# soldering 4 gauge wire

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#### livehho

##### New Member
I always crimp and then solder the terminal lugs to the wire. Until now I was mostly dealing with 14 - 10 gauge wires/terminals.

Yesterday I tried to solder a 4 gauge wire. It didn't even got hot enough to melt the solder.

I use a Weller WP35 (850 degrees F)

My question is, how many degrees F are needed in order to solder a 4 AWG wire?

##### Banned
The same that are required for 40 gauge wire.. That much copper will disipate the heat though so you have to get it hot fast. It's not the degrees F you have it set to that's the problem it's the power output.

#### livehho

##### New Member
The same that are required for 40 gauge wire.. That much copper will disipate the heat though so you have to get it hot fast. It's not the degrees F you have it set to that's the problem it's the power output.
so I should be looking for soldering irons with higher power output? any suggestion? thanks

#### crutschow

##### Well-Known Member
A 35W iron will barely warm a 4 gauge wire, as you found out. You need at least a 250W gun or a propane torch.

##### Banned
A pencil torch is probably the cheapest solution. Be liberal with the flux, the torch will oxidize the wire in a hurry.

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#### tcmtech

##### Banned
I generally use the propane torch for anything over 8 gauge. Turn your heat way down and watch your solder flow. When the solder starts to flow freely remove the torch flame.
If you have never done torch soldering I would recommend a practice run or two! When you familiar with it its very easy.
When doing larger connections try to heat up the joint quickly and apply the solder fairly fast. Large wire conducts heat very well and can also wick solder up several inches into the plastic covering if the heat is put on too slow or held there to long.

You want to heat up the area your soldering, but as little of the rest of the wire as you can.

#### livehho

##### New Member
I generally use the propane torch for anything over 8 gauge. Turn your heat way down and watch your solder flow. When the solder starts to flow freely remove the torch flame.
If you have never done torch soldering I would recommend a practice run or two! When you familiar with it its very easy.
When doing larger connections try to heat up the joint quickly and apply the solder fairly fast. Large wire conducts heat very well and can also wick solder up several inches into the plastic covering if the heat is put on too slow or held there to long.

You want to heat up the area your soldering, but as little of the rest of the wire as you can.
I think I'll go with the torch method (a 250W soldering station is more than $500).. it would be great if there were some YouTube videos or something. Anyway.. thanks a lot for the help #### Sceadwian ##### Banned It's not exactly complex liveho, apply flux, apply torch heat, apply solder, when solder starts flowing well remove torch. Aside from that no video is going to help you, just practice. #### Leftyretro ##### New Member Well at the cord bench in the electric shop at my refinery they used solder pots for that size wire/connectors, not try and use an iron or torch. Lefty #### picbits ##### Well-Known Member I've used torches in the past to solder fork lift truck connectors. The actual connectors themselves are like small solder pots. I stripped the insulation on the wire and applied flux. Then on the contact I applied a small amount of flux in the "pot", chopped up some solder bar and put it in the pot. Then I heated the pot up with the blowtorch until the solder was just melting. I added more solder until the pot was full then heated up the cable a bit. While keeping the heat on the pot with the blowtorch, I slowly put the cable into the pot and the cable wicked up the solder. Adding more solder to both the pot and the cable until both were saturated and the joint looked good. Then the most important part - go away and leave it for half an hour. If you mess about with it while its hot or move it then you can ruin the joint or end up with some interesting looking "tatoos" #### stevez ##### Active Member A large wire implies a lot of current. An electrical engineer who worked with power systems warned me to never solder connections. He suggested using the correct materials and tools to get the necessary bond. He explained that under high current (abnormal but possible situation) the solder could melt and as the solder melts the conductivity of the joint becomes a huge source of heat. Brazing or some other high temp method was recommended for my purposes at the time. All I was doing was soldering house wiring to reduce noise. In your situation it may be impossible for you to see high currents so maybe the advice just doesnt' apply. #### crutschow ##### Well-Known Member Most Helpful Member I think I'll go with the torch method (a 250W soldering station is more than$500)..
Sears sells a 150/230W gun for $37 and a 150/400W gun for$60.