asbestos in Emerson....remove it?
Steve
Over the weekend I picked up a cute little Emerson radio.
Its an AA5 in an Ingram (wood) cabinet with 4 station pre-selector
buttons on top. Can't find a model number on it.
Under the chassis, and on one side, there is what I think
is asbestos stapled to the inside of the cabinet.
Doesn't seem to be flaking off. Should I leave it or
remove it (carefully)? What have other done?
Steve
nesesu
Once the surface and edges are soaked with the latex and it has cured,
there will be no bits of asbestos fibre coming off and it is prefectly
safe.
It is not safe to remove it unless asbestos handling procedures are
followed, and in any case it IS there for a purpose. It is supposed to
protect the wood case for overheated components [resistors, tubes,
etc.] so you would need to replace it with something equally effective.
Neil S.
John Goller, k9uwa
says...
baggie.. also carefully wipe out any loose fibers with damp rag..
put rag also in baggie ... wear mask ... don't breathe the stuff
while removing it..
John k9uwa
Mark Oppat
The cases of abestosis were from workers who dealt with the stuff
EXTENSIVELY over a long period of time!
Mark Oppat
"Steve" <za...@sonic.net> wrote in message
news:44b26854$0$96208$742e...@news.sonic.net...
AuroraOldRadios
In any case, I would use a method that causes the least disturbance of
asbestos material. Check this website for the risks.
http://www.airborneasbestos.com/
Mark Oppat
Mark Oppat
"John Goller, k9uwa" <k9uwa...@THISarrl.netSTUFF> wrote in message
news:qlusg.829665$084.386310@attbi_s22...
Peter Wieck
Latex is not a suitable binder if heat-resistance is at issue. The
technical term for the process is "encapsulation" and the idea is to
bind the fibers in place and to each other so that they do not become
airborne... the only time asbestos is known to be dangerous.
My process is to use Ambroid Cement cut 1:1 with acetone. Soak it into
the asbestos, allow to dry, soak again. This process is effective, and
when cured retains the resistance of the asbestos against heat. There
is a much longer description complete with cautions and caveats
elsewhere in the archives. But suffice it to say that all the proper
precautions should be observed for Acetone, Asbestos, work area and
so-forth. This includes respirators, working outdoors and so-forth.
As to removal and disposal... that is an interesting situation. It
takes only one (1) fiber to cause asbestosis given enough time, and
although the chances are slim why lean into the punch? And if one
smokes, those odds increase hugely. Better it should be left in place
and rendered inert.
Peter Wieck
Wyncote, PA
Steve
now. That way it will retain its originality and heat
shielding capability.
Steve
Ken G.
possible trouble .
James Sweet
Just leave it alone, despite the hysteria I know guys who crawled around
in the stuff when they were younger. As with PCB's there's a lot of
undeserved paranoia, just don't eat the stuff or bathe in it. Left
undisturbed it's unlikely to ever cause problems.
John Goller, k9uwa
mop...@comcast.NOSPAMnet says...
>
>
>uh, John, do you still smoke?
>
>Mark Oppat
Yup I know... its gonna kill me faster than the asbestos will..
I don't take the stuff out for me... I take it out for some of
the non-collector idiots in some cases that I sell radios to...
at least I carefully take it out and dispose of it... some fool
might decide to rub it and breathe the stuff...
At least the pipe I am smoking probably won't kill me quite as
fast as the Cigarettes I was smoking...
If I had known I would live this long I would have taken better
care of this old Bod!
quote from one of my older buddies!
John k9uwa
John Goller, k9uwa
good...@webtv.net says...
>
>
>I remove every one i get and rid anyone else in the future of its
>possible trouble .
>
the respirator...
John k9uwa
Mark Oppat
NUTS! There, I said it...!
NOBODY will ever sit there and abrade the pad in an AA5 radio and inhale it
and get asbestosis and die and sue you. Wont happen. Now, removing it
creates a heat/burn hazard you are creating. I dont like that.
LEAVE the pads alone. If loose in there, staple them up tight. Please,
get off this "asbestos is a great evil" kick, you are just perpetuating the
myth created by several NY area lawyers who twisted some data into what was
probably the largest noose in history which strangled and bankrupted
thousands of schools for absolutely NO good. In fact, the contractors who
removed the stuff made a FAR more dangerous hazard (they, and the guvmint
will never admit this of course).
