[TheForge] a blacksmithing question and a ceramic/pottery question

[Bruce Freeman]

Terry,

Hello, yourself.  Good to see you back on-line.

I still don't have a very clear idea what this part looks like.  From
the function and complexity, however, I'd be inclined to wing it with
available plumbing connections or something of the sort.

For example, thinking of it as a reducing union, and assuming you can
get to it adequately, why not just adapt an available reducing union
to the purpose?

Alternatively, if access is limited, why not "cast" something in place
-- at low temperature, like a plastic or fiber-reinforced plastic.

What I'm driving at is NOT to try to reproduce the part, just the
function.  Does that make any sense?  Have you posted a  photo yet?

On Thu, Jan 5, 2012 at 1:49 PM, terry l. ridder <terrylr at blauedonau.com> wrote:
<snip>
>
> the part is from the instrumentation panel for a large marine aux
> diesel, which is older than me. as to what the part total functions
> are is not clear.
>
> given the color of the part, we initially thought it was either copper,
> brass or bronze alloy. the part is too light to be a copper, brass or
> bronze alloy. using an optical microscope, an examination of the break
> area leads me to believe that the part is a Beryllium alloy.
>
> why use a Beryllium alloy to make the part to being with?
>
> the instrument panel is subjected to vibration from many different
> sources.
>
> five thermocouple leads join together to form a bundle of shielded
> wires. the broken part connects a nylon lined brass conduit to a larger
> nylon lined brass conduit. so most basically, the broken part acts as a
> reducing coupling. but it also cushions the thermocouple wires from
> abrasion. my gut feeling is that the part is providing additional
> shielding for some reason. was this over engineered in the original
> design phase?
>
> there is no good way to describe the part in ascii art.
> the part has absolutely no draft nor are there any seam lines on the
> part. just looking at the part externally it looks like a hexagon rod.
> it is not till you look internally do you find the complicated nature of
> the part. internally, the part is divided into basically tubes which
> have nylon inserts in them. thermocouple wires are routed through each
> tube. for such a small part it appears to have an important function.
>
> the part fractured just before the internal threads on the larger end.
>
> there is no documentation on the instrumentation panel, parts diagrams,
> parts lists. the thermocouples are all part of the mechanical relay
> control system for the aux diesel. tracing out the relay logic and
> control signals these 5 thermocouples shutdown or prevent the diesel
> from starting if there are any out-of-range temperatures.
>
> if the part cannot be replaced or repaired, we would have to find a new
> control system for the aux diesel. that would require replacing the
> mechanical relay control system. this would require kilobucks.
>
> without the part in place the aux diesel is not reliable. it just
> shutdowns on spurious thermocouple readings.
>
-- 
Bruce
NJ