I am trying to figure out how I can solder rail joiners without getting solder on the inside of the rail. Resistance soldering comes to mind. I have a handpiece for this purpose, but no power unit. Will DC work, or will I need AC?
BB
BEST WAY to NOT get solder on the inside rail’s @ rail joiner’s, is to NOT solder them there.
20 guage feeder wires soldered from the outside of the rail’s to a buss wire underneath, is far better. I used solid copper wire and a SEARS hand ratchet-drill to make the holes.
I solder every other rail joiner, sometimes more. If you make sure you only solder from the outside of the rail, you will not have solder showing on the inside. If you do, you are using too much solder. It doesn’t take much. I solder the feeders away from the rail joiners as suggested by Don. I would also suggest that you use a low wattage iron in the 25w to 40w range instead of trying to get the resistance stuff to work. Practice a few times before you do it on the layout and you will have no problem. The trick is to use a hot iron, make sure the tip of the iron has been tinned (has solder on it), tin the wire and the rail where the connection will be made. Make the connection quickly and get out. You will see the solder flow between the rail and the wire when the connection is made. If you work quickly and do it it well, you will not melt the ties. I use a non-corroding flux (soldering paste - rosin based) as well but it is not necessary to do a good job.
Apply the solder to the outside of the rail joiner and the only solder that will get on the inside will be within the rail joiner itself, if you’re concerned about solder getting in the way of wheel flanges.
Without knowing your technique, it is hard to respond, Bruce. ARE you soldering to the insides of the rails? I have only soldered feeders that way, mostly to prove to myself that it could be done. Care must be taken with the flange-paths, as you know.
If you could pre-heat the rails, only partially so as not to melt anything else, and then touch your solder to the outside, as low as you can get it, then touch the iron to the inside for another 3-5 seconds, you should be able to get the solder to flow and stay in something like a flange-safe shape.
I would guess that you are quite adept at feeling surfaces with your hands due to your circumstances, so you would then have to use a file to dress the inside and top of the rail…if need be. Your fingers will tell you when they feel much like any other gap.
I agree with soldering the outside only and only soldering everyother joint. I have never had any solder reach the inside of the rail. At least that was noticeable or to the point that it caused any type of problem with derails.
One additional thought comes to mind, and that is if you do not keep the tip of the iron clean, perhaps some excess could find its way into the inside.
Cletus
Resistance soldering doesn’t care whether it’s using AC or DC, just as long as there’s plenty of it. Some use special resistance soldering power supplies, some high-powered car battery chargers, and I’ve even heard of people using a Lionel ZW(old, not the new high-tech version).
A resistance soldering unit is something that I’ve had on the waiting list to buy/build for several years, although I’ve never gotten around to it.
In your situation, resistance soldering sounds like it would be about the best choice.