Originally Posted by knighthawk
Normally when hammer-welding , if you cool it as you go,with air or water, do you still have to hammer it ? If you hammer it, do you still have to cool it?
In my experience (which isn't unlimited), I think there is more than one definition (today) of Hammer Welding-my understanding is that with the original Hammer Welding that you would Oxy-Ace Weld the area, then re-heat and Hammer out the shrinkage-now, there are those who will say that you should Hammer while the area is still Hot from the Weld, and that does take some practice, but it will work (if you are using Oxy/Ace).
One of the other ideas is to use a Tig (which generally will leave a small Weld Bead), and Hammer the Weld (Planish it). One idea that has come out in the last year or so (from Randy Ferguson) was to Mig the Weld, grind the proud Bead down to about .050 on BOTH SIDES, and the Hammer it flat (stretch it). I have used the Tig method and the Mig method, and both work. There was a feeling that using a Mig (or the Mig process) was creating a "Hard" weld, but in reality, Mig and Tig can both use essentially the same Rod (ER70S6), so I believe it was Randy who first figured it out. I love to use my Tig, but it definitely will shrink the Metal more than a properly used Mig Weld (more Heat). Hope this helps-
Glad to hear you did the deed! Can't wait to see the pictures!