On Thu, 16 Apr 2020 08:08:09 -0500, amdx wrote:

On many of my plastic repairs, I strengthen them be drilling and
inserting a 0.025" steel rod that I glue in place. Sometimes two, if it
is large enough. Sometimes I temporarily glue it in place to get proper
alignment while drilling. It has saved me a lot of time waiting for
parts. I also have a drill and tap for a 1-72 screw if that is needed.

I do something similar when desperate. Instead of drill and pin, I
use a flexible sewing pin (not a needle) and my soldering iron. I put
some gouges in the surface of the pin, heat the pen head, shove the
pin into the parts that I want to glue, and wait for the plastic to
harden. When done, I cut off the head of the pin with flush cutting
diagonal cutters or a Dremel tool with a cutoff disk. If I need pull
strength, I use a straightened paper clip instead of a pin. The paper
clip metal is softer, so I can use my wire cutters to roughen the
surface of the paper clip. I heat instead of glue to assemble the
parts because the hole is usually in some inaccessible location that
can be reached with a soldering iron, but not a Dremel drill tool.

Another alternative is plastic welding.
https://www.harborfreight.com/plastic-welding-kit-with-air-motor-and-temperature-adjustment-96712.html
https://www.harborfreight.com/plastic-welding-kit-with-adjustable-temperature-96464.html
I modified a spare tip for my SMD hot air desoldering tool by adding a
smaller nozzle suitable for plastic welding. So far, it's worked
nicely for parts about the diameter of a pencil. However, my attempts
at plastic welding small parts usually result in a blob of plastic or
a cloud of plastic smog. The next time I get a laptop in the shop to
fix, with the usual ultra-thin standoffs broken off by the threaded
brass inserts, I'll give plastic welding another try.

As you are aware, it breaks where at the point where it needs the
most reinforcement.

Yep. However, my usual problem is finding the broken off plastic
piece.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558