Asbestos is dangerous if inhaled in large doses. Mainly its the BLUE
asbestos that is the most dangerous. It was used in many industrial
applications, and auto brakes. I would not like to live near a busy
intersection where brakes are applied constantly.
BTW, asbestos is accepted freely in any landfill. It is rock, after all.
Mark Oppat
"Ken G." <good...@webtv.net> wrote in message
news:26972-44B...@storefull-3233.bay.webtv.net...
James Sweet
> can I say you guys are nuts and we can still be pals? OK, YOU GUYS ARE
> NUTS! There, I said it...!
>
> NOBODY will ever sit there and abrade the pad in an AA5 radio and inhale it
> and get asbestosis and die and sue you. Wont happen. Now, removing it
> creates a heat/burn hazard you are creating. I dont like that.
>
>
Friend of mine started collecting old streetlights when he was a kid
(yes, and some people say collecting old radios is weird too), his dad
was paranoid about PCB's and made him remove all the ballasts and throw
them in the trash, hence the PCB's contained in the capacitors ended up
in a landfill and likely are seeping into the ground somewhere. Had they
been left alone, they'd still be sealed safely inside capacitors in old
fixtures mounted on the wall in the garage harming no one.
PCB's are not good for you, neither are cheeseburgers or beer, but in
either case exposure to small amounts won't cause a person to drop dead.
Same goes for asbestos, don't grind it up and snort the dust or shred it
and stuff your pillow. Another friend of mine who's in real estate tells
me the asbestos removal guys are running out of asbestos to remove, now
they're busy villanizing formaldehyde-containing fiberglass insulation,
it's always something. Sorry but I don't buy the paranoia, it's all too
easy to focus on little specific things and ignore everything else.
Brian McAllister
Goller, k9uwa) wrote:
>>uh, John, do you still smoke?
>>
>>Mark Oppat
>
>Yup I know... its gonna kill me faster than the asbestos will..
Either that or it will help the asbestos kill you faster. They seem
to pack a real one-two punch.
Brian McAllister
Sarasota, Florida
email bkm at oldtech dot net a...@hope.thespambots.die
Mark Oppat
Mark Oppat
"James Sweet" <james...@hotmail.com> wrote in message
news:MhEsg.14606$Wh7.9966@trnddc07...
John Goller, k9uwa
mop...@comcast.NOSPAMnet says...
>
>
>Uh, you forgot the MOLD industry! Its the new contractor cash cow.
>
>Mark Oppat
fast becoming the weapon of choice by the local gestapo
"Neighborhood Code Enforcement Officers"
One of my renters recently had the Code Guy stop to see her... her
Lawn Service Guy had fired up his Lawn Mower at 7:55 AM ... at least
according to the pain in the ass next door....
Now I can also get a ticket for running my lawn mower after 9 PM ... but
its OK to blow up fireworks until 11 PM .. except July 4th when I can
blow them up until midnite!
John k9uwa
barryh
grater style which was also common in bakelite or catalin. I didn't
see any asbestos in that one. I have another, which has an all wood
front, but the same round dial with the "pudgy" pointer. I haven't
opened that one up yet.
I posted a similar question -- what to do about the asbestos -- a
couple of weeks ago in connection with two 7G Transoceanics (bombers) I
have which need work. The asbestos laps over the edge of the chassis
shelf on those and one, in particular, is flaking. On closer
inspection, I saw quite a bit of loose fibers in the case. I
immediately repacked the thing as I wasn't set up to deal with it.
I don't know to what extent it's all hyped up, but, from the look of
the stuff, it can really fly around, is light enough to be inhaled, and
from the way it clings to the inside of the cabinet, I can just picture
the stuff digging into the inside of a lung and staying there
permanently. Being a smoker still and paying for the priviledge of
killing myself, I'm not a health nut, but this stuff is another matter.
Yeah, there are those lawyers' commercials -- mass market ambulance
chasing. Incidentally, I see a number of them with fine print whereby
they can't practice in NY - -Mass or NJ based.
