Soldering correctly wire to spade

[JHZR2]

One of the speakers in my 1991 300D went out. Open circuit.

I have a proper soldering iron, and a soldering gun.

I can never seem to get enough heat at the right places, and my work looks like trash.

I found some well reviewed drop in replacement speakers, but they just had two male spade terminals. The old OE speaker had similar with the wire just slightly soldered to it.

I’m trying to solder the OE DIN connector to the new speaker. Not having much luck with a good looking, quality job.

I ran the wire through the hole in the spade, wrapped it around. It had some rosin flux on the wire. Used a weller soldering gun. I just can’t get enough heat to get it to flow without it being too hot elsewhere. And when I get it to flow (0.6mm 60/40), it looks like this:

Added a bit more to the rear of each spade and it looks like this:

I don’t know if I should start over, add more solder, or what. How do I make this better? Maybe I should have just butt jointed to the OE wire. Or what? Does it really matter for this? The end of the DIN connector does meter out to 3.6 Ohms.

Thanks!

 

[JHZR2]

This is kind of what I’m thinking for the end point, there is some strain relief on the wire I guess.

The oe wire was similar with a rubber pad (I used electrical tape) and necked in. But this speaker has a bigger magnet.

 

[Nukeman7]

Speaker wires carry minimal current; therefore, leave it as is. Most manufacturers and all aftermarket speakers are normally connected with friction fit spade tongue terminals, so any solder joint will have better conductivity. Your current solder joints are good for life unless you choose to remove them in the future.

 

[JHZR2]

Speaker wires carry minimal current; therefore, leave it as is. Most manufacturers and all aftermarket speakers are normally connected with friction fit spade tongue terminals, so any solder joint will have better conductivity. Your current solder joints are good for life unless you choose to remove them in the future.

Thanks. I figured probably dry wrapping them might even suffice if not for road shock and vibration…

But how do I make them look nicer? Would a more heavily tinned tip help since then there’s a big bulb of wet solder to wick in?

 

[Propflux01]

Part of the issue is that you are not tinning your wires. I can see the copper plain as day. The solder gun you have is not the best choice for soldering wires like that. A pencil-type iron is much better.

A bit basic, but informative:

 

[Nukeman7]

Also, are you using 40/60 lead/tin alloy solder with rosin core flux? It looks like the spade terminals might have oxidation on it that should be cleaned off with a small wire brush wheel on a Dremel tool. Your rosin paste flux helps, but the metal needs to be abrasively cleaned first. The terminals need to be heated as much as the wire strands, but you should attach an aluminum heat sink clip (or alligator clip in a pinch) to dissipate the heat.

 

[vavavroom]

I would twist the wire end and add solder paste. I would not feed the wire end through the hole in the spade. I would want to ensure full contact over the whole length of the wire end with the spade. I would apply solder paste also to the spade. The solder paste will conduct heat very well. The solder will wick into the wire end and also fuse with the spade.

 

[vavavroom]

I would use solder paste because it makes for swift heat transfer and gives a neat solder joint. In the example, I fed the wire through the hole in the spade and soldered both sides. You don't have to use the hole. Just lay the wire end flat onto the spade and solder the full length of the wire end. It takes two steady hands. Again, solder paste makes it much easier.

 

[spasm3]

Just me, but i would have gotten the matching spade connector, and crimped, then soldered the wire to that. You could still desolder that, clean it and use matching spades.

 

[ArrestMeRedZ]

Don't know if this is your problem, but the last time I soldered I couldn't get a proper joint no matter how hard I tried. Was really upset with myself as it was something I used to be good at.
Found out it was the "new" environmentally friendly solder. Found some of the old lead/tin rosin core stuff and all was well again. Then I went back to the store and bought all of the obsolete solder they had.

 

[SHOZ]

I've never had any luck with fancy soldering irons. I just have a couple pencil types 25 and 35 watt. And I use a flux paste first on both wire and connector, heat to melt. Then hold the iron right where I want some solder until the flux is mostly gone. Then touch the solder to tip. If really small I just load up the tip with some solder, heat that to melt. Wipe off any excess flux when done.

 

[Trav]

One of the speakers in my 1991 300D went out. Open circuit.

I have a proper soldering iron, and a soldering gun.

I can never seem to get enough heat at the right places, and my work looks like trash.

I found some well reviewed drop in replacement speakers, but they just had two male spade terminals. The old OE speaker had similar with the wire just slightly soldered to it.

I’m trying to solder the OE DIN connector to the new speaker. Not having much luck with a good looking, quality job.

I ran the wire through the hole in the spade, wrapped it around. It had some rosin flux on the wire. Used a weller soldering gun. I just can’t get enough heat to get it to flow without it being too hot elsewhere. And when I get it to flow (0.6mm 60/40), it looks like this:

View attachment 200439

Added a bit more to the rear of each spade and it looks like this:

View attachment 200440

I don’t know if I should start over, add more solder, or what. How do I make this better? Maybe I should have just butt jointed to the OE wire. Or what? Does it really matter for this? The end of the DIN connector does meter out to 3.6 Ohms.

