Heat Shrink Tubing Sizes Explained

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Heat Shrink Tubing Sizes Explained

What size heat shrink should you use?  If you’re new to heat shrink tubing it can be a bit confusing at first.  Heat shrink has a couple different measurements that work hand-in-hand, and in this post, (and video), we want you understand what to look for to help you choose the right size heat shrink tubing.

Heat Shrink Tubing Sizes Explained

Watch the Video

How to Choose the Right Heat Shrink Tubing Size

Heat Shrink Tubing has multiple measurements that you need to know so you don’t make a mistake when picking out a size for your application.  The three main things to know are:

Inner Diameter

Shrink Ratio

Before & After Measurements

Inner Diameter is the actual measurement used to identify the size of heat shrink tubing.  It is the length of the tubing from one side to another (or diameter), measured from the inside of the tubing.  Heat Shrink tubing products are identified by the inner diameter measurement before the heat shrink is shrunk.

Diameter of a Circle

Shrink Ratio refers to how much something shrinks and is a before & after measurement, (or ratio).  A 2:1, (said “2 to 1”), ratio for example, would start 2 times larger than what it can shrink down to.  Some common shrink ratios are 2:1, 3:1, 4:1, and 6:1.

Heat Shrink Tubing Shrink Ratio Comparison

Before & After Measurements are exactly what they sound like: measurements of the heat shrink product before and after it is shrunk.

To make sure you purchase the correct size of tubing, you really need to mix and match knowledge from these three points, so let’s explore that quickly.  As we do that, we’ll explore in a little more depth how knowing a bit about each of the above three topics proves helpful in choosing the right sized heat shrink tubing.

Inner Diameter

As stated above, inner diameter is what we use to identify the actual size of a tube.  Let’s say you have a hose you want to cover with heat shrink and the hose is about ¾ of an inch, (or 0.75 inches).  You could quickly go look for ¾ inch heat shrink, but that would be a mistake.  What you really want is heat shrink that starts larger than ¾ inch but ultimately shrinks down a bit smaller than ¾ inch.  The reason for this is that you want the heat shrink to easily fit over what you are trying to protect to begin with, and to still shrink down tight to give you the performance from the heat shrink you need.  So, in the case of a the ¾ hose, let’s choose something a bit larger as our starting point and go with a 1-inch heat shrink tubing.

Shrink Ratio

Next, Shrink Ratio.  How far do you need the heat shrink to shrink?  It’s important to remember that shrink ratio is a ratio and not a size.  Most heat shrink tubing sellers or manufacturers, (ourselves included), will typically categorize heat shrink by shrink ratio.  For example, on our site, we have categorized our heat shrink products into 2:1, (said “2 to 1”), 3:1, 4:1, and 6:1 heat shrink tubing.  So, going back to our 1-inch heat shrink tubing example, if we were to get 1 inch tubing in all these shrink ratios, they would all shrink down to very different sizes, as shown in the table below.

Shrink Ratio

Before Size

After Size

2:1

1 inch

0.5 inch

3:1

1 inch

0.33 inch

4:1

1 inch

0.25 inch

6:1

1 inch

0.167 inch

Going back to the example of a hose, we could likely use a 2:1 heat shrink tubing, sized at 1 inch, that will easily fit over the hose to begin with, but shrinks down smaller than ¾ of an inch.  In truth, we could use any of the heat shrink tubing listed in the table above, but since the 2:1 works the others would just be over doing it.

Before & After Measurements

You probably already noticed, but just above we used a table that showed us some Before & After Measurements.  Whenever you are shopping for heat shrink tubing, you’ll find that the tubing has these before and after measurements available, often found in the tubing specifications, or in a data/spec sheet.  Looking at these measurements is the best way to make sure the tubing will fit over what you are trying to protect before shrinking, while still shrinking down tight once it has been shrunk.

We should mention, the way the data is listed in the table above is not how you will normally find the before and after measurements listed when you are researching heat shrink products.  Typically, you can find the before and after measurements in a table in the specifications of the heat shrink or on a data sheet.  However, they may not even use the terms “before” and “after.”  On our heat shrink products, for example, we use the more technically correct terms of “supplied” and “recovered,” which essentially are the same as “before” and “after” shrinking.

You also won’t normally see multiple shrink ratios listed alongside one another as a comparison.  What’s much more typical is to see all the sizes that one specific product is available in, alongside the sizes that those sizes shrink down to, as shown in the table below.

Gamma 2:1 Polyolefin Heat Shrink Tubing

Sizing Before (Supplied)

Sizing After (Recovered)

Tubing Size (inches)

mm

inches

mm

inches

1/4

6.4

0.25

3.2

0.125

3/8

9.5

0.37

4.8

0.187

1/2

12.7

0.5

6.4

0.25

3/4

19.1

0.75

9.5

0.375

1

25.4

1

12.7

0.5

1-1/4

31.8

1.25

15.9

0.625

1-1/2

38.1

1.5

19.1

0.75

2

50.8

2

25.4

1

Before and After measurements will give you the best data available so you can make sure you’re choosing the right size heat shrink tubing.  It’s key however, to make sure you are getting an accurate measurement of what you are trying to protect, or all the information above could be considered nearly useless to you.

How To Get An Accurate Measurement

Almost always, heat shrink tubing is used to protect some other type of tubing, like a wire, cable, or hose.  Assuming you are trying to put heat shrink onto some other kind of tube, you’re going to need to get an accurate measurement of that tube.  Just as heat shrink tubing uses diameter for its measurement, you’re going to want to measure the diameter of what it is you are trying to protect, (in this case, the outer diameter).  You can do this with a ruler or measuring tape, but the most accurate way of doing it is with a caliper, (shown below).

