[ARC5] Stuck WWII Connectors.

[Brian Clarke]

Hello Dave,

There is no need to go beyond the boiling point (BP) of water. Water has three states - solid, liquid and gas. At any temperature above water's freezing point, water has a positive gas pressure, that is, it will evaporate. At sea level, the BP of water is approximately 212 degrees F, or 100 degrees C. I say 'approximately' because the BP depends on actual atmospheric pressure; water's BP is only 212 degrees F at 29.92" mercury or 15 psi - the BP falls with reducing atmospheric pressure. Incidentally, that's why getting a good cuppa tea at the top of a mountain requires a longer steeping time.

Another problem with setting your oven thermostat at 250 degrees F, is the hysteresis of the thermostat; in home appliances, that hysteresis can easily be plus and minus 20 to 30 degrees; they are not scientific instruments. And thermostats are usually insensitive to atmospheric pressure.

A major problem with heating materials that include condensed water is that when the water turns to gas at BP, that gas escapes very energetically and may damage the Bakelite permanently. While Bakelite can stand 285 degrees F continuously, it starts to degrade beyond 570 degrees F.

So, to avoid destruction as steam escapes and as your thermostat goes to its maximum hysteresis excursion, I would suggest using a thermostat setting around 175 degrees F for a longer time.

73 de Brian, VK2GCE

On Sunday, 15 November 2020 6:17 AM, Dave said:
Most of us have heard this before,
but for those who have not:
I was hunting through WWII Navy
connectors this morning.  All the ones
I picked were stuck fast in their shells.
The Bakelite will absorb moisture over
time, swell and stick in the shells.
One can destroy the connector
attempting to remove the inserts
at this point.

https://photos.app.goo.gl/NDM2e22j3SpQiRQZ9

I preheated my oven to 250 Degs F.
Needs to be higher than boiling water (220 Degs F.)
Left them in the over for 1 hour.
Then pulled them out and let them cool
completely- about another hour.

All but one are now completely loose in
their shells, with the one Army connector
being slightly sticky and needing a bump
to get it out.

https://photos.app.goo.gl/YGJAj57GY527G26N6

In case someone hasn't heard of this.
73 Dave AB5S