I agree. Most devices are expected to be heated briefly to soldering
temperatures, not heat soaked at that.
Temperature in this case is much different than heat. The designers of
the devices must take into account what temperature is require to do the
solder assembly function, and minimize the amount of heat the device is
exposed to.
On wave soldering machines the heat was quite low, and these would have
been assembled then. Even with current radiant oven techniques, the
parts would fall off if there was an extended heat exposure. They do
that often enough now with heating problems with devices, with open
circuit failures happening.
If you're lucky and have a quick fire department response, the setup
time on the equipment is at least 4 or 5 minutes. Unless there's
physical danger and the building involved may have people trapped, they
take time to assess the fire, the propagation and there's more time
before they attack.
I've seen a couple of events and a couple of full exercises, it doesn't
happen quickly. Fire departments are sadly known for letting buildings
burn into the basement if it saves life or property of other nearby
structures. You'd be lucky to get this out of a burned out building in
most cases. Once the fire is knocked down the heat will be present for
quite some time afterwards, as they let it cool and clear flash fires,
and take care of nearby property.
thanks
jim
On 10/11/2020 7:21 PM, William Donzelli via cctalk wrote:
How long do you think those poor machines cooked? I bet far, far
longer than the soldering temperature spec. likes.
--
Will
On Sun, Oct 11, 2020 at 10:06 PM dwight via cctalk
<[email protected]> wrote:
Most components can stand soldering temperatures. It is clear that it was only
hot enough to melt plastics. That isn't even hot enough to damage boards. It is
wasn't powered at the same time, it is unlikely to have been harmed. I've seen
cases where there were flames in the board area and parts were not damaged.
These were mostly wrapped in their cases. Melted plastics most likely protected
the boards from dangerous temperatures.
Dwight
________________________________
From: cctalk <[email protected]> on behalf of jim stephens via cctalk
<[email protected]>
Sent: Sunday, October 11, 2020 6:49 PM
To: William Donzelli via cctalk <[email protected]>
Subject: Re: FIRE SALE!
On 10/11/2020 6:34 PM, William Donzelli via cctalk wrote:
I suspect much of the electronics is fine. It would be good for someone wanting
backup cards.
You must be joking. Those cards are done. Any chip that is still
operational will likely fail upon or shortly after power is applied.
--
Will
I agree. Especially the ones heated high enough for the melted plastic
or scorch damage. A radiative and convective heat soak is pretty damaging.
Consider the flow temperature of the materials inside. Unless the fire
was flash fire, the entire thing would have been heated for some amount
of time (15 minutes minimum usually, to 45 minutes) due to response time
of the equipment.
Not evident in the photos would be possible contamination from either
fire suppressant materials or water to extinguish the blaze.
Like I said, Ethan is looking for a cabinet for an 11/70 stripped out of
such, and these probably are okay for that. Maybe some of the other
bits after inspectiong, but I'd not trust the boards up front. It would
be a project I'd want a solid shop of parts to do testing for every
board involved to certify they work.
Most people I know have one system in their basement, lab or garage, and
I'd personally not want to put boards from a source like this into such,
unless i had nothing to lose.
thanks
Jim