Measuring with Calipers
Measuring with Calipers

Calipers are incredibly accurate and make measuring things like diameters much easier.  You can also find calipers fairly easily and inexpensively, (around $10-15), although there are models that go much higher.

Whatever tool you use, you need to be thinking about the before and after measurement of heat shrink tubing when you measure. Does the heat shrink need to fit over something large when you first move it into place?  And how small does it have to shrink down to once moved into place?  For example, if you have a cable you want to put heat shrink onto, does the cable have a connector on the end that the heat shrink must fit over first?  If so, the heat shrink might need to be larger than you first anticipate and could even result in you needing to opt for a higher shrink ratio tubing.  You don’t want the heat shrink to be too tight and difficult to move into place to begin with, so give yourself breathing room.  And, as mentioned previously, make sure the heat shrink tubing shrinks down a bit smaller than whatever you are placing it onto.

So, measure the largest part you need the heat shrink to fit over, and then the smallest part that it needs to also shrink onto.  And try to get those measurements as accurate as you can.  Once you have accurate measurements, you’ll be able to, (with the information above), make sure you are choosing the right sized heat shrink tubing.

What If You Can’t Use Heat Shrink Tubing?

Sometimes you might have something you are trying to protect that you just can’t fit heat shrink tubing around.  We’ve also had customers who cannot utilize heat guns or blow torches in certain environments, and they need an alternative option.  Luckily, we offer solutions to help work around these issues.

If you have something that is an odd size or it is already installed and you can’t easily slip heat shrink tubing over it, then you might want to look at our FIX-105 tape, a heat shrinkable tape.  Heat shrink tape gives you the benefits of heat shrink tubing without it having to be an actual tube.  You wrap it and shrink it and don’t have to worry about sizing issues.

You could also use our Self-Amalgamating Tape, or “Magic Tape” in many scenarios.  We have customers use it for weatherproofing purposes all the time, so it really depends on your needs.

In other scenarios, we’ve had customers tell us they cannot use heat guns, blow torches, etc., in certain environments, but they still want a protective tubing.  Our Cold Shrink Tubing is perfect in these environments/scenarios, as it does not require any heat, or even additional tools, to be installed.

Conclusion

Hopefully you feel like you now have a better understanding of how to choose the right sized heat shrink tubing for your needs.  Is there something we missed?  Have any additional questions?  Let us know in the comments below!

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2022 Wrap Up

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2022 Wrap Up

The holiday season is upon us, once again, which means it’s time for the Gamma Electronics’ yearly “Wrap-up.”  We have much to be grateful for this year, (as we do every year), and before going any further, I want to make sure we thank our customers and partners.  We love working with each of you and look forward to building on our working-relationships well into the future.  Thank you for your continued support.

We also like to spend a bit of time each holiday season looking back at all that has transpired in the past year.  2022 had its share of news that is worthy of reflecting upon.

Merry Christmas & Happy Holidays from Gamma Electronics

New Products

In 2022 we released several exciting, new products.  We have continued our quest to provide quality weatherproofing for coaxial cables and connections of all sizes, and early in 2022 we released Weatherproof Boots for LMR195 coaxial cables, in addition to Weatherproof Boots and Cold Shrink Tubing that work with SMA connections.  We continue to find ways to weatherproof even the smallest coax connections up to IP68 standards, (and often higher).

Beyond Coaxial Weatherproofing, in 2022 we introduced our first products specific to the DAS, (Distributed Antenna Systems), market.  This past summer we released our revolutionary, Multi-Cable Stripping Tool, which makes it possible to strip multiple types of cable, (including CommScope and RFS), with a single tool.  We also introduced RF Compression Connectors alongside the Multi-Cable Stripping Tool, as these connectors will also work with multiple types of cables. These two new products have made it easier than ever for contractors to work with coaxial cables from different manufacturers, while improving efficiency and reducing costs.

New Training Content

In addition to new products, we also continue to provide content designed to help answer questions and assist our customers in achieving the best possible experience with Gamma products.  This past year we released content about using heat shrink tubing, heat shrink tape, cold shrink tubing, and how to weatherproof coaxial connections.  We also tried to tackle difficult questions about wildfire safety and heat shrink tubing.

The goal for our team at Gamma Electronics’ is not to just make great products but is also to provide content that will help our customers and partners feel confident not just in our products, but in how to correctly use our products to ensure best results.  Please feel free to let us know in the comments below if there is content we can provide that will help you better understand our products and/or how to use them.

2022 Holiday Hours

As a quick sidenote for the 2022 Holiday Season, our offices will be closed the week of December 26 through December 30, with our team returning to the office on January 2, 2023.    Being that our office is closed on weekends, we ask that if you need anything from our team before the end of the year, please make sure to reach out to the appropriate Gamma contact before Friday, December 23.

Looking Ahead to 2023

While 2022 kept us plenty busy we are even more excited for all that 2023 will bring.  As mentioned previously, we have only begun building out our DAS product line, and we will have exciting updates for this product line to come in early 2023.  But while we’re excited about our DAS lineup, that is not all that we have planned for 2023.  So please, keep a lookout in your inbox, on our blog, or on social media for updates in the months to come.

Merry Christmas & Happy Holidays

To “wrap things up,” I would like to again say thank you on behalf of the entire Gamma Electronics team.  We know that you have choices available to you in who you do business with, and we are grateful every time you choose to work with us.  Merry Christmas and Happy Holidays from the Gamma Electronics team.