Anyway, I'm inclined to go with Peter Wieck's procedure, but would like
some step-by-step detail. I also need to clean up the loose fibers.
One way might be to lift them with duct tape or something tacky. I
happened upon a federal asbestos-handling site where the also
recommended not to disturb the stuff if it's secure and to encapsulate
or cover in place. One of their recommendations was to cover with
plenty of duct tape. There probably should be a US Dept of Duct Tape,
and maybe an independent "Commission of Duck Tape (quack quack)".
Of course, now they say one whiff of secondhand smoke will be enough to
do you in -- but what about that bus that you drove behind for a mile?
Barbecue? Wildfires? I think the only solution is a full-time,
full-body hazmat suit, complete with inlet and outlet fittings for
pumping in filtered water -- for bathing. You wouldn't want to take it
off in the bathroom -- there are a lot of hazardous chemicals in there.
But, seriously, those loose asbestos fibers really look nasty.
Barry
toxcrusadr
barryh wrote:
The asbestos laps over the edge of the chassis
> shelf on those and one, in particular, is flaking. On closer
> inspection, I saw quite a bit of loose fibers in the case. I
> immediately repacked the thing as I wasn't set up to deal with it.
I'd have to say that this one needs removing.
I think all of you have a piece of the truth, and the answer for me is
a combination of all of it. If it's in good shape, I'd leave it in
place, maybe seal it if I felt like it but finding and buying Amberoid
cement (whatever that is) would be yet another time consuming chore for
a guy who does 2-3 radios a year if that. A hand sized piece in good
shape sitting on the shelf is not going to be a significant risk.
Barryh's, I'd remove outdoors wearing a good mask (a real rubber seal
mask with micron cartridges, not the 10 cent variety), dispose in
double packaging, and wipe down the cabinet with a wet sponge.
BTW, an unasked question: for those of you who always remove them,
what to you REPLACE them with to prevent cabinet warping and burning?
Tox
Peter Wieck
RANT WARNING RANT WARNING RANT WARNING
Asbestos ain't nohow a legend, over-hyped, or over cautioned. It is a
dangerous material that can manifest its effects as much as 60 years
after a _SINGLE_ exposure, or only a few weeks after a large exposure.
Smokers are far more prone to its effects, but anyone, anywhere can be
affected if exposed. I have spent the last 35 years in or around the
construction industry, and have seen my father-in-law (multiple
exposure, smoker) a neighbor (single exposure, non-smoker) and quite a
number of workers (mostly smokers) die from the stuff over that time.
Known dangers are only from inhalation. Tests show it may be eaten,
drunk, rolled in, made into gloves, clothing, whatever. As long as it
stays out of lungs.
So, let's look at the situation from that perspective. The point is to
keep it out of lungs. Any lungs, any where.
Premise: You have a radio containing asbestos. That radio is under your
control. You have four legitimate (for lack of a better word) choices.
1. Get rid of the radio.
2. Get rid of the asbestos & keep the radio.
3. Render the asbestos harmless & keep the radio.
4. Do nothing, and the radio remains a shelf-queen.
The first merely passes the problem on to someone who may or may not
follow some of the advice rendered here and just dump the stuff in the
normal trash, remove it in his/her basement (potentially exposing kits,
cats, sacks and wives) or worse.
The second assumes a stringent level of care and precautions that are
costly and troublesome... and proper, sure disposal. That last, at
least legally, is not typically within the means of most of us
excepting at a significant expense.
This, to me, represents the best option. And if this can be done in a
way to maintain the purpose of the material in the first place, even
better. The problem is _solved_ and all the peripheral requirements are
eliminated.
The fourth is an option. I don't like it personally, but it is
infinitely better than messing with the stuff without the proper
precautions or results.
So, ignoring the Polyannas and the Cassandras, the choice I would make
would be based on the long-term, and would I have _that_ radio in the
same room with the grandchildren. Kinda-sorta makes the decision much
easier to make and the choices far more limited.
Ambroid (wood) Model Cement ( http://www.ambroid.com/Ambroid.html#1511
) may be purchased at any art-supply, hobby-shop, most hardware
stores, and on-line. It is cheap, as is acetone. It is only one of
several similar materials that will do approximately the same job, I
choose it because of its designed-in heat resistance when cured. But
Duco Cement is a very similar product equally easy to find. I am not
sure of its heat-resistance, however. Nail lacquer would be unsuitable
as many formulations are highly flammable (nitrocellulose).
