I'm working on my first EL wire project and I read lots of guides on how to solder the EL wire, all of them warning about cutting through the very thin radial wires that run outside of the phosphorous layer.
I tried a few times and it can be tricky, but I think I have a much easier way of doing it.
I'm not going to go into much detail about how the wire works or about the various layers that make up EL wire - I'm sure you will have read this elsewhere.
A couple of things that I found made this process easier (other than the usual EL wire tools) are:
- Solder flux pen - helps the solder take to the wire and copper tape
- Old computer CPU heatsink - by moving some of the fins closer together, it makes a perfect clamp for holding both wires while soldering, much better than croc clips because it doesn't damage the wire
- Sharp craft knife - I use a knife to cut through the EL wire outer coloured coating (but not for the clear inner coating)
Step 1: Cutting the Outer Coating
I need my solder joints to be as small as possible for my project, so I only cut of 7mm off the outer coating, but you can cut more if you want to.
Measure what you need to cut and gently roll the EL wire with the blade, using just enough pressure to cut through the outer coloured coating. If you cut slightly into the inner coating, this isn't a problem, so long as you don't go completely though both.
Step 2: 'Cutting' Through the Inner Coating
The trickiest part for most people is stripping the inner clear coating off the EL wire without cutting the thin wires that run down the outside of the phosphorous core. The first picture here shows those two wires under the clear coating.
To make this easier, I don't cut the coating, but melt it with the soldering iron!
Run the soldering iron around the inner coating where you want it cut it off. The soldering iron will quickly 'cut' through the coating and will be done in under a second. This does not appear to do any damage to the wires or phosphorous core and if far easier than using wire cutters.
Gently pull off the end of the coating and you should be left with something like I have in the third picture.
Remember, each time you do this, clean the soldering iron on a tip cleaner to get any plastic off the tip!
Step 3: Soldering the Thin Wire to the Copper Tape
This step is just the same as everyone else - cut off a thin strip of copper tape to wrap around the inner coating and solder the thin wires to.
I cut strips approximately 2mm x 7mm in size - it has worked well for all of my 2.3mm EL wire
Stick the copper strip to what remains of the inner coating and roll it round with your fingers. Then bend the two thin wires back onto the copper tape using the knife. By pushing wires into the corner of the copper tape and outer coating using the knife, you should trim the wire to the perfect length.
Clamp the EL wire between two fins of the heatsink (or whatever you use as a clamp) and apply a drop of flux to the tape. Solder the thin wires to the copper tape and this step is done!
Step 4: Strip the Inner Core
Using the knife, strip approximately 2-3mm of phosphorous from the end of the copper core.
To clean the last bits of phosphorous off, either keep scraping the knife over the wire or use some fine emery cloth.
You should have something like the second picture above,
Step 5: Soldering on the Electrical Wire
If you are using twin wire, part the wires and cut one slightly shorter so that they line up with the two copper contacts on your EL wire. Strip back 2mm of coating (wire strippers work fine for this!!). It's always a good idea to 'tin' the electrical wire before trying to solder it to the EL wire.
This step is where the heatsink is really useful! The heatsink that I am using (AMD stock heatsink) has a gap in the middle that is perfect for soldering. Wedge the EL wire in one side and the electrical wire in the other so that the EL wire core lines up with the shorter wire.
Solder them together and flip it over to solder the other wire.
Step 6: Finishing Off the Wire
My project requires my wires to be on the outside of a jacket that might get a little wet in use. To make the wires more waterproof, and to generally make a stronger join, I fill the heatshrink with shavings of glue from a heat gun.
Cut a length of heatshrink slightly longer than the join that you have made. Using your knife, cut some slivers of glue off a glue stick approximately the same length as the heatshrink. Feed the heatshrink over the end of the EL wire and down to the join. Just before you have covered the join, push the glue strips down the heatshrink and pull it completely over the join.
Using a heat gun, gently heat the heatshrink until it shrinks over the join. Remember, the heat gun can melt the EL wire coating so be gentle with it. Also, don't rush this step, you want the glue to melt before the heatshrink shrinks! If this has worked well, you should see some glue get squeezed out of the ends. Before it fully sets, you can tidy this up.
If you have a gluegun, you can try putting some glue straight onto the join and then pull the heatshrink over the top. It's easier than cutting the shavings, but difficult to get a thin enough layer of glue so the heatshrink will fit over.
Step 7: All Done!
I hope this has helped.
Good luck with your EL wire projects!!