Best Wishes,

Cameron Lanier

Director of Marketing and Media Communications

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How to Use Heat Shrink Tape

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How to Use Heat Shrink Tape

Heat shrinkable tape is a fantastic tool that makes it easier than ever to protect something, like wires or a wire harness, with heat shrink tubing.

Heat shrink tape gets around the limitations of heat shrink tubing, which typically would need to have wires or a wire harness run through the tubing before the tubing is shrunk down. If you have wires, a hose, a wire harness, etc. that has already been installed, it would be difficult and in some cases impossible to get heat shrink tubing around or over it.  In these situations, heat shrink tape can easily wrap around what you are trying to protect, and then be shrunk down.

How to Use Heat Shrink Tape

Below we’ve listed step-by-step instructions on how to install our heat shrinkable tape, in addition to a video which also goes through the process in a little more than 2 minutes.

Watch Our Install Video

FIX-105 Heat Shrinkable Tape

Our FIX-105 Tape is a heat shrinkable tape that is available in different widths, lengths, and colors, in addition to having a heavy wall option.

Adhesive Lined Cross-Linked Heat Shrinkable Tape

1 –  Wear Gloves

Wear Gloves

When using any type of heat shrink tubing product you should always wear gloves to protect yourself from the heat coming off of either a heat gun, or in some cases, a blow-torch.

2 –  Cut the Heat Shrink Tape

Wear Gloves

Unroll the tape and cut to your desired length using an everyday pair of scissors.

3 –  Heat One End of the Tape Until it Curls

Use a heat gun to heat one end of the heat shrink tape until that end curls.  This makes it easy for the curled end to be applied to whatever you are wrapping the tape around.

If you prefer, you can also use a zip tie to hold the tape end in place.  You simply want to make sure that the tape will hold its position during the heat shrinking process.

Note: Gamma FIX-105 tape needs to be heated to a temperature of about 200° F in order to shrink, for this reason we do not recommend using a hair dryer, as hair or blow dryers, at their best, only tend to heat up to about 140° F.

4 –  Apply Curled End of Tape

Take the heated/curled end of the heat shrinkable tape and apply it to what you desire to wrap the tape  over.  The heated end should stick, making the next step easier.

5 –  Wrap the Tape with Each Wrap Overlapping Itself

Wrap the tape around the cables/wires, (or whatever it is you are wanting to protect), making sure to overlap the heat shrink tape over itself so that once it shrinks, it adheres to itself.

6 –  Place a Zip Tie Over the End of the Heat Shrink Tape

Wrap the tape around the cables/wires, (or whatever it is you are wanting to protect), making sure to overlap the heat shrink tape over itself so that once it shrinks, it adheres to itself.

7 –  Use a Heat Gun to Shrink the Heat Shrinkable Tape

Use a heat gun to shrink the heat shrinkable tape.  Make sure to move the heat around the heat shrink tape, heating it as evenly as possible.

8 –  Remove the Cable Tie

Once the heat shrink tape has shrunk down small enough or it is completely shrunk down and in place, move the zip tie off of the tape, and completely remove it by cutting it with a pair of scissors.  Make sure you still have gloves on given that the heat shrink tape will be hot if you happen to touch it, and the zip tie will likely be hot as well.

9 –  Installation is Complete

Wear Gloves

Let the tape cool and installation is complete.

Purchase Heat Shrinkable Tape

Our FIX-105 Tape is a heat shrinkable tape that is available in different widths, lengths, and colors, in addition to having a heavy wall option.

Gamma Electronics FIX-105 Tape

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How to Use Heat Shrink Tubing

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How to Use Heat Shrink Tubing

You may not be fully aware but heat shrink tubing is a part of your daily life.  Heat shrink tubing is used on products ranging from phone cords to motor homes to airplanes and beyond.  Heat shrink tubing isn’t very difficult to install but can be a little intimidating if you’ve never done it before.  Below are some instructions to get you started with using heat shrink tubing.

We also have a post, “What is Heat Shrink Tubing?” where we answer a number of frequently asked questions for those new to heat shrink tubing.

How to Use Heat Shrink

Watch our video on how to use and/or install heat shrink tubing, or check out the step-by-step instructions below.

Watch Our Video

Heat Shrink Tubing

Heat Shrink Tubing comes in a variety of sizes and shrink ratios.  There are heat shrink variations made for some of the most unique circumstances, like gas and diesel resistant heat shrink, UV resistant heat shrink, or even heat shrinkable tape.  You can learn more about our many heat shrink offerings by clicking here, or on the button below.

Adhesive Lined Cross-Linked Heat Shrinkable Tape

How to Install Heat Shrink Tubing

Step-by-Step Instructions

1 – Identify Where You Need to Install the Heat Shrink Tubing

The first thing to do is identify where you want to install your heat shrink tubing.  In this example we are going to install heat shrink over an iPhone charging cable that has seen better days.  The cable has lost a portion of its cable jacket making the wire(s) underneath vulnerable.  Exposed wires like these can result in cables/wires not working, and in some cases exposed electrical wires are very hazardous.  Heat shrink tubing is a great way to cover the cable and resolve these issues.

2 – Choose the Right Heat Shrink Tubing for Your Needs

If you’re new to heat shrink tubing, choosing the right tubing can be a bit tricky.  Heat shrink tubing comes in many different sizes, different shrink ratios, and there are many different types that offer unique characteristics.  The first thing to know is that heat shrink tubing sizes are listed in a before shrinking size.  So measure what it is you need the heat shrink to fit over and make sure you choose a size larger a little larger than that. To make sure our heat shrink tubing would fit over the iPhone cable and the connector at the end of the cable, we chose a 3/8 of an inch heat shrink tubing for this example.

