You’re getting ready to fish wire through a wall, have just cut open the hole to place your mud ring, and are suddenly met with the dreaded fiberglass insulation. It’s fluffy, it’s pink, and it’s everywhere.
You already put a large hole in your wall, so there’s no turning back. How are you going to fish a wire through this thick padding?
Before you start removing the insulation by the handful, try our tips and trick below to fish a wire through an insulation wall.
What are the different ways you can fish wire through an insulated wall?
What tools will you need?
Keep reading to find out!
1. Feed the Wire Along the Corner of the Wall
Depending on the insulation, you may be able to feed the wire along the corner of the wall cavity. This may not be possible if you find that the insulation is very dense and stiff. However, this is a great and easy option if the insulation is sparingly packed and fluffy.
You will need a standard bull-nose (or loop) tip fiberglass rod. If you don’t have a bull-nose tip, see the KOOTANS 11 ft Fiberglass Wire Running Kit , which includes all the wire fishing essentials.
When drilling the entry and exit holes, position them near the corners of the wall and line them up as best as possible. This will make weaving the wire through much easier.
Attach the wire to the bull-nose tip and position it against the corner of the wall cavity. Try to get it as flush to the corner as possible before feeding it down the wall.
Steadily, but firmly, push the wire down the wall. Retrieve it from the exit hole and you’re good to go!
If you’re new to the world of wire fishing, watch the video to learn about the different fishing rods and their functions.
2. Use a Magnetic Fishing Bit
Using a magnetic fishing bit, or drop magnet, is one of the easiest ways to fish a wire through insulation. This method involves pulling the magnetic tipped wire out of the exit hole by guiding it with a strong magnet rolled against the wall.
Attach your cable to the end of the drop magnet and drill your entry and exit holes. Note that the drop magnet is larger than the end of your average fishing rod, so you’ll need to drill a wider entry hole.
Once both holes are drilled, you can feed in your drop magnet. You may need to remove some insulation at the entry point so the drop magnet has space to enter the wall cavity.
Once the drop magnet is inserted, use the provided magnet to feed it through the wall. You may have to use short, repetitive stroking motions to move it through the insulation.
You should be able to feel the drop magnet stick to the wall and latch onto the handheld magnet. Don’t worry if you don’t feel it instantly. Slowly move your magnet around the wall until you feel the fishing bit’s magnetic pull.
Once you feel the drop magnet near the exit hole, reach in, pull it out, and you’re all set!
There are several magnetic wire fishing sets on the market, but it’s important to choose your magnet carefully. The magnet drill bit and roller need to be very strong, or you risk losing the drop magnet amid the insulation in your wall.
Check out Magnepull XP1000-LC for a professional magnetic wire fishing system on Amazon.
Watch Lawrence Systems’ informative YouTube video below demonstrating how to fish wire through insulation using a magnetic fishing bit.
3. Use a Magnetic Ball-Chain
Similar to the magnetic fishing tip, a magnetic ball-chain also uses a magnetic pull to fish a wire through an insulated wall. This is a limp chain made of magnetic balls which are small enough to weave through insulation. It is used with a long, bendable, magnetic retriever.
Screw the magnetic ball-chain to the end of a standard wire fishing rod. You can use more ball-chain if needed.
Place the chain into the entry point and try to feed as much of it as you can into the wall, removing minimal insulation if necessary. Bend the magnetic retriever into an L-shape and insert it into the exit point. Try to stick as much of the magnetic retriever into the wall as possible.
Move the retriever around inside the wall until you feel the ball-chain attach to it. Now you can slowly pull the ball-chain out of the exit point. Be gentle when doing this to avoid detaching the ball-chain from the receiver.
Retrieve the chain from the exit hole and fish the rest of your wire through the wall.
If you’re in the market for a magnetic ball-chain, check out the Jonard Tools MRS-24 MagneTriever™ .
Watch the video below demonstrating how to use a magnetic ball-chain:
4. Use a Flex Fishing Drill Bit
Using a flex fishing drill bit is a great alternative to fishing a magnet through the wall, but it doesn’t come without its risks.
This solution is a small corkscrew-shaped bit attached to your fishing wire. The wire is attached to a drill, triggering the bit to spin and cut through all in its path.
While this solution will work for getting through insulation and fire stops, you need to exercise extreme caution. You don’t want to lose control of the fishing wire or point it in the wrong direction and have it come through the drywall.
You must wear safety glasses to prevent any drywall or insulation from going into your eyes. It’s also essential to wear leather work gloves as the friction from the spinning wire will heat up and burn your hands.
Although effective, this should only be used as a last resort.
Make sure to cut out a large enough hole to feed your drill bit into and allow you enough space to angle it in the right direction.
Place the flex fishing drill bit into the cavity and angle it downward so it’s not pointing towards the wall. Turn on your drill and guide it down the wall. Once it’s at the same level as the exit hole, turn off the drill.
Do not attempt to immediately grab the wire with your bare hands as the drill bit may be hot.
Once the bit is cooled or you’re wearing work gloves, reach in, grab the wire, and pull it out!
If you’re interested in using a flex fishing drill bit but don’t know where to find one, see the Eagle Tool Flex Shank Installer Drill Bit .
This method may sound simple, but it takes some practice.
Margaret Raunch – Just Needs Paint on YouTube has a great video demonstrating the dos and don’ts of using a flex fishing drill bit. Watch the video below!
Yesenia Achlim is a technical copywriter and editor with a focus on AV equipment. She aims to break down complicated topics and make technology accessible, no matter your technical expertise. When she’s not teaching you how to replace a projector lamp, you can find her reading and baking.