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

[terry l. ridder]

hello ries;

long time no read.
reply intermixed below.

On Thu, 5 Jan 2012, Ries Niemi wrote:

>
> A whole lot more info would be needed.
>

i totally agree. it is taking time searching old marine repair shops
and talking with the older marine mechanics.

>
> You kinda intimate it might be metal- but what metal is it now, what
> does it do, does it carry any load, what are the hardness, temperature,
> lubrication, and strength requirements?
>

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.


>
> Sometimes you need to have a new part cast. Other times it can be
> machined, forged, or fabricated.
> Depends totally on the part.
> I have replaced older aluminum parts with steel, plastic, stainless,
> or bronze, depending on application.
>
> Some parts just arent worth fixing- I had a pair of gears once that
> were not available as parts- price quoted was $500 each to make new
> ones. In that case, it was worth it, as they were needed on a
> $15,000 machine.  Other times, no.
>
> ries
>
>
> Ries Niemi
> Industrial Artist
> www.riesniemi.com
>
>

-- 
terry l. ridder ><>