The next thing to know, is the shrink ratio.  Shrink ratio measures the difference between the size of the tubing before and after it shrinks.  For example, we chose to use a 3 to 1, (usually written in ratio form as 3:1), heat shrink tubing on the iPhone cord, which means the tubing starts 3 times larger than what it shrinks down to.    We offer heat shrink tubing in 2:1, 3:1, 4:1, and 6:1 shrink ratios.

The last thing to be aware of when selecting your heat shrink tubing are any additional special qualities or characteristics that you might need.  For example, there are diesel and fluid resistant types of heat shrink out there, as well as heat shrink that is UV resistant.  For the iPhone cord we chose to use an adhesive lined heat shrink tubing that will make sure the heat shrink glues itself in place.

3 – Measure your Heat Shrink Tubing

Make sure to measure your heat shrink tubing so that it comfortably covers the exposed wire, or whatever vulnerability it is you want to cover.  It doesn’t have to be an exact science but you want the tubing to easily extend beyond whatever it is you want to protect.

You can mark where you would like to cut the heat shrink with a pencil to make things easier.

4 – Cut the Heat Shrink Tubing

Once you’ve measured the heat shrink tubing simply cut the tubing. The vast majority of heat shrink tubing can be cut with a normal, everyday pair of scissors.  

5 – Cover the Exposed Wire (Vulnerability) with the Heat Shrink Tubing

Once you’ve cut the heat shrink tubing, take the cut piece and place it on the cable in preparation to shrink it into place.

6 –  Turn on Heat Gun

We highly recommend using a heat gun for installing heat shrink as heat guns reach the necessary temperatures for installing heat shrink in the safest way possible.  However, heat shrink tubing can be installed using a lighter, blow torches, or in some cases even a hair dryer.

7 –  Place Cable with Heat Shrink Tubing Over the Heat

It’s time to start shrinking the heat shrink.  Take the cable with the heat shrink on it and put it over the heat gun, or whatever your heat source may be.  If there is enough heat the heat shrink should start shrinking almost immediately.

8 –  Rotate & Move the Heat Shrink Tubing (or Heat Source)

In this example the heat gun is stationary, so make sure that you keep moving the heat shrink tubing so that it shrinks evenly and completely.  You also want to make sure that you don’t keep the heat in one place on the heat shrink for too long, as it can burn through the heat shrink and potentially damage the cable underneath.

In many installation cases, the heat shrink might be stationary while the heat gun/heat source is what is moving.  Regardless of the methodology, make sure that the heat source does not stay in one place for too long and that the heat gets all around the tubing for an even and complete installation.

9 –  Installation is Complete

You will be able to see that the heat shrink has conformed to what is underneath it, in this case the cable and connection.  Make sure you don’t touch the heat shrink as it will still be hot. Let it cool and you are done.

C

Heat Shrink Tubing

Heat Shrink Tubing comes in a variety of sizes and shrink ratios.  There are heat shrink variations made for some of the most unique circumstances, like gas and diesel resistant heat shrink, UV resistant heat shrink, or even heat shrinkable tape.  You can learn more about our many heat shrink offerings by clicking here, or on the button below.

Adhesive Lined Cross-Linked Heat Shrinkable Tape

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Prevent Wildfires with Heat Shrink Alternatives

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Prevent Wildfires with Heat Shrink Alternatives

Wildfires are a growing problem.  Want proof?  The National Interagency Fire Center has been keeping statistics on wildfires since 1983.  Since that time wildfires have increased by 223%.  In more recent history, wildfires increased between 2019 and 2021 by 17%.  Over 10 million acres were burned by wildfires in 2020 alone.1

As the leading provider of weatherproofing products for the telecommunications industry we are accustomed to talking about products that will be used on cell phone towers, on buildings and rooftops, etc.  What has surprised us however, (initially anyway), is that in recent months more companies have started looking at heat shrink alternatives.  The primary reason?  Wildfires.

Prevent Wildfires with Heat Shrink Alternatives

The more we looked into the issue, the more sense it made to get away from heat shrink in outdoor applications.  Nearly 85% of wildfires are started by humans according to the U.S. Forest Service Research Data Archive.2  The National Park Service states that most of these fires “result from campfires left unattended, the burning of debris, equipment use and malfunctions, negligently discarded cigarettes, and intentional acts of arson.”3

So, how do humans do a better job of preventing these devastating wildfires?  Issues like unattended campfires, the burning of debris, and negligently discarded cigarettes are largely matters of education, (just ask Smokey Bear).  Arson must obviously be dealt with as a criminal issue.  Equipment use and malfunctions however, present glaring issues that can be handled better.  And unfortunately, equipment use and malfunctions have resulted in some of the largest wildfires in United States history.4

%

Increase in Wildfires since 1983 in the United States

%

Increase in Wildfires from 2019 to 2021 in US

%

Percentage of wildfires in the US caused by humans.

Unfortunately, California is a prime example of wildfires resulting from equipment use and malfunctions.  Just last year, the Dixie Fire burned nearly 1 million acres and over 1,300 structures, including the entire town of Greenville, CA.  Investigations now show that a tree that should have been removed, fell across a powerline operated by Pacific Gas & Electric (PG&E), sparking the fire.  However, the powerline in question was part of a 10 mile stretch set to be buried5, a move which would have prevented the fire altogether.

