dumb soldering question

Model Railroader Electronics and DCC
1

Ok so I was feeling dumb today and couldn’t figure out how to take the trucks off an athern gp-9 to do the dcc conversion like what was posted here this week. So while taking off the spring connectors to the motor I soldered a lead to the L on the top of the truck. I soldered or tried to solder the other rail lead on and could not get it to stick. What the heck. All my other soldering seems to have stuck except on the metal sides of the truck. What am I doing wrong. I use 60/40 rosen core thin solder for electronics. I wiped down the trucks with a clean rag to try to get all the oil residue off. I tinned the tip of the iron and dipped the solder in the flux. The wires were tinned but nothing stuck. should i have sanded or roughed up the surface(looks like aluminun or something coated?). So this is my off day any help would be greatly appreciated.

thanks

mike

2

You can try using some fine sandpaper on a small spot. Apply a little flux and see if you can tin the area - get some solder to stick to it. If you can, then solder your wire to the tinned spot. I wouldn’t be surprised if it might be made of a metal which may not accept the solder. I picked power from the frame by either drilling a hole and putting a screw down into the frame or soldering to the bracket that used to hold the cab lamp.

Jim

3

thanks. appreciate the infp. I was haveing a dumb day yesterday and didn’t even put 2 and 2 together that power is touching the frame at the pivot point of the trucks. Now hopefully everything else will go smoothly and I can finish this project.

Mike