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Soldering question

Whitephrog

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...actually related to my previous post about a DR2 wiper motor.

I decided to rebuild/restore my DR2 motor which as original to the new Whitephrog. Everything cleaned up nicely. The body looks nearly new. I have a new bush kit to install.

So here's my problem. There is a reddish orange wire which runs from the rear of the motor near the terminals to the cap. That wire accommodates the self parking aspect of the motor. I removed the old tattered wire and found new wire of the appropriate size and color. Tried to solder the new wire to the terminals in the rear. After trying several times with several different techniques, I've been unsuccessful. This should be quite simple but for some reason it's not. Got me to wondering if the old solder and new solder are incompatible.

Any ideas about what I'm doing wrong?
 
If the old solder is badly oxidized, you'll need some flux to make it work. Depending on the size of the wires and terminals, you might need more heat too. Get some light sandpaper and make the wires and terminals shiny. Radio Shack used to carry small tubes of rosin flux, hopefully they still do.
 
I do most of my soldering with a propane torch (usually attaching terminals to wires so nothing nearby to destroy). Flux core solder for electrical and a touch of the torch. I hate waiting for the solder gun to get everything hot enough.
 
For all electrical work use rosin type solder and flux. The flux is available at most any hardware store or home store such as Lowe's in small tins for under $5. Look for "soldering paste". Use that with a clean well tinned iron and you shouldn't have any problems making the connection. If you want to remove any excess flux after the job is complete it cleans off with isopropyl alcohol.
The basic premis of soldering is to heat the parent metal up to the point the "pores" or grain of the metal opens up and then the solder can flow down into those areas to bond. You can't get a good connection heating the solder, it won't have anything on the parent metal to grip on and will fail. Heat the parent metal to the point where the solder melts when you touch it to the parent metal and you're there.
 
I assume you're soldering to a surface that was soldered originally; if it was just crimped to the wire, it might not be a solderable surface.

You can solder only to copper-containing metals (brass or copper) in any practical way. You can also solder to nickel plate and maybe a couple other plating metals that sometimes are used on solderable terminals, clips, and so on. Soldering to steel is possible, but it takes a special flux which is invariably acidic, and will corrode the connection unless you clean ALL of it off. That's nearly impossible. It's also possible to solder to aluminum, with special materials, but don't even think about it until you're comfortable soldering to copper or brass. Many anticorrosion metal surface treatments, even on otherwise solderable materials, can make the surface unsolderable unless you sand them off.

It's best to use a radio/electronic solder, because such a solder will have the right mix of metals, the right melting point, and won't be too thick to melt easily. These contain flux, so extra flux is not strictly necessary, but it can still help a lot. Be sure it is NOT ACID! If it's marked as rosin flux, or radio or electronic flux, it's OK.

It's absolutely necessary to clean off ALL corrosion from the surface to be soldered; after 40 years of use, most terminals in LBCs have a goodly corrosion layer. Sand it until it's bright and shiny, then clean it of all sanding grit. You then need a soldering iron that's powerful enough to heat the connection to the point where the flux sizzles. When the connection is completely hot, apply the solder to the connection, not to the iron. (Sometimes a little solder on the iron's tip will help transfer heat to the connection, though.) If you've done everything right, it will flow instantly and coat the whole thing really nicely.
 
I was under the hood (oops! bonnet) today and looked at the tab in question, where the wire is connected. It appears to be a steel tab with the wire spot welded to it. So, if yours is the same as mine, no wonder you're having problems soldering it.

I would connect to this by drilling a small hole in the tab, after bending it up carefully, and using a solderable lug and small screw (2-56 or at the largest 4-40) to make the connection.

If there is a piece of the original wire still connected, you might be able to solder to that.
 
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