END RANT.
Peter Wieck
Wyncote, PA
toxcrusadr
Peter Wieck wrote:
> GRUMP!!!
>
> RANT WARNING RANT WARNING RANT WARNING
> END RANT.
>
Ok, but what do you replace it with to prevent cabinet damage?
I'm thinking Twinkies, just the foamy part, with the filling removed.
Tox
Bill Sheppard
Not disputing your analysis/ Grump/Uber-Rant.<g But what
about all the asbestos in brake linings? While it's being phased out in
newer equipment, there's decades worth of it still out there. Seems like
mechanics in auto shops would be particularly vulnerable from doing
brake jobs. I shudder to think of all the dust-laden brakes i've changed
in years past with no precautions taken. I should be keeling over any
time now.
Bill(oc)
Peter Wieck
toxcrusadr wrote:
> Ok, but what do you replace it with to prevent cabinet damage?
>
> I'm thinking Twinkies, just the foamy part, with the filling removed.
>
> Tox
Biting my fingers as hard as I can to prevent snippy comments from
coming through...
I DO NOT remove the asbestos, so I DO NOT have to replace it. I "SAFE"
it so that it can do no harm yet continue to function as-designed.
Since I am still in a semi-rant mode, please excuse the tone.
Peter Wieck
Wyncote, PA
Peter Wieck
Bill:
A common question: But if... "they" don't experience a problem, it must
be harmless, right?
Asbestos must be 'friable' to be harmful. That is in particles small
enough (< 0.4 microns, typically) and *LIGHT* enough to become airborne
and small enough to get into the lungs. Typically the asbestos found in
brake linings is quite heavy, thermally compromised (bound to other
materials due to manufacturing binders, heat or partially fused), or
any of several other reasons for it to be less volatile than asbestos
*insulation*, the nature of which is to be loosely bound fibers...
thereby increasing thermal insulation properties.
That is not to say mechanics, especially those who use air-hoses are
not at potential risk They are and there are well-documented cases due
to exposure to brake-lining material. But relatively few considering
the millions of exposures. Similarly, epoxy-bonded "Transite" (vs.
cementicious-bonded) is still in somewhat common use in laboratory
applications and acid-safes and such as even when cut or abraided, the
fibers tend to be bound to the binding materials and therefore not
friable.
Peter Wieck
Wyncote, PA
Carter, k8vt
> GRUMP!!!
>
> RANT WARNING RANT WARNING RANT WARNING
>
> Asbestos ain't nohow a legend, over-hyped, or over cautioned. It is a
> dangerous material that can manifest its effects as much as 60 years
> after a _SINGLE_ exposure, or only a few weeks after a large exposure.
> Smokers are far more prone to its effects, but anyone, anywhere can be
> affected if exposed.
Peter,
I've generally got to agree with you. Asbestos is indeed nasty stuff
(although some may debate about the asbestos sheets in radios).
However, let me add the following warning:
Many people here on this NG are somewhat "electrically oriented", which
is to say that some may do their own electrical work (as in house wiring).
If you are in that category and go into the attic of a house that has
"Zonolite" insulation (looks a little like popcorn), DO NOT TOUCH IT !!!
This is an "expanded" form of a mineral that is a great insulator but
also contained a lot of asbestos. It was used extensively as a home
insulation in the 50s-60s-70s.
This stuff is *unbelievably* NASTY. Do not take my word for this but
rather refer to the following book:
"An Air That Kills" by Andrew Schneider, call number 363.1791 S
Like you, I know some electricians that used to swim in this stuff, have
been diagnosed with mesotholemia and are essentially waiting to die...
:-(
P.S. The book also addresses the issue of asbestos in brake linings.
Bill Sheppard
>...even when cut or abraided, the fibers
Aha. Makes sense. So even if copious amounts of brake dust are inhaled
(as in a brake shop), each individual dust particle is actually an
aggregate that is not carcinogenic like isolated asbestos fibers would
be. Right?
oc
Ken G.
might have asbestos . The asbestos radios dont have any different parts
than the other 97 radios .
