Best Waterproof Cable Glands for Solar and Rooftop Electronics

Cutting holes in a vehicle's roof, wall, or floor will make anyone cringe. Every new entry point made for solar, internet, or rooftop electronics cables is also a new potential vulnerability. The last thing you want to hear when falling asleep is the sound of water dripping through the roof of your beloved 2-year-old Sprinter van. 

As a problem-solving business, we love to find solutions to obstacles that businesses and end users face when designing electrical systems. As we all know, the devil is in the details… Often it is the components you don't see that become the problem child.

Unfortunately, the best solution is often not the cheapest option on Google Shopping, but rather the one that has undergone the most rigorous material research and real world testing. Scanstrut, a UK-based company, is on a mission to design and manufacture the world's #1 Waterproof cable seals for solar installations and other roof penetrations on boats, vans, and RVs.

After testing these products ourselves, here are our observations:

Sea-worthy. Road-ready.

The first thing we noticed when handling these cable seals was their solid construction. Each model is made with marine-grade materials and is IP68 certified, providing full protection against water and dust. Similar to Victron Energy, Scanstrut’s products were originally designed for marine environments where standards for durability tend to be much higher in comparison to the RV/Van industries.

Electronics on boats are highly susceptible to damage from water, dirt and general heat/humidity which cause corrosion, expansion, and contraction around penetrations. Mounted solar panels and cables are also under considerable strain from wind and waves.

Consider the amount of stress that cables undergo due to constant wind force when a vehicle is in motion, or even when parked under accumulating ice or snow. Having a cable seal that is not only 100% waterproof but also offers relief from vibrations and wind strain is a big value add.

Scanstrut has a range of different cable seals available, varying in size, shape, and color. For solar panel installation, check out the DS-HD6-BLK double horizontal cable seal. This design is unique as it allows you to install 2 cables - 5mm (0.19”) and 6mm (0.23”) in any combination, making it perfect for routing two solar panel cables externally to internally on the roof of a van. They also offer the same design but in a larger size which allows for 2 cables (6-10mm or 2.61") to be installed through the same seal. Their compact, low-profile footprint allows these cable seals to be installed as close to the panels as possible.

Scanstrut's new Low-profile Vertical and Low Profile Multi Cable Seals maintain all the same great features and functions but with an even cleaner, flush-mount design. 

Secure Cable Management. No Messy Sealant.

Silicone and lap sealant are, in many ways, the duct tape of the camper Van and RV world. Do they work? Sure. How long do they last? Hard to say.

Some may argue that no one will ever see their rooftop, so why spend money making it look nice? That's fair. RVs parked on the street or in a barn have few rooftop admirers. An urban van owner with their baby parked on the driveway may have stronger feelings about how clean or messy their installation looks. Scanstrut cable seals provide a 100% watertight seal - without sealant.

We love the clean design of these cable seals, how they transition into the roof, and how their physical profile keeps water moving - not pooling. If you've been in the recreational vehicle business for a while, you've seen how uneven surfaces created by gobbed-on sealant are prone to mold build-up around the seal.

If it's important to have easy access to each roof penetration, Scanstrut’s cable seals have a lot going for them. Say you want to add more solar panels to your roof or rewire your existing panel for higher voltage. Or maybe you want to run a second cable for a rooftop lighting system? Long-term, having easy access to each roof penetration without scraping it up and having to remove silicone sealant is a big deal.

The DS-MULTI-P-BLK Multi Cable Seal is the most versatile cable seal made by Scanstrut. It comes with an un-drilled bung (or stopper), which allows you to drill custom holes to match your exact cable requirement and to route multiple cables up to 15mm (0.59in) through the same seal. The max you would probably want to route is 3 or 4 depending on the cable size, but its adaptive design makes it attractive for use in a long list of installation scenarios.

The new DS-H-MULTI-BLK Horizontal Multi Cable Seal can, likewise, be used to route multiple cables up to 15mm (0.59in). 