The Dixie Fire adds to PG&E’s already poor record with wildfires over the last several years.  In 2020, PG&E pleaded guilty to 84 counts of involuntary manslaughter for having started California’s massive Camp Fire in 2018  Former PG&E CEO and President, Bill Johnson made PG&E’s fault in the matter plain when he said, “Our equipment started that fire.”6.  Butte County District Attorney Mike Ramsey, who put together a report about the 2018 Camp Fire, stated that PG&E was guilty of “reckless behavior,” and that PG&E’s use of badly outdated technology was “evidence of absolute indifference.”7

Some critics will point out that California’s forest management also plays a role in these wildfires, which is a valid point.  California’s lack of forest management creates a massive amount of fuel for these fires, with experts estimating that California needs to improve its forest management efforts to “around ten times its current level.”8

Business Ramifications

How well a state deals with forest management issues however, is outside of a company’s control.  What should matter to companies are the liability issues.  PG&E has faced “tens of billions of dollars in potential fire liabilities,” leading them to file for bankruptcy in 2019.  PG&E has since restructured their debts, agreeing “to pay $25.5 billion in fire-related claims.”9  Just last month, PG&E agreed to another $55 million dollar settlement in relation to the Dixie and Kincaide Fires.10

Wildfires can be absolutely devastating, destroying property, livelihoods, and in some cases, even human lives. That should be reason enough for businesses to take as many preventative measures as possible.  From a purely financial perspective however, the cost of upgrading to better, wildfire preventative equipment and practices surely costs less than the millions and potentially billions of dollars lost to wildfire related claims.

Just ask PG&E.  Shortly after the Dixie Fire started, the company announced a plan to bury 10,000 miles of power lines so they won’t spark wildfires.  The plan had apparently been in the works but was expedited by several months after the start of the Dixie Fire.  As PG&E’s CEO, Patricia “Patti” Pope said to reporters on the day of the announcement, “It’s too expensive not to do it.  Lives are on the line.” 11

The Heat Shrink Problem

All this leads us back to heat shrink tubing.  An easy, wildfire preventative measure that many companies could start making right away is to stop using heat shrink tubing in outdoor applications.  More specifically, if the heat shrink is being installed outdoors than it should be replaced with an alternative product that does not require a blow torch or heat gun to install.  California is already urging companies to make this standard practice and it’s completely understandable as to why.

Heat shrink tubing is typically used in these outdoor applications as a protective measure.  To make sure that electrical connections keep out water and weather in general, heat shrink is installed over mated connections.  The heat shrink adds a protective layer to ensure the connection is not interfered with, keeps water out, stays mated, etc.

As a heat shrink tubing company, we don’t like to see heat shrink tubing being phased out, but from a safety perspective it makes too much sense.  This is especially true when you consider the U.S. Department of the Interior’s “10 Tips to Prevent Wildfires.” Number 8 on that list states to “Keep Sparks Away from Dry Vegetation,” and to “make sure you never operate equipment that produces sparks near dry vegetation.”12  Using a blow torch or heat gun is quite literally doing the opposite from what the Department of the Interior recommends.  Using a blow torch or heat gun in such scenarios could easily be considered reckless.

All of this may seem obvious, but unfortunately, heat shrink is still seeing regular use in compromising situations.  For example, there are cable boxes all over the United States in which heat shrink is being utilized.  These cable boxes are outdoors and can be found frequently, very frequently.  You have more than likely seen some of these boxes, (many of them are green), which house cables and connections that contractors need access to.  By the nature of their locations these boxes are often found around dry vegetation.  Heat shrink is being installed via blowtorches or heat guns inside these boxes regularly.

For those who might be wondering, yes, blowtorches are quite often used instead of heat guns.  The reason being, heat gun batteries are not known to last very long and having multiple batteries can add up, (in terms of cost).  It’s far more cost effective to have a blowtorch, as propane is far cheaper than batteries for a heat gun and the blowtorch is going to give you much more “bang for buck.”  What this really means is that blowtorches, or open flames, are regularly being used around dry vegetation.

In truth it’s a miracle more fires have not been started by means of heat shrink installation.  That’s a credit to the contractors using these tools.  However, if you were to speak to these contractors, (as we have), they too prefer getting away from the use of heat shrink tubing.  After all, the contractors understand it only takes one bad heat shrink installation to start a fire and they don’t want to bear the responsibility for a fire.

Why Does Heat Shrink Continue to be Used?

The simple answer is cost.  Heat shrink tubing alternatives admittedly cost more and there are a lot of connections out there which do need to be covered and protected.  It’s understandable that companies are trying to save money, but that savings quickly disappears as soon as a fire breaks out.  The larger the fire the more foolish that decision looks.

Looking at Heat Shrink Alternatives

As stated previously, Gamma Electronics is a heat shrink tubing company.  We started out as a heat shrink tubing company and we continue to be a leading heat shrink supplier for numerous industries.  

Cold Shrink Tubing

In outdoor applications like those described above however, we strongly encourage customers to look at an alternative like cold shrink tubing, which requires no heat to be installed. In fact, cold shrink does not require any tools for installation, and it can be installed in seconds.  Cold Shrink tubing is the most similar product to heat shrink tubing in terms of functionality, and has become the product that our customers have turned to when heat shrink isn’t an option.  Even better, we have already manufactured cold shrink solutions sized for the cables and connections in the aforementioned, green cable boxes seen above.

Slide Locks & RF Weatherproof Boots

Of course, there are other alternatives, including slide locks, (a type of clam shell enclosure), and silicone rubber boots.  These can be very specific however in terms of needing to match both a cable and a connector in order to provide a watertight seal.

Magic Tape (Self-Amalgamating Tape)

Another alternative is Magic Tape, (often referred to as self-amalgamating tape).  Magic Tape is a cut-to-size solution that could see implementation right away.  Magic tape adheres to itself and does not require heat or adhesive to create a watertight seal.