Thanks!

That looks like a cold joint, there was not enough heat.

 

[supton]

The speaker is taking the solder, the wire isn't. How clean is that copper? I don't think it's taking solder as it's got some level of corrosion. If it won't take solder during tinning, try cleaning or using something like a RA solder instead of RMA, going up a step. Or using more flux. But first clean the wire best you can, fine sandpaper or heck, scrape down it with an Exacto to "shave" it.

Antique Radio Forums • View topic - Tips or tricks to soldering old oxidized copper wire?

 

[meep]

One thing you can try is to pre-solder both parts. Get a layer of solder over the terminal. Then “tin” the wire with a good full soak-through. Then hold the wire against the terminal, using modest heat (30w iron), until they flow. Remove the iron and hold the wire until it bonds. This is not as mechanically sound, but will be perfectly acceptable in this application.

 

[RooflessVW]

But how do I make them look nicer?

Heat shrink

 

[Pablo]

I actually attended 'Solder School" at China Lake Naval Weapons School in the 1980's.

Yeah, that's a fail for hi rel solder joints......

Properly strip and pre-tin as suggested.

You need a proper soldering station. 60W-80W min, small tip. You want heat and you want it now and you don't want the temp to drop. ~850°. I have a Hakko 936 ESD Soldering Station I bought for around $75 in 2008 or something.

Yes, get Pb/Sn solder, not Pb free. Small gauge solder. Everything must be clean. Solder paste is good, but wire solder should work fine as well.

Step one when tip is hot and clean is to form a heat bridge with your tinned wire and tinned contact. The heat bridge is formed with solder between the soon to be joint and your hot tip. bridge formed, solder melts, a little solder is fed and off. That quick 2-3 seconds max.

 

[JHZR2]

I actually attended 'Solder School" at China Lake Naval Weapons School in the 1980's.

Yeah, that's a fail for hi rel solder joints......

Properly strip and pre-tin as suggested.

You need a proper soldering station. 60W-80W min, small tip. You want heat and you want it now and you don't want the temp to drop. ~850°. I have a Hakko 936 ESD Soldering Station I bought for around $75 in 2008 or something.

Yes, get Pb/Sn solder, not Pb free. Small gauge solder. Everything must be clean. Solder paste is good, but wire solder should work fine as well.

Step one when tip is hot and clean is to form a heat bridge with your tinned wire and tinned contact. The heat bridge is formed with solder between the soon to be joint and your hot tip. bridge formed, solder melts, a little solder is fed and off. That quick 2-3 seconds max.

Thanks.

I can’t say that the OE job was much better… and lasted for 33 years.

But I’ll get a better job done. The solder paste looks great. Never seen that before.

 

[JHZR2]

That looks like a cold joint, there was not enough heat.

That’s always my issue.

That’s what I need to learn to fix. I even bought a solder gun sometime back to theoretically get more heat in.

All the components (the spade, the wire) get hot. Too hot to have anything nearby. The wire insulation starts to melt and smoke. Yet I get that.

That’s the quality job part that frustrates me. And I solder something maybe once every 3-4 years so I never really get experience on this sort of stuff.

I would use solder paste because it makes for swift heat transfer and gives a neat solder joint. In the example, I fed the wire through the hole in the spade and soldered both sides. You don't have to use the hole. Just lay the wire end flat onto the spade and solder the full length of the wire end. It takes two steady hands. Again, solder paste makes it much easier.

I watched some YouTube. Solder paste looks like great stuff! I’m going to practice on some little spades like you made to learn, when I have time. Thanks!

 

[KrisZ]

I ran the wire through the hole in the spade, wrapped it around. It had some rosin flux on the wire. Used a weller soldering gun. I just can’t get enough heat to get it to flow without it being too hot elsewhere. And when I get it to flow (0.6mm 60/40), it looks like this

- You need to use flux on both the wire and the connector.
- Heat the connector only, but test the temp by touching the wire with the solder.
- Once the solder flows into the wire freely you know you have the correct temperature. Usually you can remove the heat at this point.

 

[JHZR2]

- You need to use flux on both the wire and the connector.
- Heat the connector only, but test the temp by touching the wire with the solder.
- Once the solder flows into the wire freely you know you have the correct temperature. Usually you can remove the heat at this point.

- I had put a bit on each. The photos may not have shown but I had wiped both with it. (That’s part of my confusion, shouldn’t that direct the solder wicking?)

- I do put the iron on the larger component. All the same the wire gets really hot, insulation starts to soften and smoke, etc.

- I can say that despite the joints looking bad, I did put a decent amount of solder into the wires. You can watch it suck in.

- I’ve always read that but I don’t usually see it. I guess at least somewhat due to my adversity to burning other stuff nearby from it all getting so hot in the wrong directions.

Thanks!!