On Mon, 13 Jun 2005 14:53:48 -0700, David Erbas-White
Use something that will melt the plastic. I think lacquer thinner or
plexiglass solvent should do it.
Don't use to much. Soften the surface of both peices and squeeze them
them together until the solvent evaporates. You might need to sand
the inside a little afterwards.
If you want to remove a little material, you could use epoxy with
chopped glass. Use the piston (with wax paper or plastic wrap between
the piston and the tube) to form the inside. Do whatever you can with
the outside and sand when done - repeat until you like how it looks.
Get the QT real rugh before using epoxy. I'd use 60 grip sand paper
or the dremel.
Methylene chloride (which I am pretty sure is what you are referring to as
plexiglass solvent) is excellent for that sort of repair. MEK will work too
but is just a little slower to evaporate.
For gap filling, Devcon Plastic Welder is an excellent choice - it's a two
part methacrylic structural adhesive that cures through a polymerization
reaction much like epoxy, with the exception that it bonds like a maniac to
PVC, ABS, styrene and the like. We use an industrial version for various
bonding chores with dissimilar materials, but you can find this in hardware
store glue departments, and it comes in tubes much like 5 minute epoxy. As
it is a polymerization reaction versus a "drying" solvent evaporation,
shrinkage is next to nothing and thus it is good for gap filling and other
Google "Devcon Plastic Welder" and you'll find info, and a picture of what
you're looking for if you want to give it a try. BTW it doesn't smell very
nice, but neither do burned out motors. If you've ever cut plexiglass the
smell is about the same.
p.s. I do tend to jump in and prattle on about methacrylic adhesives at
every opportunity.. but they are a great choice for certain jobs.
Every hardware store in the US sells PVC glue for water piping. I've
never tried it, but it should work. It's also got some sort of filler to
give it a little body, which will help it fill cracks and means it won't
be running down the tube melting/deforming as it goes.
Mark E. Hamilton
It looks like you've gotten a lot of ideas about what kind of adhesive
to use. Let me suggest that you drill a small hole (say 1/16") at the
end of the crack to stop it from spreading. This is common on aircraft
windshields, plastic wing tips, etc. The crack spreads because the
sharp corner at the end creates a stress concentration. Drilling the
hole eliminates this stress concentration.
David Erbas-White wrote:
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.