Conclusion

Companies, and more specifically utiltiy and cable companies, may very well continue to use heat shrink tubing outdoors, but it only takes one fire before it becomes obvious that doing so was a bad idea.  Many companies love the low cost of heat shrink, but when you consider the literal billions of dollars that can quickly accrue from fire-related claims, is it worth it?  Using heat shrink in outdoor scenarios is reckless.  Heat shrink alternatives might be more expensive, but they will only save you money and headaches in the end.

Citations

1 “Wildfires and Acres,” National Interagency Fire Center, accessed May 10, 2022, https://www.nifc.gov/fire-information/statistics/wildfires.

2Karen C. Short, “Spatial wildfire occurrence data for the United States, 1992-2018” United States Department of Agriculture, accessed May 10, 2022, https://www.fs.usda.gov/rds/archive/Catalog/RDS-2013-0009.5.

3 “Wildfire Causes and Evaluations,” National Park Service, accessed May 10, 2022, https://www.nps.gov/articles/wildfire-causes-and-evaluation.htm

4 “Worst Wildfires in U.S. History,” Earth.org, accessed May 10, 2022, https://earth.org/worst-wildfires-in-us-history/

5 “Power line suspected in Dixie Fire was set to be buried underground in safety move,” LATimes.com, accessed May 10, 2022, https://www.latimes.com/california/story/2021-08-10/pge-power-line-dixie-fire-scheduled-to-be-buried-underground.

6 Phil Helsel, “PG&E pleads guilty to 84 counts of manslaughter in devastating Camp Fire,” NBC News, accessed May 10, 2022, https://www.nbcnews.com/news/us-news/pg-e-pleads-guilty-84-counts-manslaughter-devastating-camp-fire-n1231256

7 Colby Bermel, “PG&E showed ‘absolute indifference’ ahead of Camp Fire, DA says,” Politico.com, accessed August 12, 2021, https://www.politico.com/states/california/story/2020/06/16/pg-e-showed-absolute-indifference-ahead-of-camp-fire-da-says-1293295

8 Bill Chappell, “The Dixie Fire Is The 2nd Largest In California History And Is Only 21% Contained” NPR.org, accessed August 12, 2021, https://www.npr.org/2021/08/09/1026078606/dixie-fire-california-only-21-percent-contained.

9 Carolyn Cole, “Meet the New PG&E, it Looks A Lot Like the Old PG&E” LATimes.com, accessed August 12, 2021, https://www.latimes.com/environment/story/2020-06-17/pge-bankruptcy-new-pge-looks-like-old-pge.

10 Olga R. Rodriguez, “PG&E to pay $55 million for two massive California wildfires,” PBS.org, accessed May 10, 2022, https://www.pbs.org/newshour/nation/pge-to-pay-55-million-for-two-massive-california-wildfires

11“PG&E Will Bury 10,000 Miles of Power Lines So They Don’t Spark Wildfires,” NPR.org, accessed May 10, 2022, https://www.npr.org/2021/07/21/1019058925/utility-bury-power-lines-wildfires-california

12“10 Tips to Prevent Wildfires” U.S. Department of the Interior, accessed May 10, 2022, https://www.doi.gov/blog/10-tips-prevent-wildfires

Additional References

Colby Bermel, “Dixie Fire becomes largest single wildfire in California history,” Politico.com, accessed August 12, 2021, https://www.politico.com/states/california/story/2021/08/06/dixie-fire-becomes-largest-single-wildfire-in-california-history-1389651.

Ivan Penn & Peter Eavis, “PG&E Pleads Guilty to 84 Counts of Manslaughter in Camp Fire Case,” NYTimes.com, accessed August 12, 2021, https://www.nytimes.com/2020/06/16/business/energy-environment/pge-camp-fire-california-wildfires.html

Eric Ting, “Everything we know about PG&E’s link to California’s raging Dixie Fire,” SFGate.com, accessed August 12, 2021, https://www.sfgate.com/california-wildfires/article/Dixie-Fire-PG-E-power-lines-tree-what-started-burn-16377413.php

Molly Taft, “The Dixie Fire Is Now the Largest Single Wildfire in California History,” Gizmodo, accessed August 12, 2021, https://gizmodo.com/the-dixie-fire-is-now-the-largest-single-wildfire-in-ca-1847459144

“PG&E power line that possibly sparked massive Dixie Fire was set to be buried in safety move,” KTLA.com, accessed August 12, 2021, https://ktla.com/news/california/pge-power-line-that-possibly-sparked-massive-dixie-fire-was-set-to-be-buried-in-safety-move/

Lena Borrelli, “U.S. Wildfire Statistics 2022, accessed May 10, 2022, https://www.bankrate.com/insurance/homeowners-insurance/wildfire-statistics/

“Top 20 Largest California Wildfires,” Fire.CA.gov, accessed May 10, 2022, https://www.fire.ca.gov/media/4jandlhh/top20_acres.pdf

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How to Weatherproof Coaxial Connectors

Gamma Electronics Blog

How to Weatherproof Coaxial Connectors

What Are Your Coaxial Connector Weatherproofing Options and What You Should Know About Each of Them

Coaxial, (or coax), connections are vital to modern day infrastructure.  Coaxial connections see heavy use in the world of telecommunications, (i.e. cell phone service), but they are also frequently used by internet service providers, radio and television broadcasting companies, and more.  With such frequent use, it’s important to ensure that coaxial connections are properly protected and maintained to ensure optimal performance.

How to Weatherproof Coax Connectors

More often than not coaxial connections are found outdoors, exposed to the elements.  This is why weatherproofing coaxial connections has become a priority for many companies in recent years, as better weatherproofing results in more reliable connectivity.

