[southofheaven]

Would speed cooling mild steel with an air hose be an effective way to reduce distortion?

[weldin mike 27]

It might be not be fast enough. People use wet rags behind the welder to stop distortion. Or clamp it to a big block of steel /aluminium. Or copper. Presetting (bending the opposite way to the possible distortion) also is very beneficial.

[southofheaven]

If you were to attempt to pre compensate for the distortion wouldn't that almost be like taking a shot in the dark and chancing to over or even under compensate?

[LtBadd]

Would speed cooling mild steel with an air hose be an effective way to reduce distortion?

Mild steel really doesn't move that much, especially compared to 300 series stainless. Perhaps a photo or description of the part your concerned about would help someone provide a specific answer

[weldin mike 27]

Make some test joints, of the same one you are planning. Clamp a few, in different ways, varying amounts, and see how they turn out. And then you will have a good starting point

[Otto Nobedder]

Pre-stressing weld fits for distortion is an arcane art, developed only from experience.

The suggestion to try a few samples before the money weld is solid. (Developing experience.)

I also agree that carbon steel distorts far less than stainless, and can sometimes be corrected after in the vise. It can also be corrected with ox/acy and a quench on the opposite side.

Learning how each particular weld will draw will help you fit for it the next time, and reduce the rework to resolve the problem.

Steve S