Soldering Irons

[secrtwpn1]

Folks,

I'm trying to solder Deans connectors onto some wires. I'm using a 40 watt iron. I have a big mess. I use rosin core solder. What brand/wattage do you folks use????????? I've been told to use a 30 watt iron....

Thx
Farlan

[Ralph --- SSBN 598]

If you have globs of solder on parts then you have too much solder.

Dry fit your wire to the part.
For small parts I find rosin core to be a bit more work because you have to melt more solder than needed to get enough rosin on the part before the solder.
Hardware store will have small tins of flux.
I use a cotton swab or small piece of plastic to apply flux on the part and the wire.
Heat each part separately and touch just a little solder on the part to put a thin covering on the part and the wires.
The for plugs I hold the plug up so the wire is push up in to the socket.
I apply the heat to the plug while gently pushing on the wire.
As soon as the part is hot enough to melt the solder, the wire will melt as well being it heats more quickly.

More solder does not mean a better connection.

A thin coating on the large parts and coating the wire where you can see the solder go from one side to the other making all the wire silver is more than enough solder.

40 watt should do the parts we use.
Too much heat and the plastic on the plug will melt, the wire insulation will shrink back away baring more wire than you want bare. (I always use heat shrink tubing on connections)

Pre heat the soldering iron for about 10 minutes before using.
If the iron is not up to temp, the parts will draw heat from the iron and the solder will not flow.

[secrtwpn1]

So perhaps my issue is using the rosin core solder. I'll get regular solder and flux that is separate.........

[secrtwpn1]

PS..................What exactly does flux do?

[salmon]

Cleans the area and enhances solder flow.

[ccontrol]

Flux cleans the surfaces and allows the solder to flow onto the joint. That's why it is combined with the solder. You should be using good quality rosin-core solder if soldering electrical connections. Never use acid core unless you are soldering a birdcage. Use a small diameter 63-37 (60-40 is close enough) alloy. Wipe the iron tip on a damp sponge before each joint or small group of joints. After wiping, touch the end of the rosin core solder to the tip of the iron just before you move to the joint. That will promote quick transfer of heat to the parts. Takes a little practice and it helps if someone can show you how just to get started. I was taught to solder to NASA specs by a Navy Chief while earning my Electronics Merit Badge in the Boy Scouts. Used those skills all my life. I do use separate liquid flux when soldering brass railings on my tugboats. It lets me flow the solder very nicely to closely simulate welds and not allow too much to clump. Get a manual de-soldering pump and some copper wicking braid too. You'll find out why. Good Luck.

[ccontrol]

I forgot to add that everything Ralph said is spot-on too.

[Ralph --- SSBN 598]

Rosin core solder will do the job but you have much less control of where the solder goes.
The rosin runs with the solder so it goes every where.
Using a separate flux, you can apply the flux where you want the solder to go..more or less.

[vasily]

[QUOTE=Ralph ---
Using a separate flux, you can apply the flux where you want the solder to go..more or less.[/QUOTE]
That's right, except the separate solder MUST BE rosin core if you're soldering copper electrical joints. Acid core solder, which is used for plumbing, will corrode (that is, eat through) copper based joints.
If you tin the wire first you may get a better joint and not melt the plastic. Tinning means lightly pre-soldering the wire before soldering the joint,

[aeroengineer1]

This is an interesting thread. A couple of things here. First, it does not matter if the solder has flux in it or not (with a caveat that you use an external flux if it does not). In some areas it is advantageous, in other areas, I would much rather use a no clean flux and solid solder. Some fluxes can leave a bit of a mess to clean after using them. It gets rather annoying. Carb cleaner seems to work the best for cleaning most residues, but not all components are compatible with that. Once again, do not use acid flux for this operation as while it will work now, it gets trapped in the wires, and continues to corrode the joint and it can fail later.

As to soldering the connectors themselves and the soldering iron to do it. The wattage is not so much about the heat that the iron can put out, but how much of a thermal mass it can apply heat to and still maintain its proper temperature. Most often, soldering wires like this, it is best to have as many Watts as are practical. I have a 65W iron personally.