Asbestos is a known hazard May some of it be minor . I firmly stand on
safely removing it away from others reach . Most people remove hazards
from other peoples reach . I will never understand this ``cover up a
hazard with goo`` .
Peter Wieck
Ken:
It is not "covered", it is "encapsulated". Essentially, the fibers
absorb, are bound, and are surrounded by material that will prevent
them from becoming exposed or airborne in a harmful form. Asbestos is
dangerous in a single mode. If that mode is prevented, it is quite a
useful material. Much as many of the items under your sink or inside
your medicine cabinet or in your garage. Such as: aspirin, pine-oil
cleaner, anti-freeze, insect spray, weed killer, and so forth, too
numerous to mention.
As to removal, and all kidding aside, if you are using the proper
techniques, the proper materials, and the proper disposal methods, more
power to you. But short of having a relationship with an abatement
contractor such that you have access to licenses, disposal sites and
the various forms and such... Well, you get the picture.
Peter Wieck
Wyncote, PA
Peter Wieck
Something like that. The better term would be 'less' carcinogenic, as
there is always a chance that the occasional few bare fibers of the
proper size (< 0.4 microns) could become airborne without any attached
aggregates. And it must also be noted that dust raised by compressed
air of particles easily discerned by the naked eye does not fit that
mode typically. But there are (very few) cases of brake-shop workers
contracting asbestosis in several forms... but far less than ship
workers, insulation workers, even asbestos abatement workers.
Peter Wieck
Wyncote, PA
Stephanie Weil
Ken G. wrote:
> I remove every one i get and rid anyone else in the future of its
> possible trouble .
I was repairing a Bendix for a co-worker sometime last year. There
was a pad of asbestos glued to the inside of the plate covering the
bottom of the chassis.
While debating what to do with it (on this forum), I took the plate
outside and put it in a transparent bag. Shook the plate a bit and the
clump of crap fell off and crumbled.
Wiped the plate with a damp paper towel. Problem solved.
--
Steph
barryh
Peter Wieck wrote:
> As to removal, and all kidding aside, if you are using the proper
> techniques, the proper materials, and the proper disposal methods, more
> power to you. But short of having a relationship with an abatement
> contractor such that you have access to licenses, disposal sites and
> the various forms and such... Well, you get the picture.
The two "bomber" Transoceanics I have, have the stuff lapping over the
chassis shelf where the asbestos is particularly crumbly and flaky. I
have not attempted to remove the chassis as yet. I just know it will
fly around and who knows what's under the chassis in amongst the
circuitry? (How do you get rid of that? Vaccum??? Air blast it
outdoors?)
Years ago, I used to make wooden models and Ambroid was popular. I
haven't seen it around lately -- nor Duco cement -- in local stores,
but, as I recall, it was amber/orange in color -- and I thought it was
also a nitrocellulose product. At any rate, I wouldn't have thought it
was particularly heat resistant. Offhand, I might have gone for epoxy
as a sealant, but that would be difficult to work with.
Anyway, Peter, it would be helpful if you gave us a step-by-step --
really down to the nits -- as to how you go about it. ... something
like this -- and I'm second-guessing:
1. Keep radio in plastic bag.
2. Take outside and stay upwind of it -- check what's downwind
3. Put on filter mask (type/model?)
4. Carefully remove from bag, Close up bag and tape.
5. Remove chassis and set aside --
6. Pick up any loose particles .... How? Tape?
7. Mix x parts Ambroid with y parts acetone.
8. Apply to asbestos -- (How -- brush? Pour it on and spread around?)
9. How to deal with edge overlap -- extra coats?
10. How many coats?
11. Allow X hrs/days to dry.
12. Wrap up and discard brush.
As long as we've gone this far on this topic, might as well go a bit
further.
Another question: What happens after the Ambroid coating is set? Is
it thin enough to soak into the asbestos, so that when you go to
replace the chassis, put the screws through, etc. that, even if some
bits come off they will be aggregated in the glue? I might think that
the stuff is still fluffy under the coating whereby if a piece breaks
off, particularly where it slops over the chassis shelf, "friable"
particles could still be released.
