If you’re adding a camper to your truck — whether it’s a GFC, Super Pacific, Tune Outdoor M1, or Alu-Cab — sealing your truck bed from dust and water is absolutely essential. For campers mounted on the bed rails, this step can mean the difference between a clean, dry camper and a constant battle with leaks and dirt.
Slide-in campers usually come factory-sealed, but for bed-rail-mounted models, the sealing work is up to you. Here’s our step-by-step process that we use in the shop to protect truck beds before any camper install.
Step 1: Remove the Plastic Bed Caps and Seal the Top
Start by pulling off the plastic bed caps to expose the holes along the bed rails. These are major entry points for dust and water.
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Lay Aluminum Foil Tape over all holes on top of the bed sides, applying one or two layers for durability.
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Use Sikaflex 221 Sealant to seal around each clip location before reinstalling the caps. This ensures a tight barrier underneath the camper’s bulb seal.
Step 2: Seal the Bed Rails and Bolt Holes
If your truck has factory bed rails, remove them and run a bead of Sikaflex around each bolt hole. This is similar to sealing a roof rack, ensuring water can’t seep in.
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Use The Rated Caulk Gun for precise application and a clean finish.
Step 3: Address Large Holes and Corners
Some trucks have large openings or corner gaps that need heavier sealing materials:
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Waterproof & Airtight Sealant Tape – Best for larger holes inside the bed.
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Butyle Sealing Tape – Perfect for stubborn, irregular surfaces.
Seal corners, tie-down mounts, and missing rail caps before applying Sikaflex for extra protection.
Step 4: Install a Tailgate Seal
The tailgate is the most common dust entry point. Even with the bed sealed, dust can sneak in through this gap.
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Install the Tailgate Seal for 2007–2025 Toyota Tundra to add a bulb seal along the edges and bottom.
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Pair it with a bed rug for added dust and water resistance.
Step 5: Perform the Light Test
After sealing, climb inside your bed or camper at night and have someone shine a bright light from outside. Anywhere you see light needs more sealant or tape until it’s fully blocked.
Why This Step is Crucial
Sealing your truck bed before installing a camper:
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Keeps your gear clean and dry
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Prevents rust and water damage
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Eliminates dust buildup inside your camper
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Saves you from removing the camper later to fix leaks
Get the Products We Use:
With the right prep work and materials, you can stop dust and water from ever becoming a problem in your camper build. It’s a few hours of work now for years of clean, dry adventures ahead.