In article JoeGwinn-79C5EE.21542814052005
@comcast.dca.giganews.com, says...
In article ,
Ned Simmons wrote:

In article JoeGwinn-C1340A.12261514052005
@comcast.dca.giganews.com, says...
In article .com,
" wrote:

[snip]

I would think that soft soldering would work perfectly, and is easily a
factor of ten stronger than any epoxy or loctite compound, so a soldered
connection will last forever in such service.

A factor of 2 would be closer.

Solder metal is far stronger than epoxy or loctite, especially
silver-bearing solder. Even crappy metal is ~20,000 psi, versus ~2,000
psi for plastics.

20 ksi in shear is about right for softer grades of
aluminum. 5-10 ksi shear strength is more typical than 2
ksi for engineering plastics.

Solder does creep, but so do plastics, although epoxy
isn't bad. Solder, being soft, is less brittle.

The really strong epoxies, such as those used for repair of aluminium
airplanes, needs lots of process and care, and high-temperature cure,
and are not all that easily available. Even so, the metal is stronger.


I suspect the reason that
Loctite didn't work was that there was no clearance between
the parts. Solder's not going to work any better under
those circumstances.

This is a good point. Both require a few thousandths of an inch of
clearance to work well, although solder bridges gaps better.

But anyway, soft solder ought to work well.


As I said, soft solder is only about twice as strong in
shear as the most common Loctite retaining compounds. About
8000 psi for 63/37 in a proper joint...
http://www.matweb.com/search/SpecificMaterial.asp?
bassnum=MLSS63

And around 4000 psi for Loctite 680...
http://www.matweb.com/search/SpecificMaterial.asp?
bassnum=PLOCT127

Either one, if properly applied, should be more that strong
enough.

Ned Simmons