As I travel around the country giving seminars and training classes , I often get asked if I have a favorite repair technique. The first thing that comes to mind is “Bondo”. Yes, the same Bondo body filler that mechanics use to repair dents on wrecked cars. Here’s my favorite story: A man approached me with a problem on his bay window. The window sill had a rotted area about 18 inches long and it also went slightly under the sash. He had gotten estimates to replace his bay window unit for about $2000.00. That included removing the old bay window, supplying and installing the new one and painting it. He asked me if I had any ideas to avoid this costly repair and I told him that I could repair his window for about $10.00 if he would paint the window himself. He was amazed and immediately asked me to proceed. Here’s how I did it:

I went to a place that sold auto parts and supplies and bought a quart of “Bondo” body filler for just under $10. Then I took a screwdriver and dugout all the rotted wood in the area of the window sill. I allowed it to dry (I sped up the process with a blow dryer) and then mixed the Bondo and hardner as per its label directions. Then I scooped the bondo mixture up and put it in a one-gallon ziplock baggy. After squeezing the bondo into the corner of the baggy, I cut the corner of the baggy and used it like a cake decorator would. I slightly overfilled the cavity created from scraping out the rotted wood and then took a paint stir stick (free from anywhere that sells paint) and used it to push the Bondo into all areas needed. After about 10 minutes, the Bondo dried to solid form. Then I used a palm sander with 200 grit sandpaper to sand the widow sill smooth. We took a piece of the window sill that we scraped out that had paint on it to the paint store and had the color computer matched. The man bought a quart of the matched paint and painted the window and it looked as good as new, saving him literally almost $2000.00

Here are a few more things that you can do with Bondo:

    • Fill in holes and cracks in plaster walls with Bondo. It’s permanent and drywall mud sometimes falls out of plaster wall repairs when disturbed or bumped.
    • Make repairs in handrails, floorboards, steps, seats and seat backs on decks with Bondo. Then just sand smooth and paint.
    • For holes in hollow core doors, just fill the hole with tin foil for a backing, spread Bondo generously over the hole and let it dry. Then sand it and paint the door for a permanent fix.
  • Bondo can also fill cracks in concrete as long as the concrete surface is to be painted afterwards. The color won’t match the concrete, therefore you need to paint it. I will sometimes add sand (regular white play sand) to the paint to match the texture of some surfaces.