On Sat, 31 Mar 2018 08:17:44 +0700, John B.
wrote:

On Fri, 30 Mar 2018 19:27:18 -0400, Ed Huntress
wrote:

On Fri, 30 Mar 2018 18:13:45 -0500, Martin Eastburn
wrote:

Use that new glue - called TIG or something like that :-)
Martin

Right, but even oil from your hands can embrittle a titanium weld. To
get a strong join, the provess is very exacting.

But it isn't rocket science. We welded titanium in the Air Force, in
fact I was certified to weld it as of about 1971. Chemically clean,
don't contaminate the welding area, weld in an inert atmosphere.

Yup.


For certification we welded in a Plexiglas box with attached gloves,
purged before welding, but a mate who worked at the depot said that
they welded it without using an inert box by using a heavier then
normal gas flow and back purging as well. They were welding heating
and pressurization ducts for the C-something and apparently there was
considerable welding to be done.

You've just described "exacting." g

Purged Plexiglass boxes with attached gloves; heavy argon flow;
back-purging...

Jeez, John, do you weld steel trailers that way, too?

What you're describing is exactly what I was talking about.


As an aside, when certificating any color change at all after welding
was reason for disqualification :-)

It's tricky. The trickiness of making strong welds in titanium is the
reason the Soviets made the MIG-25 Foxbat out of stainless steel.

--
Ed Huntress