I noticed an ebay auction where the seller mentioned that the shelf was
"covered in cardboard for personal safety." That didn't sound very
confidence-inspiring. However, an extra step might be to glue some
material over it. It would have to be thin -- maybe "fish paper" --
that gray stuff?
Barry
Bill Sheppard
>It is not "covered", it is "encapsulated".
>Essentially, the fibers absorb, are bound, >and are surrounded by
material that will
>prevent them from becoming exposed or
>airborne in a harmful form.
I'm showin' my ignirance again here, but when the "encapsulating" agent
has soaked into the asbestos matting and cured solid, does that not
defeat the heat-insulating property of the matting?
Seems like the preferred method would be to "envelope"
rather than "encapsulate". Maybe an envelope of metalized mylar or
similar 'skin' to seal the stuff in?
oc
Peter Wieck
Bill Sheppard wrote:
> I'm showin' my ignirance again here,
Not really, these are not very intuitive terms, but they are accurate.
but when the "encapsulating" agent
> has soaked into the asbestos matting and cured solid, does that not
> defeat the heat-insulating property of the matting?
> Seems like the preferred method would be to "envelope"
> rather than "encapsulate". Maybe an envelope of metalized mylar or
> similar 'skin' to seal the stuff in?
> oc
Encapsulation: Concrete is an "encapsulation" of several types of
aggregate in a cement paste, with the cement being ~15% by-volume of
the total, excluding the water. Sand and gravel (inert, non-binding
materials) make up the remaining 85%. The nature of concrete becomes a
combination of the materials included within it.
Envelope: A cute birthday card such as one would give one's SO is
"enveloped" in an outer covering, which will often equal in volume
exceed by area the enclosed contents. And the nature of the contents is
unchanged should the external coating be removed, and the nature of the
envelope is not affected by its contents.
Now that we have defined-by-illustration the intent, the Ambroid Cement
*CUT 50% with acetone* is the "cement paste" that then binds the
aggregate (asbestos fibers). Ambroid is formulated to resist heat, hot
liquids and hot solvents (it is designed to resist a combination of hot
methanol, nitromethane and castor-oil, after all) without failure.
Asbestos fibers are quite absorbent as typically formulated in this
application, so the thinned glue will penetrate well. In the case of
the asbestos, the actual by-volume of material added will be
considerably less than 15% when cured, but the aggregate will be fully
encapsulated.
Peter Wieck
Wyncote, PA
Peter Wieck
http://www.geocities.com/wa2ise/radios/repair.htm gives a very
slightly edited version of my technique.
But to clarify:
My preference towards Ambroid is that it is formulated against heat and
solvents when-cured. It is also commonly available. Our local Home
Depot stocks it, for instance. The color helps identify to any future
owner that your representation is accurate* (see below).
I mix up the liquid and pour it over the mat, then using a small, soft
brush spread it around the corners, edges and any cracks so as to be
sure to soak through. The first application is poured until the surface
remains shiny and stops soaking. THEN it is allowed to cure. Then the
second application (usually much lighter), then cure again.
*Leave a note in the radio somewhere stating what you have done (see
above).
Covering over asbestos does two (bad) things:
1. It introduces a material that is fundamentally different in nature
from the asbestos.
2. It does nothing to prevent accidental mechanical disturbance of the
asbestos, or to prevent problems if disturbed.
Peter Wieck
Wyncote, PA
toxcrusadr
Carter, k8vt wrote:
> "Zonolite" insulation (looks a little like popcorn), DO NOT TOUCH IT !!!
>
> This is an "expanded" form of a mineral that is a great insulator but
> also contained a lot of asbestos. It was used extensively as a home
> insulation in the 50s-60s-70s.
>
> This stuff is *unbelievably* NASTY. Do not take my word for this but
> rather refer to the following book:
>
> "An Air That Kills" by Andrew Schneider, call number 363.1791 S
>
There is a lot of information out there, this Zonolite thing blew up in
just the past couple of years. Do a Google news search on it, or the
NY Times, or look at EPA.gov for fact sheets. Note there was also a
lot of expanded mica (vermiculite) used in potting mixes :-o Most of
the Zonolite came from Libby, MT where the whole town practically has
lung disease.