This leads to the question, how do you successfully weatherproof coax connectors?

Coaxial Connector Weatherproofing Options

There are numerous weatherproofing solutions for coaxial connectors, each of them being beneficial for different scenarios.    6 of the most popular RF weatherproofing options are:

Below we take a quick look at the pro’s and con’s of each of these types of coax connector weatherproofing.

Cold Shrink Tubing is a rubber sleeve that slides directly over the coax connector you are trying to protect.  The tubing has an inner plastic core that is holding it in place.  The inner plastic core is perforated so it can be pulled free.  As the plastic core is removed the cold shrink instantly shrinks down over the coax connector.

Cold shrink tubing can be installed in seconds and is quite possibly the best form of coax connector weatherproofing available, (depending on your needs and the circumstances).  It is a true “set it and forget it” form of weatherproofing that creates a watertight seal over connections and has incredible weather resistant capabilities, (including extreme temperatures).

There are a couple things to know about cold shrink tubing however that may not make it ideal weatherproofing for every situation.  First, cold shrink tubing is not a “one size fits all” solution.  You cannot buy one size of cold shrink tubing and expect it to simply work for all of your connections.  A larger size cold shrink tube may not shrink down small enough for a smaller connector.  This is why we created numerous cold shrink tubing sizes that we have tested and perfectly matched to different coax connector and cable combos, as seen below.

There are two other things you should know about cold shrink tubing before you buy.  First, cold shrink is not reusable.  Once installed, it is meant to stay on the cable.  It has no adhesive, so removal is fairly easy, but, again, it is meant to be a “set it and forget it” option.

Secondly, there are two types of cold shrink tubing, Silicone and EPDM, and you should know which one you need before you buy.  For the purpose of weatherproofing coax connectors you will almost always want silicone.  Silicone shrinks down smaller and tighter than EPDM and is also able to endure more extreme temperatures.  EPDM is better suited for use in environments where abrasion is more likely.  You can read more about EPDM vs Silicone cold shrink here.

SDL-1A-125 Cold Shrink before and after

Our silicone cold shrink tubing is our most popular form of coaxial connector weatherproofing.  Customers like AT&T use it because it means less return trips to towers and it typically only needs replacement when an antenna, radio, etc. needs replacement.  Our cold shrink tubing has become an industry standard as it has helped to massively reduce maintenance costs for companies using it for coax weatherproofing.

Slide Locks have an outer plastic shell and an inner silicone gel that wraps itself around the connection to create a watertight seal.  The outer shell has a sliding lock to hold it into place, and unlike cold shrink tubing, slide locks are reusable.   In other words, Slide Locks can be removed and reapplied.  Despite the option of being reusable, Slide Locks are still a great “set it and forget it” option, in the right circumstances. 

In order to truly be watertight, Slide Locks must be made to very specifically match coax connector and cable combinations.  For example, if the cable type going into the slide lock is too small, it may be impossible for the Slide Lock to create a watertight seal over the cable.  For this reason, Slide Locks are only available in 3 sizes, as can be seen in the photos below, (where each Slide Lock is shown both open and closed).

As you might expect, not all coaxial connectors will fit into Slide Locks.  For example, field-terminated connectors, (like JMA connectors), will not fit into Slide Locks, even if they match one of the three types of connectors we make Slide Locks for.  Field terminated connectors are simply too large to fit into a Slide Lock.  Slide Locks are made to fit very specific dimensions and if your connector or cable does not match than it often becomes a better idea to use a different RF weatherproofing option.

Gamma RF Cable Weatherproofing Slide Lock

The last thing to note is that although Slide Locks are reusable, the longer they are left up the less reusable they become.  If you leave a Slide Lock up on a connection for several years, for example, the inner silicone gel will become more like a permanent mold around the connection.

We find that many of our customers who utilize Slide Locks use them as a permanent solution and love having the option to re-access connections easily, or possibly re-use the Slide Lock if circumstances permit it.

RF Weatherproof Boots are incredibly easy to install as they simply slide up and over the connection.  They slide back off of the connection just as easily, making them a great coax connector weatherproofing solution, especially when you are concerned about re-accessibility to the connection.

There are several types of boots on the market and we take pride in having a one-piece boot solution.  Some boots have a two piece, interlocking design but in our testing we have not noticed any noticeable improvements that merit the two piece design.  Our one piece boots are tested to meet IP68 standards, meaning that we place our boots over a coax connector and dunk it into a tank of water over 3 meters deep and for over 30 minutes.  Once removed, we carefully remove the boot and inspect the connection for any signs of water.  There must be no signs of water ingress in order for our boots to meet IP68 standards, which all of our boots do.

Beyond the weatherproofing results however, we take pride in our one piece solution because of the ease of installation. Two-piece boots typically need to be custom cut at the time of installation.  Not only does this result in a much longer installation, but we have heard many stories of dropped parts and bad cuts happening on site.  Our boots avoid these problems entirely.

Weatherproof Boot for SMA Connectors on LMR195 Cables

Like all RF weatherproofing, there are things with the boots you should be aware of.  First, boots must be made to match both your connector and cable.  We offer 12 different types of boots to match different connector and cable combinations, all of which are IP68 rated.

Secondly, for best results boots should be placed on a cable before the cable is terminated, (aka connector is installed on the cable).  We sell cables with our boots already on the cable to help solve this problem.  We also sell the boots on their own for those who are terminating their own cables. RF Weatherproof Boots also have the added benefit of being one of the only types of weatherproofing for coax connectors that has a right-angle option.

