Have you ever wondered what would happen if you boiled insulated copper wire? Boiling Wire To Salvage The Clean Copper
An old fellow once told me that if you boil copper wire, the rubber insulation surrounding the conductor will soften up and practically fall off. It sounded a little strange, but I decided to put the idea to the test.
The goal was simple: find out whether boiling wire could make stripping it easier than using a utility knife, a hook knife, or a conventional wire stripper.
Setting Up the Experiment
I put a large pot of water on a propane burner and brought it to a boil. A wood fire or campfire would probably make more sense for a larger-scale operation, but propane was quicker and more convenient for this test.
I gathered several types of copper wire, including:
- Three-conductor cable
- Service wire
- Older NMD cable
- Newer RW90 cable
- Older wire with cloth insulation
- Larger-gauge copper wire
I cut the samples into manageable lengths and dropped them into the boiling water.
After about ten minutes, it was time to see what happened.
The Insulation Definitely Softened
The first thing I noticed was that the wire had become much softer and more flexible.
Using tongs and insulated gloves, I pulled a piece of NMD cable out of the pot. The insulation was hot, obviously, but it had softened considerably.
Once I started the end with a knife and grabbed it with a pair of pliers, the insulation began pulling off much more easily than it normally would.
In fact, on some pieces, the outer insulation came off surprisingly well. Boiling Wire To Salvage The Clean Copper
The inner insulation also appeared to loosen up. It didn’t simply fall off by itself, but after the wire had been heated for longer, it became much easier to pull the insulation away from the copper conductors.
More Time in the Water Made a Difference
One of the biggest limitations was that the wire cooled down quickly once it was removed from the pot.
The insulation was noticeably easier to work with while it was still hot. After a minute or two, however, it began to stiffen again.
That meant the process worked best when the wire was kept hot and removed from the pot only when it was ready to be stripped.
With another piece of NMD cable, I stripped the end first and then tried pulling the insulation off while the wire was still hot.
This time, the insulation came off very easily.
The process was surprisingly satisfying. Once the end was started, the insulation pulled away from the copper with relatively little effort.
What About Larger Wire?
I also tried some larger, three-conductor cable.
The boiling water definitely made the cable more flexible, and the individual conductors were easier to remove from the outer jacket.
However, the insulation didn’t simply slide off with no effort. I still needed to start the cut with a hook knife before pulling the insulation away.
Once the cut was started, though, the job was noticeably easier than stripping the cable cold.
The older cable performed particularly well. After being boiled, the insulation became soft enough that stripping it with a hook knife was almost effortless.
That was probably the biggest advantage I saw during the experiment.
The Old Cloth-Insulated Wire Was Different
I also tested some much older wire with cloth insulation.
The results were mixed.
Some of the cloth insulation appeared to deteriorate or partially break down in the boiling water. However, it didn’t simply pull off the same way the newer rubber insulation did.
Once I got through the cloth covering, the wire was somewhat easier to strip, but the improvement wasn’t nearly as dramatic.
The old wire also appeared to be tin-plated copper, which made it an interesting sample to test.
So, Does Boiling Wire Actually Work?
Yes.
Boiling insulated copper wire does make it easier to strip.
The heat softens the insulation, making it more flexible and easier to cut and pull away from the copper. The effect was particularly noticeable with some of the older NMD cable.
However, it’s not a magic solution.
The insulation doesn’t simply fall off the wire. You still need to start the end, and you generally need pliers or another tool to pull the insulation away.
You also need to work quickly because the wire cools down quickly once it’s removed from the boiling water.
Is It Worth Doing?
That depends on how much wire you’re dealing with.
For a small amount of wire, conventional stripping methods may still be faster and more convenient.
For a large quantity of insulated copper wire, however, boiling could potentially make the process easier—especially if you have a large pot and a way to keep the water hot.
I think a large old pot over a wood fire or campfire would be more practical than burning propane for hours. If you were going to try this with a large amount of wire, keeping everything hot for 30 to 45 minutes might soften the insulation substantially more than the ten-minute test I performed.
Of course, safety is important. The wire and water are extremely hot, so proper insulated gloves, tongs, and pliers are essential. You also need to be careful when using knives and other stripping tools.
The Final Verdict
Boiling copper wire works—but it’s not perfect.
It definitely softens the insulation and can make stripping easier, particularly with certain types of older cable. In some cases, the difference was dramatic.
Whether it’s better than using a conventional wire stripper or a knife depends on the type and amount of wire you’re processing.
For a few pieces, probably not.
For a large pile of insulated copper wire, though, it might be worth experimenting with.
And, of course, stripping the wire is a much better option than burning it. Burning insulated wire can destroy the value of the material and leave you with contaminated copper and a mess to deal with.
So, there you have it: boiling wire really does make it easier to strip. Boiling Wire To Salvage The Clean Copper
Have you ever tried this method? Let me know what you think.
