To hold the centerline on the workpiece will help the device shown in the figure.
Recommend to read
SOLDERING WILL BE MORE CONVENIENT
Metal "crocodile" attached to the soldering iron stand, will simplify the work when joining the two parts: it is held one part, and the second is a tweezer, and you can safely solder.
THE PLOUGHSHARE OF PIPE…
Paradoxically, for many Amateur designers to make a good plow harder than a mini-tractor! And only due to the fact that the tool consists of parts having a curved shape, which can only...