This is an interesting statement I often get from people who have not used Fast Tracks assembly fixtures, and never from customers who have....
People who have never used a Fast Tracks fixture assume that the aluminium will act as a giant heatsink, drawing heat away from the soldering iron into the aluminium resulting in a poor solder joint. And I can understand why it would be easy to come to that conclusion when one first sees the fixtures, but there is more to the design than meets the eye...
The fixtures are designed in such a way to eliminate this problem. First, the PCB ties are made of fiberglass, which is one of the best heat insulators available. Second, the rail actually sits on top of the PCB ties and does not make any contact with the aluminium fixture. So when soldering it is impossible for the heat to transfer from the rail to the fixture.
The bottom line is that Fast Tracks assembly fixtures do not act as a heat sink at all, and you can solder the ties to the rails with any ordinary 35W soldering iron.
