On Tue, 17 May 2016 09:02:15 -0700 (PDT), "
wrote:

On Tuesday, May 17, 2016 at 9:37:37 AM UTC-5, dadiOH wrote:
J. Clarke wrote:

And if you look at their bad example of Bondo, it's pretty clear that
it's really a bad example of surface prep.

Absolutely true.

That and the fact that it was used so extensively. Bondo works well for
smallish areas but over large areas it will eventually fail. It fails
because the wood expands and contracts differentially to the Bondo. The
epoxy material material they promote will do the same thing, just slower; it
is slower because epoxy has a stronger bond than does the polyester resin
used in Bondo.

Great post. All true; Bondo has its place, although not literally as a sculpting material as seen in the video. I have seen it used extensively as a filler before painting where it worked well. But like any product, extensive repairs require some familiarity with the product to get maximum performance. The lack of surface prep was really obvious in the video when they peeled back the hunks of Bondo and you could see the rotted wood the covered. You could also see further deferred maintenance on all the surfaces as well. It looked like an abandoned warehouse to me, so no telling when the work was actually done on those windows, or if it was just another idiot's repair.

Robert
Since polyester filler is not waterproof the wood can rot under the
filler as well.