A family member's house was damaged by their diesel car when it burst into flames while parked near the house. It also ignited two other cars parked
in the front of the house.
The front door and several front windows collapsed, funnelling the black smoke into the house. So most of the inside of the house was undamaged
except for a thick sticky coating of black soot coating everything exposed to the smoke.
All furniture and most everyday items in particular electrical items, white goods were dumped. The floor coverings, walls and ceilings striped.
It was said that the acidic fumes from the fire would damage the house wiring, plumbing and electrical goods, The fire occurred 13 months ago so now
the walls and floors have been renewed. The is no fire smell in the house, only a new paint smell.
One month ago a new oil fired heating boiler was installed with new shiny copper pipes. The copper pipes are not shiny now. They look dull like old
copper pipes.
A microwave oven has only been in the house infrequently over the last few months, but it stopped working recently. So opened it up to see why it had
failed. Lots of mild corrosion on most of the internal metal parts but nothing that would stop it working, or so I thought. There were odd looking
white lines on the coil of the cooling fan. When I touched the white lines, the turns broke. Apparently, the coil is made from aluminium wire so thin
that corrosion had reached even the core of the wire.
Below is a picture of the fan motor. The plain steel laminations are very rusty, and the copper shunts of the shaded poles are green with corrosion.
If the microwave oven really has only been in the house after most of the contaminated materials have been removed, it suggests the acid fumes
(probably HCl from the chlorinated plastics) are still diffusing out of the house materials and may damage lots more items in the future. Ouch! I hope
it's not a major problem for my family.
Sorry, I am having problems uploading the fan motor picture. i will try again later.
Pumukli - 18-8-2024 at 21:39
Browning of once shiney copper would not bother me: it does this in my home as well, no previous fire or anything like that.
But: aquarium pump (small compressor, vacuum pump), air sampling (bubbling air into distilled water for a while, preferably known volume), then
classic acid/base titration (if you are looking for HCl fumes). HCl would very well dissolve in water and after a few thosand liter bubbled through
one should be able to determine its quantity (and decide if it was a real concern or not).
Blank (control) sample taken from clean air (outside?)
Maybe it is not that simple but I do not see why it would not.Sir_Gawain - 18-8-2024 at 21:52
I think it’s more likely to be monoammonium phosphate from the fire extinguishers (if any were used). It hangs around, and will corrode any metal it
comes into contact with. After a kitchen fire in our house (in which dry chemical extinguishers were used) a steel light fixture nearby became covered
in rust. The powder is very fine, and floats everywhere.
[Edited on 8-19-2024 by Sir_Gawain]wg48temp9 - 19-8-2024 at 03:29
Thanks for the inputs, guys.
Browning of copper does not bother me either. But if it browns in less than a month, what will it do in one year or five years. See the corrosion on
the fan motor when I get it uploaded.
Yes, I like the bubbler idea. Evaporation of the water could be a problem but that can probably be easily managed. I don't they will go for that. I
few test bits of shiny copper pipe would be very straight forward and could be placed in different rooms in the house.
Apparently one house builder had problems with plaster beard (sheet rock) giving off corrosive fumes which did corrode copper wiring. It took a few
years before the problem was identified.correctly.
As far I a know no fire extinguishes where used inside the house though water was spayed on the front door and one or two windows and probably the
barge boards and guttering. The water did get into the ground floor. The broken windows and door were not boarded up for several days.
Also note three car batteries were destroyed with one of them having the plates exposed in a fan like configuration, no sign of the lead terminals or
internal lead interconnects or sulphuric acid. The sulphuric acid probably boiled off and may have entered the house in the smoke. I imagine that the
low vapour pressure of sulphuric acid at room temperature excludes it from the air in the house, even if some contamination remains in the house.
The twelve tires of the three cars also burned. Leaving only the internal wires behind. Its was suprising how many parts where plastic on the cars.
Fulmen - 19-8-2024 at 11:53
It should be possible to make a dry absorber from sodium hydroxide. It will absorb CO2 as well, so a direct titration won't say much. But chlorides
are simple enough to determine, same goes for most other relevant mineral acids. Sodium carbonate might work. PonderosaP - 5-9-2024 at 09:42
I'd suggest a swamp cooler if you have the budget or can make one yourself.
