Cavatica - 3-7-2017 at 10:37
Any good reason why I could not use a couple of ply of PTFE foil for walls for my fume hood, as opposed to glass or some other suitable rigid
material? It would be a dream in a mobile lab scenario. Please shoot me down if this is a dumb suggestion. Thanks.
macckone - 3-7-2017 at 19:57
Yes you can buy PTFE or other fluorinated polymer sheet with an
adhesive backing. However, glass is cheaper for most purposes
an easier to obtain. Acrylic sheet costs more but doesn't shatter
like glass, it is readily available but may react with solvents.
Solvents can also cause the adhesive backing to stop adhering
with PTFE sheeting.
Some professional fume hoods use laminated glass with acrylic
anti-shatter layer, much like american windshields.
There are any number of paint type coatings for walls of a fume hood.
Automotive engine paint is resistant to most solvents but
requires heat lamps to cure. You can also buy ptfe based paints.
They also require baking to cure.
http://www.orioncoat.com/coatings/ptfe-and-non-stick/
Cavatica - 4-7-2017 at 01:14
Thank you, that was quite comptehensive, and provides a good starting point.
Praxichys - 4-7-2017 at 17:07
I like to go with a more disposable route. I made a wood frame and use quarter-inch plywood for the inner surfaces. Some plain white house paint
finishes the setup. Most stains wash off; those that do not can simply be painted over at regular intervals. On the rare occasion that damage occurs,
replacement is easy and inexpensive. Most often the damage is heat/fire related (like leaning something hot on it or having a burner flame blow in the
exhaust fan stream and scorch the wall), so I would think having to replace PTFE sheeting in that case would be unnecessarily expensive for an amateur
setup.
Cavatica - 6-7-2017 at 06:33
I see your point, however I don't want to skimp too much on something like this. Also, I like the idea of a flexible foil structure that would be more
likely to absorb the kind of pressure that might otherwise send shards of wood, metal or glass flying everywhere in case of an accident involving a
sudden expansion of gas.
macckone - 23-7-2017 at 11:17
In the other thread on fume hoods, someone pointed out that the
fume hood is supposed to be flame retardant. That limits
the inner surface to glass, gypsum board or other flame retardant
materials. Some epoxies are flame retardant or have additives
that can make it flame retardant. Polypropylene, polyethylene
and acrylate plastics are not flame retardant unless something
was added.
PS. engine paint and teflon paint are totally flame retardant.
So those recommendations still stand.
[Edited on 23-7-2017 by macckone]