Designed with OEMs and Solar Installers in Mind

Whether you're building 5, 10, or 50 custom vans in a month, each step of a design-build process needs to be efficient, and it needs to be done right the first time. Craftsmanship is in the details, and less messing around during installation means less time and money wasted. Scanstut has made it easy to route cables efficiently and securely so that you can focus on more critical tasks.

How does Scanstut streamline the installation process?

• They're designed for quick and easy assembly without fancy tools or complicated procedures.
• They come ready to be adapted to a variety of cable and connector sizes. The DS-H10-BLK single horizontal entry cable seal, for example, can accommodate cables between 6-10mm (0.24" -0.39").
• Both pre-drilled split and blank bungs are included in most models, so you can drill the cable size you need. Captive nuts help you from dropping and losing them during installation.
• Scanstrut's vertical cable seals, like the DS30-P-BLK, come with a split grommet option meaning you don't have to cut off cable connectors before installation.
  
• All Scanstrut cable seals come with a 2-year warranty. If you have an issue, we'll work with you to process that warranty request and get a replacement seal coming your way.
  
• We also appreciate having the choice to ship glitzy retail or OEM packaging to minimize waste.

If you're a custom van builder or installer, interior water damage to electrical systems or custom finishes is not something we want to worry about - ever. Using good quality penetration seals not only raises your game as a builder but will also save you time and money in the short and long term.

Curious Minds Would Like to Know . . . .

What's the most foolproof way to drill a blank bung?

There are a few tips to remember to get accurate and neat results. One is freezing the blank seal in a freezer before drilling. This may seem unusual, but it can significantly affect the outcome. Freezing the blank seal will make it much easier to drill a neat hole.

For best results, try drilling a hole approximately 1-2mm larger than the diameter of the cable you will be using. This will help ensure a good fit around the cable and make running the cable through the hole easier.

It's worth noting that when you drill into a frozen blank seal, the hole will appear much larger than you anticipated. However, once the seal defrosts, you will find it is a good tight fit and provides a secure, strain-resistant seal.

What keeps water from dripping down the wires through holes I drill in the bungs?

If you drill holes that are no more than 1-2mm larger than the wires you will pass through, once you put it in, the rubber bung essentially closes around the wires and creates a secure, waterproof seal. The cable seal cover, which is installed last, further compresses the rubber and strengthens the seal.

Each Scanstrut cable seal comes with an individual installation guide which you can review from each product page under the ‘Downloads’ dropdown. Broadly speaking, here are a few installation tips that apply to all Scanstut cable seals:

1. Choose the right size: Scanstrut cable seals come in different sizes to accommodate a range of cable diameters. Cable size ranges are marked on each product page. Pre-drilled and blank bungs are also included in all cable seal models so that you can drill holes for your exact cable size. Vertical cable seals come with split bungs in addition to drilled and undrilled bungs. 
2. Prepare the hole: Before installing the cable seal, you must prepare the hole where the cable will pass through. Make sure that it's clean from any debris that might prevent a tight seal. Cut-out and tape-down templates are included with some models (DS-HD10-BLK and DS-HD6-BLK), which is quite helpful when planning out roof penetrations and avoiding rookie mistakes.
3. Apply sealant: This is entirely optional, but some do it for added peace of mind. Applying a thin layer of sealant to the cable seal and the holes will help create a watertight seal around the cable. Don't glob it on, as the seal must make good contact with the van's roof or the enclosure.
4. Insert the cable: insert the cable through the bung before pushing it into the seal, this will prevent you having to force your cables through and potentially bending them.
5. Celebrate: Pour some champagne on that seal to make sure it is watertight. You've just installed the best water ingress-protected cable seal on the market. 

Scanstut cable seals are ideal for anyone looking for a simple, effective, and reliable solution for sealing cables and wires. Whether you're in telecommunications, traffic management, or any other field that deserves a marine-grade cable pass-through, these seals are ready to work.

Have a question about your application? Send us a message, and we'll help you choose the right seal. If you're a builder, installer, or retail business, ask us about receiving wholesale pricing on Scanstrut cable seals and other high-performance products in our online store.

If you're curious about Scanstrut's wide range of waterproof wireless chargers and USBs learn more here.