement.Frame table:
Reply:Thanks guys.Some of the things will not be able to happen like the trany X-member.  But I was thinking of welding a 2" X 3/16" section of flat bar to it to hold it in place.I have a table I built that I was planing on clamping it down to.  But in the past things still seem to warp with being clamped.  When I unclamp them they spring to their deformed shape.I'm hoping that with clamping it down well and doing the 'counter welds' will make most of the difference.Now I am thinking of doing some internal gusset plating.  Like I would drill some 1/2" holes near the seams and put a 1/4" plate inside the rec. tubing and weld in the holes to attach them.  If I do it right then at least in one dimension there should be little to no deformation.
Reply:when you weld on something clamped to the table, let it cool completely before you unclamp it. I have a set up in the garage for welding up hand and guard rail. clamp the **** out of it to some beefy angle and channel. Let it cool to the touch before unclamping. It usually works out for that ends up being overnight.Weldanpower 225 G7Ironworkers Local #24
Reply:Yeah I have done that and still get deformation.  I think that I must over heat the metal a bit to much.
Reply:I have found that using allot of tacks before doing actual welding helps as well.
Reply:Have any friends?  The top race teams use two guys and weld opposite sides simultaneously . . . while clamped in the jig.
Reply:Originally Posted by Scott Youngyou need to balance your welds.  weld on one side of the member and weld on the opposite side of the same member.  That way the welds will complimentarily pull against each other.  then move to another area and weld there balancing your welds.  When the first welding area has cooled some go back and weld somemore.  Keep this up till you're finished.  You will probably still need to do some flame straightening, but not much if you are lucky.