I think I know the answer to this one, but not sure. I used to buy those Atlas joiners with wires on them for feeders, but have learned to solder well enough to do my own, as I know most of you do.
Since I was used to the Atlas ones, I soldered to joiners… but is it better to solder to the rail itself?
Solder to the rail. It will give smoother track, maybe.
If you solder to the joiner and at the same time solder the joiner to the rail there is no difference, from an electrical standpoint.
To briefly answer your question, what you’ve done so far is OK, but I would go the extra step and solder the rail joiners to the rails.
You might want to visit www.wiringfordcc.com - it might be a little overkill sometimes, but there’s a lot of good pointers for wiring. The rule of thumb this guy uses (and I try to follow as well) is that every piece of rail should be soldered to something, whether it’s a feeder wire or the next rail.
Electrically, it’s better if you have a continuous joint. You get that with the feeder soldered directly to the rail, and the adjacent rails soldered together at the rail joiners. The problem with soldering to the rail joiner and then not soldering that joiner to the rails is that you’re relying on a mechanical connection (i.e. physical contact between the joiner and rail) to conduct your electricity. In reality, this will probably be OK most of the time, but eventually, it could fail due to the joiner becoming too loose, insulating crud getting between the rail and joiner, etc.
Expansion/ contraction mainly from the benchwork as well as any faulty or cold solder joint could cause poor electrical connection. Run all the feeders or jumpers directly to the rails to eliminate this possibility. Rails fed off the bus will give a more even voltage as well.
Bob K.