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Fleaker
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Do you have any links for the teflon paint, I'm wondering how useful it would be for coating a fumehood?
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bio2
Hazard to Others
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Teflon®-S One Coat
The Teflon S #5 is the one you want
http://www.dupont.com/teflon/coatings/basic_types.html
The 6 Basic Types of DuPont Teflon Coatings
DuPont Teflon® industrial coatings can be used on carbon steel, aluminum, stainless steel, steel alloys, brass, and magnesium, as well as
non-metallics such as glass, fiberglass, some rubber, and plastics. Optimum adhesion is obtained by roughening the surface before applying the
coating. Except where specifically mentioned, most Teflon® industrial coatings require a primer coat.
1. Teflon® PTFE
PTFE (polytetrafluoroethylene) nonstick coatings are two-coat (primer/topcoat) systems. These products have the highest operating temperature of any
fluoropolymer (260°C/500°F), an extremely low coefficient of friction, good abrasion resistance, and good chemical resistance. PTFE is available
only in water-based liquid form.
2. Teflon® FEP
FEP (fluorinated ethylene propylene copolymer) nonstick coatings melt and flow during baking to provide nonporous films. These coatings provide
excellent chemical resistance. In addition to low friction, FEP coatings have excellent nonstick properties. Maximum use temperature is 204°C/400°F.
FEP is available in water-based liquid and powder forms.
3. Teflon® PFA
Like FEP, PFA (perfluoroalkoxy) nonstick coatings melt and flow during baking to provide nonporous films. PFA offers the additional benefits of higher
continuous use temperature (260°C/500°F), film thicknesses up to 1,000 micrometers (40 mils), and greater toughness than PTFE or FEP. This
combination of properties makes PFA an excellent choice for a wide variety of uses, especially those involving chemical resistance. PFA is available
in both water-based liquid and powder forms.
4. Teflon® ETFE
ETFE is a copolymer of ethylene and tetrafluoroethylene and is also sold under the Tefzel® trademark. Although not fully fluorinated, ETFE has
excellent chemical resistance and can operate continuously at 149°C/300°F. This resin is the toughest of the fluoropolymers and can be applied at
film builds up to 1,000 micrometers (40 mils) to provide a highly durable finish. ETFE is available in powder form.
5. Teflon®-S One Coat
These solvent-based liquid coatings are formulated with special blends of fluoropolymers and other high-performance resins to improve toughness and
abrasion resistance. Because the film components stratify during baking, most of the fluoropolymer properties (such as low friction and nonstick
character) are retained. The resins provide adhesion and abrasion resistance. These products can sometimes be applied to smooth, clean metal. Bake
requirements vary, depending on the specific coating, from 163°C/325°F to 316°C/600°F.
6. Teflon®-S Dry Lubricant
Dry lubricant coatings are special versions of Teflon®-S technology designed to provide lubrication under high-pressure/velocity (PV) conditions.
These products are solvent-based, one-coat systems that are usually cured between 260°C/500°F and 371°C/700°F.
Teflon Navigation
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Fleaker
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Thanks for posting that info. I think I'll go with PFA. But how to apply that to the laminate I'm using for the fume hood?
Hm, might have to rethink the construction materials. Perhaps I could use aluminum plate and roughen it up with emery and then bake on the PFA.
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DrP
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Sorry to drag this up again but I have some work to do with PTFE which will be destryed by fire. What are the current views of people as to the
safety of the PTFE decomposition products. I have heard and read mixed opinions. I want to be aure as I really don't like the sound of polymer flu
- even though it is only a tempory and non fatal illness.
Quote:
"DrP
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posted on 6-1-2006 at 10:33
I needed a high temp resistant polymer for a test I was doing - I thought about using PTFE - this would be great, however I believe that HF is
generated when the stuff burns and that it has a habbit of dissolving furnace linings apparently (being SiO2) .
This can't be very concentrated as I've heard the effects of being near to burning PTFE lead to something they call polymer flu (rather than death) -
like the flu but much much worse. I got some samples of a PTFE emulsion but decided not to go ahead with the experiments just in case.
Also - parrots and budgies kept in kitchins have died due to PTFE linings degrading from saucepans and frying pans giving small amounts of HF.
12AX7
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posted on 6-1-2006 at 11:32
Although I'm sure HF is present in small amounts, Teflon decomposition is mostly a hodge-podge of perfluoroalkanes and -enes, with varying amounts of
oxygen and hydrogen depending on conditions I'm sure. Nothing healthy at any rate.
Tim "
Here are some links to sites which list decomposition products and mention posible hazards:
http://www.bt-co.com/safety.htm
http://www.fluoridealert.org/pesticides/teflon.decomposition...
So what do you think??? Does anyone know for sure what the hazards are or are we still just guessing? Thanks.
PS - (Tim - sorry, I don't disbelieve you, it's just that I want to be REALLY sure I'm not going to get a lungfull of HF as the ventilation arround
the furnace is very poor and I will DEFINATELY get to sample some of the fumes given off I'm sure - usually alot of smoke - we have had a fume
hood installed over the furnace, but it is a bit crap and some smoke still gets into the room)
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Fleaker
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Just don't do it. I've accidentally melted down teflon coated aluminum products before and they reeked. I got slightly ill and a sore throat and I did
it outside. I suggest you burn off the coating in a large campfire before talking it to your furnace.
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neutrino
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This is an old post from RS. I think it is relevant here.
| Quote: | Posted by Purple Fire at RS
A friend of my fathers had a pretty close call with some fluorine gas. He owns a company that does something with ceramics (cant remember what). A
company that did teflon coatings (I think) went bust, and he bought a small furnace from them that they use for melting the teflon with. They set up
this furnace and fired it up, then realised that the temperatures they were using it at were significantly higher than those it had been used for with
the teflon. The layer of teflon that had biult up around the sides and floor of the furnace broke down and started giving off fluorine gas. The
workshop started filling with the gas and the guy noticed that the windows of his office had started to be attacked and were going cloudy. He got
everyone out and no one was hurt, but still... |
My guess is that fluorine wasn't actually reacting with the glass, but that some highly-reactive fluorine compound (possibly HF) was. If you do this,
definitely do it outside.
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Texium
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Thread Moved
19-11-2023 at 11:12 |
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