DIYbanter - View Single Post - Removing *some of* the paint from a wooden door, smoothing thesurface for new paint

dadiOH[_3_]

wrote:
On Tue, 17 May 2016 10:37:28 -0400, "dadiOH"
wrote:

J. Clarke wrote:

Even though Bondo wood repair did not last long, it did last
longer that what you suggested.

The poster and video people were shills for "Better to use
Abatron."

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

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.

The exception is plywood and it is an exception because ply doesn't
respond to weather/humidity changes as much as solid wood.

Time was that many home built boats, usually trimarans, were built
with plywood which was then covered with layers of fiberglass all of
which were adhered with polyester resin. In fact, I have a pram I
built eleven years ago in that manner; it is still good as gold.
Numerous commercial boats were built in the same manner; the Newport
40 ketch was one.

Other than just replacing the rotted wood in the video, the guy
would have done better by cutting it out to good wood, then building
it up with plywood.

You have to admit though that a boat built that way with epoxy, or
even vinyl-ester? resin stands up better than poyester resin ( Like
the old Uniroyal Vibrin)

Probably so but epoxy wasn't all that common back then.