Connecting different gauge wires for bus line

[DavidEnghauser]

I am installing a 30ft. section of 009 gauge track with a DC locomotive. Can I use some scraps of 14 gauge wire for part of the bus line, and then 18 gauge for the rest of the bus line? I would solder them together. Start with the 14 gauge from the transformer, then finish with the 18 gauge. I don't have enough of either for the full run.

[teedoubleudee]

Current is always restricted by the smallest wire gauge in such a circuit. Think of it like connecting a piece of 15mm water pipe between two pieces of 22mm water pipe. Water will only flow at the rate dictated by the 15mm piece.

Edit, if you do use different gauges the biggest should be nearest to the power source