Sealing the School Bus Windows

Sealing school bus windows is an extremely important step.

If you skip this, you are setting yourself up for leaks that can ruin your in-wall insulation, subfloor, wall paneling, and whatever you in front of those bus windows.  And once you build up, you can’t go back.  So it’s worth three days of work to completely remove and re-seal those windows.

Required Tools & Materials:
  • Drill or impact driver
  • Utility knife with a brand new razor (needs to be super sharp)
  • Painter’s Tool (no joke, you will use this for EVERYTHING in your bus conversion process!)
  • Paintable Silicone (buy it in bulk, you’ll use this over and over again in your conversion and buying bulk will save you big time)
  • Mineral spirits
  • 3-in-1 caulking tool from Home Depot
  • Rags that can get gross and nasty

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Step 1 – Remove the Window
  1. Use the utility knife to cut a line through the current caulking or butyl tape
  2. Use the drill or impact driver to remove the U-shaped brackets helping hold the window in place
  3. Start rocking and pushing, hitting with her palm here and there, to wedge the window free.  It can help to open the window so you have the middle bar of the window to hold on to.
Step 2 – Clean the Opening and Window
  1. Go to town with the painter’s tool to completely remove the old caulking from the open frame.  Don’t worry about pulling up old paint, the aim here is to completely get rid of that old caulking and get a clean and smooth surface.
  2. Use mineral spirits to clean up any remaining spots, so that the surface is clean and free of any more dust/caulking/grease.
  3. Use the painter’s tool and mineral spirits to completely clean the window itself.  And take this as an opportunity to get those panes squeaky clean!
Step 3 – Re-Seal the Window
  1. Put the window back into place and secure the U-shaped brackets
  2. Apply the caulking along every single seam and use the caulking tool to smooth over and create a solid seal
    • Note:  We used 100% silicone, which has created an AMAZING seal (we have had zero window leaks), but it came at a price.  Now the inside edges (and everywhere a little silicone smudged around) is unpaintable.  We don’t like this, so we wish we had used paintable silicone.  It’s not 100% silicone; they have to include additives (probably acrylic) to make it paintable, but the silicone percentage is high enough we feel it would have created just as good of a seal.

WORD TO THE WISE:  Did you know that NOTHING sticks to 100% silicone except silicone itself??  This means no paint, no stickers, no nothing will EVER stick to something you’ve painted or sealed with 100% silicone.  We know some folks who painted their whole bus with Henry’s (100% silicone) without realizing it meant they could never paint another color over that.  Bummer.  So now you know!

Next, removing the ceiling panels and old ceiling insulation!