Runcible Blog

automotive bandaid

I was thinking about how durable my auto body repairs will be, and I don't think they will last very long. First of all, Bondo isn't really considered a permanent fix (I think) even if it is professionally done, which it hasn't. My decision to use aluminum flashing as patches rather than the recommended sheet metal could prove to be the weak link in the repair. For one thing, aluminum bends more easily, and if it bends enough (or even if it just flexes back and forth a lot over a period of time), the Bondo supporting the whole structure is liable to crack and fall off. And if that doesn't do the trick, there could be some trouble in the summer as the aluminum embedded inside Bondo starts to expand. "Steel's thermal expansion is 1/4th that of aluminum's. When using a hybrid steel and aluminum design concept, the difference in expansion rates may cause premature failure of joints and fasteners. " And "Aluminum's galvanic potential is high, while steel's is low. On an auto body, when aluminum and steel are in direct contact, accelerated corrosion is evident. " That conjecture could be a worst case scenario though. The Bondo is really thick -- I slathered it on pretty liberally. I don't know how much vibration the wheel wells and quarter panels receive, but the thermal expansion issue might crop up. Basically, I have no idea what will happen, but if my Bondo car crumbles, I'll get another can of that wonderful substance... After I primed and painted one side I realized that I got the wrong shade of gray spray paint. It seemed close enough at the time, but I guess it looks different when you put it on the car. Now the repairs scream "Look at me! I'm a poorly-done repair! Check out the masking tape marks and the paint splatter on the bumper! Rock on!" (At least that's what it screams when the paint and Bondo fumes grab ahold of me...) To cap everything off, I might add a design or write my name on the hood. Now that's classy.