Picture of Soldering iron tips from 6 AWG copper wire
Like the Jedi of the Old Republic who constructed their own lightsabers, each customized to the needs and style of its owner, many Instructables members build their own soldering irons, or at least heavily modify them. Last time I checked there were approximately one jillion instructables on the subject of homemade soldering irons.

A well constructed lightsaber is, according to Wookiepedia , a Jedi's "single perfect weapon that he or she would keep and use for a lifetime."

If only I had such a "perfect" soldering iron that would last forever! In my experience, soldering irons are reliable enough, but far from perfect. The part of the iron that is consumed the fastest is the tip. Soldering iron tips wear down, burn up, diffuse into the solder, or something... Honestly I'm not certain where the mass of the tip goes. Intuition, and the law of conservation of mass+energy, tell me it has to go somewhere. Everything goes somewhere. Anyway, all I know for sure is that I start out with a perfect well-tinned tip like a shiny sharpened pencil, and several hours later I end up with a crusty burned-looking stub. Hence the motivation to replace the tip every now and again.

The soldering iron tips created in this instructable are made starting from 6 AWG solid copper electrical wire, and these tips are are approximately 4 mm (5/32 inch) in diameter. In this instructable, I show how to make two styles of 4mm tip, the slidey-style, and the screwy-style.

Step 1 takes a closer look at these two styles of soldering iron tips.
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Jack A Lopez (author) 5 years ago
Also maybe worth mentioning:

I use a lamp dimmer to run my soldering iron at less than full power, with the belief that this makes the tips last longer.

Some instructables on the subject of lamp-dimmer style temperature throttling for soldering irons:

Works great if your stuck with a 40W iron.

Thanks very much for the #6 ground wire of copper. It works great, but do you know a way to make a conical point on the round wire? I make a 4-sided pointy tip with the Dremel, and then filed it conical. Is there an easy way? Mike

Jack A Lopez (author)  michael.neidich5 months ago

The first picture in Step 7 shows me grinding a cone shaped tip onto a short piece of copper wire. The piece of wire is held in the chuck of my drill press, and it is spinning, so pressing a file to it grinds away material in a way that is radially symmetric, kind of the same way a lathe works.

In this picture, I am holding a block of wood in one hand and a file in the other hand, with both pressing against the spinning copper. The reason for this technique is to sort of balance the forces on the copper work piece. Copper wire is soft. With just the file alone pressing on it, the wire has a tendency to bend somewhat. Essentially, the wood block prevents the copper wire from bending while it being ground down by the file.

Someone else was asking about this, in a comment below this one, and I drew some arrows on that picture, here,

to sort of indicate the direction of the pressing forces, since you can't "feel" force in pictures, because a picture is a visual thing.

eric m3 years ago
This is only a temp fix.

Copper/brass will be eaten by flux & solder. It's a pain to always tin a brass tip every 30 seconds.

Weller uses chrome on iron. It's superior.

Maybe you should find a steel or iron bit instead.
adamvan20005 years ago
OK, this may sound odd, but what about carbon rods, like the ones found in el-cheapo dollar store batteries? Will they conduct enough heat to be useful? I know they work great for those DIY cold-heat irons, but it just occurred to me how easy it'd be to make a new one of those. After all, to point them, all I do is use a pencil sharpener. May try this on my iron, just for kicks. ~adamvan2000
OK, first test says nope. All it did was smoke steadily, which I'm guessing was battery chemicals. Good thing for proper venting. I'm guessing that the carbon rods simply dissipate the heat too quickly for this to be an effective replacement for the regular or copper ones. ~adamvan2000
Jack A Lopez (author)  adamvan20005 years ago
This carbon rod idea seemed so zany, I thought I'd try it too. The carbon rod from a "heavy-duty" AA battery does happen to be just the right size (4mm diameter) to fit in my slidey-style soldering iron. Plus it was easy enough to file a conical point on to it. However, this new carbon tip doesn't conduct heat very well. I could barely get it to melt the solder.
Interesting concept, and at first blush it seems carbon would be much less susceptible to oxidizing than traditional nickle or chrome tips, or at least what oxidation does occur, it would dissipate as a gas (CO or CO2 depending upon conditions I believe) which the occasional tip shaping is a lot less bothersome than constant tip wiping, tinning, etc etc not to mention the terrible performance an oxidized tip provides . That property alone seems worthwhile enough to not give up on the concept just yet.
If the thermal conductivity is good but the problem is in thermal retention, it seems the idea is already halfway there. I don't have any graphite off hand of a substantial enough diameter, but maybe someone who does could give this idea a try;
Turn (or file) graphite to desired profile, then chuck it from the other end if on a lathe or work some vise voodoo on a drill press, use peck drilling to form a cavity. Next, using either copper or iron most likely (for their ability to retain heat) match to the profile of the cavity in the graphite, possibly adding some groves to accommodate for thermal expansion if cracking occurs with a tight match. Basically the carbon tip idea with a metallic core. If anyone tries it out I'd be interested to hear how it works out, or if someone has the graphite but dosnt have the tools hit me up and I'll turn a few for both of us if it works out.
Hey, we tried, right? It's funny, as the thermal conductivities of carbon and copper are 140 and 200, respectively, so they don't seem that far off. I seem to remember now reading somewhere that carbon dumps the heat too fast to be used this way, unless you're running a current through it and using it like a cold-heat soldering iron(one of my next projects). ~adamvan2000
unclelar5 years ago
The term used for cutting the threads,is simply "threading or to thread" an example ;would you thread this rod,or are you done threading that rod .Anyhow, good job on your instructable
Jack A Lopez (author)  unclelar5 years ago
So we tap threads into a hole with a tap, and we thread threads onto a rod with a die. God, I love the English language.
Exactly! Now You've got it.
crankyjew5 years ago
nice. i can see a drill clamped lightly in the vise as a good alternative for those of us without a drill press. also, copper electrical wire is usually dead soft. have you tried hardening the copper, and/or do you find it necessary?
Jack A Lopez (author)  crankyjew5 years ago
I don't do anything to harden the copper, and these homemade copper tips seem to work almost just like the factory made kind. Regarding the softness of copper, that reminded me of something. To keep from bending the piece while grinding, it can be helpful to have something pushing on both sides of it. This is the purpose of the piece of wood seen in some of the pictures.
gmoon5 years ago
There are some really good "tips" in this one... thanks!
jman 315 years ago
Very nice instructable! I just may use this method in the future. I've noticed however that all the tips I use are coated with some sort of silver substance. I have found that they last pretty good until I sharpen and get down to the raw copper, then they seem to burn up pretty quickly. Any idea what that is?
Jack A Lopez (author)  jman 315 years ago
MIght be iron or nickel, with a thin layer of tin on top. Honestly I don't know.

But I recently found this:
It's a 1996 patent for some kind of newfangled soldering iron tip. The "prior art" section mentions problems with soldering iron tip coatings, copper being soluble in tin at high temperatures, etc.

So maybe the legends of delicate tip coatings are true...
Thanks for the reply. I still think your idea is sound. As long as you keep a good point on it whenever you solder. Thanks for sharing!