Hey All, I'm building a lift out bridge on my layout, and I'm at the point of installing copper contacts at each end of the liftout, (please checkout the video "Making a liftout bridge PT2 DG Modelworks on Youtube) I'm usuing his method for this project, my problem is soldering the copper contacts to my wire bus, the solder will not adhere to the copper, is there something I could do to fix or get around this problem? Take Care Trainsrme1
Two things. A light sanding of the spots on the copper where you wish solder to adhear. Make it shiney 600 grit is fine for this. then apply a rosin flux on the contact area. Apply solder to that spot (which is called tinning) then apply wire and solder wire onto contact. Clean with alcohol to remove rosin flox so it doesnt attract dirt.
Shane
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TrainsRMe1 ...my problem is soldering the copper contacts to my wire bus, the solder will not adhere to the copper, is there something I could do to fix or get around this problem?
...my problem is soldering the copper contacts to my wire bus, the solder will not adhere to the copper, is there something I could do to fix or get around this problem?
Shane made good points.
One additional: you might not have enough heat in your iron to get the copper hot enough to accept the solder.
Ed
The others have made good points...
The surfaces to be soldered must be clean! Oils and corrosion make it difficult. A quick application of fine grit sandpaper works wonders. Dull (oxidized) copper doesn't like solder, but bright shiny copper does.
Flux helps a lot. Clean it off afterwards.
Heat is important, if the work doesn't get hot enough the solder will not flow. Use a tip suited to the job, a small pencil tip doesn't have the thermal mass and its temperature will drop when the copper absorbs the heat. A larger chisel tip would work better. If you don't apply enough heat a cold solder joint is often the result.
You want the iron hot enough that the task is completed quickly. The heat will have less time to travel.
Support the work pieces, if it moves while the solder is still in its plastic state a cold solder joint will be the result. Whatever clamps onto the copper piece will also function as a heat sink too.
To clarify: you want to use additional flux when soldering the joint. Get a good low-halogen no-clean formulation. You can use either a paste or liquid type depending on what you find easiest to use in a particular situation.
The flux excludes air and breaks any surface contamination. Since you are heating the joint until the solder melts in contact with it, you will find the solder readily 'wets' the metal underneath the flux pool.
Heating the solder to try to 'tin' the joint or blob metal on it is counterproductive at best. (Look up what killed Joseph Kennedy Jr. -- respect his memory.)
This might be an application for resistance soldering if it is somehow difficult to get enough heat to the region of the joint with a regular iron.
Overmod This might be an application for resistance soldering if it is somehow difficult to get enough heat to the region of the joint with a regular iron.
No need for one of them fancy resistance rigs: