How to Make Magnetic Window Shades for RVs, Camper Vans, and Motorhomes

Magnet spacing

One near each corner, then every 4 to 6 in on fabric

Hold to aim for

7 to 10× the shade's weight, 10× on thin steel

Aluminum frames

Not magnetic: add steel discs or magnets

Heat rating

176 °F (80 °C) for the magnets in this guide

Magnetic shades go up in seconds, sit flat without suction cups or screws, and come down just as fast when you drive. The same method makes magnetic blackout curtains for sleeping in, insulated RV window covers for cold nights and reflective van window insulation for summer heat.

Choose a Shade Construction

All four block light when the edges are sealed. What differs is how warm they keep you, how they store, and how thick the edge is where the magnets go.

Reflectix-Style Foil and Bubble

Reflective bubble insulation, best known by the Reflectix brand, is a bubble core between two foil faces. The maker lists its standard double bubble roll at 5/16 in thick and about 0.87 oz per square foot, rated from -60 to 180 °F. Cut it with scissors or a utility knife and edge it with foil tape or a fabric binding so it doesn’t tear. Facing the foil toward the glass reflects summer sun before it heats the cabin. Bare foil is very visible from outside, so many van owners cover the window side with black fabric, which hides the shade but absorbs more heat.

Fabric Blackout

One or two layers of blackout fabric toward the window, often with a decorative face fabric on the room side. It’s the lightest build and the easiest to sew, and it packs small, but it adds little insulation. Sew the magnets into the hem.

Quilted Thermal

An outer fabric, an insulating middle layer (polyester batting, an insulated reflective lining or a sheet of foil bubble insulation) and a lining, quilted so the layers can’t shift. It’s the warmest option for cold nights. Its edge is thick, so flatten it with a binding and keep the batting out of the hem, or the magnets sit too far from the frame.

Rigid Inserts

Foam board, foil-faced foam or corrugated plastic cut to fit the window recess or to cover the frame. A rigid panel holds its shape and seals well with fewer magnets, because it doesn’t sag between them: the corners and the middle of each long side on a small panel, or one every 8 to 12 in on a large one. It stores flat rather than rolled. Use adhesive magnets on the panel’s face.

Magnet Attachment Options

Sewing a Pocket for a Disc or Block Magnet

PVC sewing magnets come in a handful of sizes. Sewing your own pocket around an ordinary disc or block magnet opens up the rest of our catalog: thin discs that keep a hem flat, long blocks that fit a narrow binding, and thicker, stronger magnets for heavy covers, placed exactly where the shade needs them. A bare magnet also has no plastic sheath between it and the frame, so more of its pull reaches the steel. Through the same fabric, a 5/8 × 1/8 Inch Disc in a pocket carries about twice the shade weight of a 1/2 Inch Sewing Magnet (see Check the Weight).

1. Size the pocket. Make it the magnet’s width plus its thickness plus about 1/8 in, each way. A 5/8 × 1/8 Inch Disc needs a 7/8 in square pocket, and a 1 × 3/8 × 1/16 Inch Block needs about 1 3/16 × 9/16 in. A snug pocket keeps the magnet on its mark and stops it from flipping over.
2. Put thin fabric on the window side. The layer between the magnet and the frame is the gap, so use a thin, tightly woven fabric there and keep batting out of the pocket.
3. Sew the pockets before the magnets go in. Stitch the hem or binding, then stitch across it to divide it into pockets at your magnet spacing, leaving each one open at one end. Keep magnets away from the sewing machine: they jump to its steel parts, and a needle that strikes a magnet breaks and can chip it.
4. Mark and insert. Mark the face that should point at the window, then slide each magnet in with that face toward the window side.
5. Close each pocket by hand, or leave it removable. Hand-stitch the opening shut, or leave a 1/2 in overlapping flap so you can take the magnets out to wash the shade or move up a size.

Which Magnets to Buy

Magnets for the Shade

Magnets for Sewn Pockets

Any disc or block magnet works in a pocket. These flat sizes sit well in a hem, and their listings are rated 176 °F (80 °C):

Shapes, Grades and Coatings

• Shape: discs are the easiest to sew in and space evenly. For a narrow binding, thin rectangular 1 × 1/4 × 1/16 Inch PVC Covered Sewing Magnets (3.3 lb listed) lie flat along the edge, or sew pockets for bare blocks.
• Grade: N52 gets the most hold from a small, thin magnet; see N42 vs N52 below.
• Coating: our sewing magnets are plated and then sealed in a waterproof plastic sheath. Adhesive discs and most bare discs and blocks are nickel plated (Ni-Cu-Ni), which is fine indoors as long as they don’t stay wet. Use plastic- or epoxy-coated magnets where condensation collects.

Steel Discs for Nonmagnetic Frames

Our adhesive steel discs are 1 mm (0.04 in) thick, nickel-plated steel with 3M adhesive. Pick one a size wider than the magnet that lands on it: a disc that ends right at the magnet’s edge holds far less. A 1 mm disc also limits magnets about 1 in across and larger, so with 1 Inch Sewing Magnets use the 10× end of the sizing rule or a magnet pair (see steel thickness and strike plates).

Buying Advice

• Count before you buy. Use the spacing table below for each window, add them up and order a few spares.
• Poles don’t matter on steel frames. For pairs, you set each magnet’s pole as you sew it or slide it into its pocket.
• One adhesive pack covers both sides of a pair. Most of our adhesive packs come half with adhesive on the north face and half on the south, so one half goes on the frame and the other on the shade.
• Check the temperature rating. All the magnets in the tables above are listed at 176 °F (80 °C). Some of our other listings are rated 149 °F (65 °C), so check before you use a different magnet on a sun-facing window.
• Build one shade first. Live with it through a drive and a hot afternoon before you buy for every window.

How Many Magnets, and How Far Apart?

Two things set the count: spacing, which keeps the edge tight and light-proof, and weight, which the magnets must carry without sliding. For most shades spacing needs more magnets than weight does, but check both.

Spacing

• Fabric and quilted shades: 4 to 6 in. Fabric sags and lets light in between magnets.
• Reflectix: 6 to 8 in. It’s stiffer than fabric.
• Rigid inserts: each corner, then every 8 to 12 in. On a small panel, the corners and the middle of each long side are often enough.
• Everywhere: a magnet near every corner, centered in the overlap, and closer spacing along the top edge, where a shade starts to sag or peel away.

Magnets centered about 1 in outside the opening, with one at every corner, at 6 in and 4 in spacing, and roughly what a bare Reflectix shade with 1 1/2 in of overlap weighs:

Check the Weight

A shade hangs on a vertical surface, so its weight pulls along the frame. Only friction stops it from sliding, and that friction is about 15 to 25% of the magnets’ pull (see shear force). So aim for a combined hold of 7 to 10 times the shade’s weight, and use 10 times on van bodies and steel discs, which are thin steel, and for shades that stay up while you drive.

Weigh the finished shade, magnets and all, on a kitchen scale. Fabric covers, binding and batting can weigh several times as much as the Reflectix alone. Then:

Magnets needed for the weight = shade weight ÷ ounces each magnet carries (from the table below)

Fabric between the magnet and the steel is an air gap, so each magnet carries less through a thick hem. Ounces of shade each magnet carries through thin fabric (0.5 mm), medium fabric (1 mm) and a quilted edge (2 mm):

These are our estimates of the shade weight each magnet carries on steel at the 10× level, from the listed pull force and our magnetic model. A sewing magnet’s plastic sheath adds a little gap of its own (a bare magnet in a pocket doesn’t), and large magnets lose some hold on thin body steel, so treat them as starting points and test. With a magnet pair on the frame instead of steel, each magnet carries about 1.2 to 2 times as much, more through thicker fabric, because a pair holds better through a gap. That assumes a frame magnet at least as large as the shade magnet, since a pair is limited by its smaller magnet; see magnet-to-magnet vs. magnet-to-steel.

Worked Examples

The same check works for a windshield cover: a 3 lb (48 oz) quilted cover with 1 Inch Sewing Magnets at 4.6 oz each needs at least 11 for the weight, and spacing usually calls for three to five times that.

N42 vs N52 for Window Shades

N52 pulls about 25% harder than N42 at the same size (see N42 vs N52). That matters on a shade when:

• The magnet has to be thin, to fit a narrow binding or keep the edge flat.
• The fabric is thick, such as a quilted edge, where the gap already costs most of the pull.
• You want fewer magnets on a heavy cover.

For light Reflectix and blackout shades at the spacing above, the magnets already give several times the hold you need, so N42 or a slightly larger magnet works just as well.

Installation Best Practices

Magnet-to-Steel or Magnet-to-Magnet?

Get the Polarity Right

Polarity only matters when magnets meet magnets. Choose one rule and use it on every window: every shade magnet faces the window with its north pole, and every frame magnet faces the room with its south pole.

• Find the poles with a Magnetic Pole Detector (a red light for north, green for south) or a magnet you’ve already marked. See how to identify the poles.
• Mark each magnet with a marker before you sew or stick it.
• Bonus: with every shade magnet facing the same way, a shade can’t go on inside out. It pushes away instead.
• Roll, don’t fold. A shade with matching magnets won’t stay folded on itself, because the same poles meet. Rolled up, each magnet meets the opposite face of the one beneath it.

Choose and Apply the Adhesive

Our adhesive magnets and steel discs come with 3M adhesive, and on most of our adhesive magnets it’s 3M VHB 4920. It sticks well to aluminum, painted metal, glass and rigid plastic (including rigid vinyl), and poorly to fabric, soft rubber gaskets, polyethylene and silicone. Many RV frames are powder coated, which varies, so test one disc first. For a strong bond:

1. Clean the spot with a 70/30 mix of isopropyl alcohol and water and let it dry.
2. Apply when it’s warm, between 70 and 100 °F (21 and 38 °C). Below about 60 °F the adhesive is too firm to bond well, so warm the RV first in winter.
3. Press hard across the whole magnet or disc for several seconds.
4. Wait 24 hours before hanging the shade (about 90% strength) and 72 hours for full strength.

On Reflectix, stick magnets to the foil face, never the cut edge or bubbles, and cover each with a strip of foil tape. Details are in working with self-adhesive magnets.

Keep the Fabric Gap Small

Every millimeter of fabric between the magnet and the steel costs hold (see air gaps). Put each magnet on the window side of its pocket, use thin fabric on that side, keep batting and seam bulk out of the hem, and press the binding flat.

Plan for Vibration and Sliding

Bumps and vibration on the road slowly walk magnets down a vertical frame. If a shade stays up while you drive:

• Size at 10 times the shade’s weight.
• Add magnets along the top edge, where a shade starts to peel away.
• Rest the bottom edge on the frame lip or sill, so the magnets only have to hold the shade flat (see how to stop a magnet from sliding).
• Use magnet pairs, which pull the shade back into line.

Plan for Heat

In an Arizona State University study, cars parked in summer sun in Tempe had cabin air averaging 116 °F after an hour, while their dashboards averaged 157 °F. Surfaces in direct sun get much hotter than the air. A magnet’s limit is its maximum operating temperature, and the sewing and adhesive magnets in this guide are listed at 176 °F (80 °C).

• Below the rating, most of the loss is temporary. A magnet’s field drops about 0.1% per °C as it warms and its pull about twice that, so near 150 °F it holds roughly 10% less, then recovers as it cools.
• Thin magnets are more sensitive. Thin discs like most shade magnets, working across a fabric gap, can lose a little strength for good below their rating, so keep them off sun-baked spots. Above the rating, the permanent loss grows. See how temperature affects magnets.
• The other materials are in the same range: 3M lists VHB 4920 at 200 °F long term, and Reflectix lists its insulation at up to 180 °F.
• On the hottest windows, face the reflective side toward the glass, and check the frame with an infrared thermometer on a sunny afternoon. If it nears 176 °F, look at our High-Temperature Magnets.

Prevent Scratches, Chips and Rust

• Keep bare magnets off paint. Sew magnets inside fabric or use plastic-coated magnets.
• Lift shades off; don’t slide them. Grit trapped under a magnet scratches paint as it slides.
• Don’t let bare magnets snap together. Neodymium is brittle and chips; the plastic sheath on sewing magnets cushions them.
• Watch for condensation. Windows sweat on cold nights. Our sewing magnets are sealed in a waterproof plastic sheath, but nickel-plated magnets can rust if they stay wet; see are neodymium magnets waterproof? Take insulated shades down during the day so the glass and frame can dry.

Step by Step: Make a Magnetic Window Shade

1. Check the frame. Hold a loose magnet against the frame all the way around the window. Where it sticks, you can attach the shade’s magnets directly. Where it doesn’t (aluminum, vinyl, fiberglass or plastic trim), plan on steel discs or frame magnets.
2. Make a template. Tape paper over the window and trace the outer edge of the frame. Mark a line 1 1/2 to 2 in outside the opening (2 in for 1 Inch and larger magnets), but not past the frame’s outer edge, so the magnets land on the frame and clear the glass and the rubber gasket. Copy rounded corners exactly.
3. Cut the shade. Cut Reflectix or foam board on the line with a sharp utility knife. For fabric, add 1/2 in for the hem or binding, cut every layer and quilt or baste them together.
4. Mark the magnet positions. Lay the template on the shade and mark a spot near each corner, centered in the overlap, then fill in each edge at even spacing (4 to 6 in on fabric). Tape the template to the frame and mark the same spots if you’re adding steel discs or magnets there.
5. Attach the shade’s magnets. Sew each sewing magnet into the hem, stitching through the plastic around it, or slide disc or block magnets into pockets you’ve sewn (see sewing a pocket). On Reflectix or foam board, stick adhesive magnets to the window-facing side and tape over them. If you’re using pairs, check that every magnet faces the window with the same pole.
6. Prepare the frame. Clean the marked spots, stick on the steel discs or frame magnets (south facing the room for pairs) and wait 24 hours.
7. Test it. Put the shade up and check that every magnet lands on steel. Tug it gently down and sideways, tap the frame to mimic road vibration, look for light leaks at night, and check it again on a hot afternoon.

Troubleshooting

• Sewing MagnetsWaterproof, Sew-In
• Disc Magnets with 3M AdhesivePeel and Stick
• Steel Discs & Strike PlatesLow-Cost Target for a Magnet
• Magnetic Pole DetectorShows N or S Instantly

Magnetic Window Shade FAQ