The recurve form is screwed into the vise so it doesn't move. After steaming the tip plus strap for about 15 minutes per each 1/4" of thickness, it's inserted into the opening between the vise and form, set before-hand to be just the right size, and clamped down snug and then the curve is bent in. This of course is done in as little time as possible, which is very little since my steamer is right next to the vise. The other end of the bow, billet in this case, is supported by a stand, of which you can only see the base in that pic, and tied off so I don't have to sit there and hold it till it cools. Also the support is at the same height as the tip so no twist is introduced
As to prepping the recurve before steaming. I work the tip to one growth ring and also into a very shallow D section on the belly side, plus I sand the edges. I find that by doing it this way there is less likely hood of splinters lifting
Now that is a mystery pic. What is on the other end of that bow? I guess a rope tied to a truck bumper.
If you need a truck to hold your steamed bow/billet then you are doing something wrong.
P.S. In case anyone can't figure it out, this picture is taken from above