Regarding Peter's comment on removing the asbestos - and I'm not
advocating leaving or removing here - you don't need abatement
contractors, special disposal sites or anything like that. Small
amounts like you would find in a radio can be disposed of in the trash
by double bagging and labeling ASBESTOS. This is allowed under Federal
law for residences, up to 35 sq. ft. of material I think. If you are a
business, different story.
Tox
Bill Sheppard
>Asbestos fibers are quite absorbent.... so >the thinned glue will
penetrate well. In
>the case of the asbestos, the actual
>by-volume of material added will be
>considerably less than 15% when cured,
>but the aggregate will be fully
>encapsulated.
Understood. But again the question (to repeat): When the ambroid has
soaked into the asbestos matting and cured, does the aggregate become
more heat-conductive and lose insulating efficiency? Or does its
insulating efficiency remain unchanged from that of the the raw
asbestos?
Take brake linings which are (were) an asbestos-containing aggregate.
Their primary design criterion is not to insulate, but to operate at
high temperatures without mechanically degrading.
oc
Peter Wieck
Bill:
Point is that "insulation" characteristics and "high temperature"
characteristics are quite similar (but emphatically not identical).
Ambroid *does* resist high temperatures, not nearly as well as
asbestos, but certainly better than similar formulations made without
that requirement. So, the short answer is that the behavior of the
asbestos *will* be reduced somewhat over the bare material, but at the
same time, the film-strength of the material will be greatly enhanced.
So, the ultimate performance as insulation will likely be very similar
after treatment as before. But in terms of pure *fire* protection,
plain asbestos will be best. Obviously. Against warping, charring or
similar, it will be a close-run thing.
Peter Wieck
Wyncote, PA
barryh
Peter Wieck wrote:
> Point is that "insulation" characteristics and "high temperature"
> characteristics are quite similar (but emphatically not identical).
> Ambroid *does* resist high temperatures, not nearly as well as
> asbestos, but certainly better than similar formulations made without
> that requirement. So, the short answer is that the behavior of the
> asbestos *will* be reduced somewhat over the bare material, but at the
> same time, the film-strength of the material will be greatly enhanced.
> So, the ultimate performance as insulation will likely be very similar
> after treatment as before. But in terms of pure *fire* protection,
> plain asbestos will be best. Obviously. Against warping, charring or
> similar, it will be a close-run thing.
>
Hi Peter (and list)
Many thanks for the details. It would be nice if this were all
published on a web site or two.
Thinking about it further, it seems there is an inconsistency in the
manufacturers' application of asbestos (or at least Zenith's) and I
wonder if you or someone could explain. The 7G's have the coating and
maybe some 8G's -- I don't recall. Plus, this thread started with
someone asking about a wooden Emerson. Apparently, the asbestos under
the chassis was a "sometimes" thing from the late 30's through maybe
early 50's.
Just sorting out the Transoceanics: The 7G's had hot-running rectifier
tubes as did the 8G's, though the later ones used the minature version.
Starting with the G-500's, they went to selenium rectifiers.
Otherwise, all the other tubes were cool running 1.5 volt filament
types, whether locktal or miniature. The 8G's had the highest tube
count (8). As far as under-chassis components are concerned, perhaps
they moved from wax covered caps to molded plastic (black beauties)
over that early time frame.
If the concern were either heat/warpage and/or possible fire
prevention, what caused them to use asbestos earlier, then discontinue
using it -- whereby most of the 8G's and all later models (G-500, H-500
and (x)-600's) just have raw wood? In other words, they apparently
stopped using it in/around 1948, but I don't see much difference in
heat/fire factors between the models going forward. I doubt if the
hazards of asbestos were identified by then -- or were they?
Barry
Peter Wieck
barryh wrote:
I doubt if the
> hazards of asbestos were identified by then -- or were they?
>
> Barry
"White Lung Disease" has been known and indentified for as long as
asbestos has been mined. The secondary effects started to be noticed
and identified shortly after WW-I, and more specifically after WW-II,
and in the 50s first amongst construction workers spraying
fire-proofing on steel buildings.
So, yes, they were. Did that concern drill down to the consumer level?
Not hardly as one could still purchase asbestos-based furnace-cement
OTC at any hardware store into the 70s.
Peter Wieck
Wyncote, PA