You'll get much faster results than a bubbler, as the air your moving through water is in the 100's of CFM(CMM?)/hour range, and the sample of
concentrate will be much bigger. With the inlet off you could manually top it up with distilled water once or twice.
As a bonus, once you figure out the contamination source you may be able to use the swamp cooler to scrub the air effectively until remidiation can be
accomplished. I use a homebuilt version to scrub the air when I have unpleasant vapor hanging around.
Doesn't burning diesel produce lots of NOx? Could the framing or organic material have been effectively nitrated? Nitrocresote covering
everything?
Zinc holds up to creosote treated wood for longer than HCl I imagine.
If you dissolved some metal salts in your test water you may be able to determine the culprit by observing color changes with either the fish bubbler
or swamp cooler.
Or maybe just blowing air past different metal samples over time.
Electrogalvanized roofing nails for zinc, bright framing nails for iron, aluminum can pop top, etc. At least this would be practically free and
silent, albeit slower and inconclusive.wg48temp9 - 5-9-2024 at 17:26
Sorry guys, I just noticed that my last massage was not posted. Apparently I forgot to click the Post button. But the three files were still in the
system??? Here they are:
I am now told the microwave oven was in a room at the back of the house during the fire. Which was not noticeably damaged, but most of the items and
fixtures were scrapped, and the room was stripped back to brick, bare floor and ceiling rafters. They saved the microwave oven as it looked undamaged.
They don't think the air quality needs to be tested. Hopefully, they want to regret that later.
[Edited on 9/6/2024 by wg48temp9]PonderosaP - 5-9-2024 at 17:59
Sorry guys, I just noticed that my last massage was not posted. Apparently I forgot to click 6he Post button. but the three files were still in the
system. Here they are:
That's a lot of corrosion very quickly.
I've seen a lot of old electronics and that's very unusual. Was this bought new?
Is there a bath fan in the house that exhausts outside?
It would have a lot of air flowing through it, with extra moisture. There is an identical shaded pole motor in a bath exhaust fan. Can you take
the cover off and look? Does it look similar?
If it does, you can't rule out contaminated water as a source. What is the water source? Do you live near any environmental sources of pollution
like hydrofracking oil wells or the Ohio River? Are you anywhere near east palestine?
What has been microwaved in there?
Is there a kitchen range exhaust fan? That may have a shaded pole motor, or higher end ones have silent DC fans. I'd like to see what condition a
similar fan is in nearby. More questions than answers, sorry.
Edit:
windings on the right are copper. I'd imagine the bearing(center) is fastened with a mild steel arm with a thin zinc plating. The white crumbles
are typical of chemical corrosion on zinc plated steel.
Was this micro in the house during the fire?
[Edited on 6-9-2024 by PonderosaP]
Edited again:
Is the housing around the motor aluminum? This looks like galvanic corrosion, I would bet money this microwaved was in the house during thr fire and
was hosed down completely during the fire.
Once the corrosion began the aluminum devoured the copper and zinc in the motor, aided by cycles of hot/cold moist/dry when someone in the house used
the micro to boil water for tea.
Only tangentially related to the fire and smoke that occurred last year.
[Edited on 6-9-2024 by PonderosaP]wg48temp9 - 6-9-2024 at 16:17
PonderosaP:
The fire occurred July 2023 in the front parking area of my sister's house, three cars were almost totally destroyed and a camper van, that usually
contained the microwave oven, was damaged. Anything made of plastic on the side of the camper van facing the three burning cars was distorted by the
heat but did not ignite.
Everything electrical in the house has been scrapped about one year ago.
The microwave oven was only used for cooking on long trips, a few times a year, for about 6 years. I am told it was purchased new. Note, when the oven
fan was working, no vapours from the oven chamber would have reached the fan. I suspect the owners are not certain where the oven was during the fire.
The metal bridge holding the bearing looks like aluminium, is non-magnetic or very weakly magnetic and soft. I suspect it would not be steel, as it
would bypass flux from the rotor. The windings of the coil are also aluminium, when cut they have a silver colour.
What flux is required to solder aluminium wire with tin solder???
Incidentally, the HT transform may also of one or more aluminium windings.
I live in the UK most of our water comes from lakes, so in general we don't have corrosive tap water. Now when I visited the outback of florida the
well water smelt like very rotten eggs. Having a shower in it was terrible. I guess the locals got used to it or had their smell cells knocked out by
the H2S LOL.