Gamma RF Cable Weatherproofing Boot

In some cases it might be possible to put a boot onto a cable that has already been terminated, (connector has already been installed).  However, we cannot guarantee that a boot will be able to be installed in these cases, nor can we guarantee the results of the boot.

Our customers love boots, but typically they order them already on cables or they are going to terminate the cables themselves.  We also offer another type of boot, called the Suppressor Boot, that not only weatherproofs coax connectors, but also reduces RF interference at those connections.  You can learn more about Suppressor Boots here.

Magic Tape is known by many names: self-amalgamating tape, self-fusing tape, cold shrink tape, etc.  Whatever the name may be, the key feature that makes this tape so appealing is that it does not have adhesive.  This is important when it comes to RF weatherproofing in general,  as adhesive tends to melt in the heat and becomes brittle and less effective in the cold.  Long story short, adhesive and outdoor weatherproofing is, more often than not, a bad idea.

This is what makes Magic Tape so appealing, (it’s also why all of Gamma Electronics’ RF Weatherproofing products do not utilize adhesive).  When you stretch Magic Tape and layer it on top of itself the two layers of tape interweave, or “self-amalgamate.”  It creates an incredible bond often described as “self-fusing,” and because it does not require heat or adhesive  it has also earned the nickname of “cold shrink tape.”

You can see Magic Tape in use in the video below.

Magic Tape is a fantastic solution but it should be noted that how successful it is as weatherproofing is highly dependent on the person installing it.  Cold Shrink Tubing, Slide Locks, and RF Weatherproof Boots are all a bit more foolproof when it comes to the installation process.  Magic Tape is easier to install than other solutions, (see Tape & Butyl below), but still requires some know-how.

We largely recommend Magic Tape for odd shaped connections that you might have trouble finding a solution like cold shrink, slide locks, or boots for.  Magic Tape is also great to keep around in case of repairs/maintenance.  You may not always have the exact size cold shrink or slide lock you need, but it’s pretty easy to keep magic tape on hand.

Gamma Electronics Magic Tape stretched out

Tape & Butyl is one of the most commonly used forms of weatherproofing because it is typically the cheapest.  As the saying goes however, you get what you pay for.

Tape & Butyl is in all actuality two types of weatherproofing being used together.  The tape is almost always electrical tape, which is typically applied as the first layer around the connection. After a layer of tape, butyl is applied.  Butyl is a thick, clay-like material that is meant to block any water from working its way into the connection.  The butyl is applied by hand and molded around the connection.  Afterwards, another layer of tape, (or more), is layered around the butyl to hold everything together.

While tape and butyl can work, (in certain conditions), it is very likely that it will need to be replaced within a year.  The reason for this is that the adhesive on the tape tends to break down, leading to the tape unraveling around the butyl.  In addition to the adhesive breakdown, butyl tends to melt and become runny in the heat.  Butyl is well known to melt its way into coaxial connectors, often causing VSWR issues.

Cold is also problematic for butyl, as butyl tends to become brittle and starts to crack in the cold.  These cracks eventually mean you have openings for water to work it’s way into the connection.

Lastly, tape and butyl is a long install process, and a terrible uninstall process.  Oftentimes cables are simply replaced after tape and butyl have been applied to them rather than even trying to cleanly remove the tape and butyl.

Over the years tape and butyl have slowly been seeing less use, but they certainly have not been phased out altogether.  We nearly always recommend avoiding tape and butyl as they have much longer installation times and require far more maintenance than other weatherproofing solutions.

 

Tape & Butyl Weatherproofing Cut Open
Tape in the Wind

Heat shrink tubing, like cold shrink tubing, is a rubber sleeve that can slide up and over a connector and be shrunk down with heat to create a protective layer over a coax connector

Can you use Heat Shrink Tubing for coaxial connectors?  While it is possible, we do not recommend it.  There are a few reasons as to why.

First, to create a watertight seal you would need to use a heat shrink tubing that has adhesive.  As discussed in the above sections, adhesive is not reliable outdoors, specifically when you need your weatherproofing to hold up against both the heat of summer and the cold of winter.

Secondly, most heat shrink tubing is made to work inside machinery like cars, tractors, and aircraft.  That means that the vast majority of heat shrink is not meant to see direct exposure to sunlight or have direct contact with rain and/or snow.  There is heat shrink tubing that is made to be UV resistant, (we offer one), but it is unlikely to create a watertight seal the likes of cold shrink, Slide Locks, Boots, etc..  This returns us back to our first point about heat shrink tubing, which is that it requires adhesive/glue to create a watertight seal: not ideal.

Lastly, as the name suggests, heat shrink tubing requires heat to be installed, and typically very high temperatures at that.  Most heat shrink tubing will only start to shrink around 200° Fahrenheit, (with some tubing requiring much higher temperatures), which means a heat gun or blow torch is needed.  Heat guns and blow torches not only make the installation process more complicated and time consuming, but also more dangerous.

To make a long story short, as much as we love heat shrink tubing, (and we really do), we cannot recommend it as weatherproofing for coaxial connectors.

Conclusion

There are numerous ways to weatherproof a coax connector but ultimately the decision on what to use comes down to your needs.  We often find that customers will purchase different types of weatherproofing that all go on the same tower.  It is truly, highly dependent on your needs.

What is important to consider however, is that choosing the right coax weatherproofing can vastly reduce your maintenance and your installation times.  Choosing the wrong RF weatherproofing in the beginning will almost always come back to haunt you in the end.

Try 3 for $25

We’ve made it easy for you to try something new with your coax weatherproofing.  Try 3 of our coax weatherproofing products for only $25, including shipping.

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