The next thing that is critical is that soldering is about heat transfer. There will be some videos that show "proper" soldering technique where you place the soldering iron on the backside of a joint without any solder, and then you apply the solder on the opposite side of the joint. This technique is likely to cause excessive heat to transfer into the part, and a poor soldering joint. If you are trying to do this on a PCB, you are likely to lift a pad.

The best way is to have the tip wetted. For a job with large gauge wire, having a large/broad tip is helpful, not small, sharp, pointy tip (something that comes down to fine point under .7mm) that is intended for soldering 0201 or QFN surface mount devices. Here is the process I use:

-Prep the soldering iron tip after you have set the heat (do this at the start of each soldering operation)
-Wipe the tip clean while hot
-Wet the tip with solder
-Be sure that the tip is fully clean and wets out (if not, repeat the process above)
-Tin the wire:
-Prep the soldering iron tip
-Apply flux to the tip of the wire if not using a fluxed cored solder (you can be pretty liberal with the flux, it generally does not hurt anything, only causes a bit of a mess to be cleaned later if too much is used)
-Place the iron to the wire that you want to solder
-Place the solder at the joint of the tip of the soldering iron and the wire
-As it starts to melt. move the solder to the tip of the wire and let the solder wick up to the heat
-Ensure that there is just enough solder to wet the tip of the wire with a light coat (you do not want too much solder to get soaked up in the wire itself as this can cause a stress and fatigue problem in the wire)
-Tin the connector:
-Prep the soldering iron tip
-Follow the same steps as above, but I tend to leave a little blob of solder on there to facilitate soldering
-Assemble the two components:
-Get a set of helping hands, or some other method to hold both the wire and the connector (needs something that can take the heat and is stable)
-Position the wire right above the solder blob in the connector (I like to preload the wire onto the solder blob a bit)
-Apply flux to the area to be soldered if not using a fluxed cored solder (same amount of liberalism in application can be used here)
-Prep the soldering iron tip
-Place the iron on both components you want to solder to preheat them (I find in this step that it once again helps to add a little bit of solder to the tip of the iron to help heat transfer, you do not need a lot, but a little molten solder makes greater surface area contact and will heat the joint quickly
-Add more solder if necessary to complete the soldering joint (you may not need to add more depending on how much you added in the tinning phase)
-You should have a nice fillet of solder on each side of the wire down to the connector, if it is a large blob, then you have too much

[aeroengineer1]

A quick side note, these style of connectors are a real pain to solder properly. I am not sure why the are so popular as they rely on the solder to form a mechanical joint, there is no through hole. It is an oversight on their part no doubt in an effort to reduce the cost. The best style to solder are ones that have a hole where the wire gets inserted, and then can be soldered in. It gives it a lot more area for dealing with the mechanical load that comes through that joint.

Another note, soldered joints are not always the best. Especially in high powered applications, automotive, and aerospace where there will be a lot of vibration, crimp connectors are preferred as they are more reliable. Many RF connections will be a mix of both. Marine can be a mix of both, or a combination of crimp and solder, though this does not always take care of the issues of corrosion.

There are "special" heat shrink tubing types that come with an adhesive/sealant to help in connections like this.

Also, never tin a wire that is going to be inserted into a screw terminal that is intended to take a lot of current. The solder likes to creep under heat and load. This increases the contact resistance, and can then cause fires. This has happened to a handful in the hobby 3D printer industry. It is bad, do not do it. What happens is that the solder begins to creep, the joint then becomes loose. Then the contact resistance goes up, causes oxidation, further increasing contact resistance. If there is enough current (actually localized power loss which is dominated by the current squared times the contact resistance), a fire can develop.

Adam

[bob_eissler]

The deans connector is going to get hot so have a fixture to hold it. Pre-tin the wire and deans terminals. Push the two together and apply heat with the soldering iron until they flow together.
Get one of these off of ebay:

Infinitely better tha a radioshack iron.

[pdoman]

Try this video:

https://www.youtube.com/watch?v=opMBIIB6l1M

[southern or]

Interesting thread so far. I use tamiya terminals myself but I wonder, would a soldering gun work? I prefer the gun over the iron for connectors because I'm not fighting the hole, wire, and iron all at the same time.