The WiZard is In
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acid/base proof wood lab bench top
Does anyone still do this? I remember using the K permangante,
Fe - Cu sulphate..... formula more than 50-years back. What I
remember best is that is was a really messy — a lot of
work project! Especially the thoroughly rubbing off.... part.
http://tinyurl.com/35gephc
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JohnWW
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If you want such a bench top to have a natural wood finish and appearance, you would need to coat it several times with a two-pot epoxy resin varnish
(brushes can be used only once). Marine supply shops, and the better paint and hardware stores, should have epoxy varnishes.
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Skyjumper
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Epoxy resin. Flinn Scientific's benches are heat proof, acid and base resistant. (although I have found that sodium hydroxide stains it, not badly
though, and it can be buffed out)
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Magpie
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I've never participated in making such a bench top, but I'm sure I used them back in the '60s and even into the '90s. These surfaces were black and
slightly lumpy. But they seemed to hold up well to the abuses of legions of students. Perhaps they were refinished during summer vacations.
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Chainhit222
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Formica plastic is decently chemical resistant and easy to apply to any surface.
http://en.wikipedia.org/wiki/Formica_%28plastic%29
Strong acids will fuck it up though, especially if warm. You need to clean them quickly.
I use some synthetic-rock material meant for bathrooms as the base of my fume hood, it gets somewhat discolored by strong acids but that does not
bother me. And I found that epoxy (at least the home depot brands for painting floors, both one part and two part) is attacked by fuming (95% or so)
nitric acid.
[Edited on 7-7-2010 by Chainhit222]
[Edited on 7-7-2010 by Chainhit222]
The practice of storing bottles of milk or beer in laboratory refrigerators is to be strongly condemned encouraged
-Vogels Textbook of Practical Organic Chemistry
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Panache
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its nice and forgiving wood. I currently use some veneer (i think its oak) that has been Japan blacked to a solid black then waxed, i guess i retint
it every six months or so, birch edging in natural offsets it nicely, only takes about 15minutes. Every now and then i need to replace one of the
sections if something silly happens, like piranha is spilt all over it, for weeks after that accident i would have people saying 'have you had a
fire?' because it smelt burnt .
That said if i had to actually pay normal cost for the sheets i would not get them. luckily i have two pallets of them a friend demo'ed out of a high
end law firm's library. 5 years old, they renno'ed the entire place, chucked everything, half my lab i couresty of Freehills.
I think i've said it before though i previously have used timbers that are only oiled with vacuum pump oil, no prizes for how i figured out to do
that.
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leu
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One good way to construct such a lab bench is to cover the entire surface with about 3 mm (.125 in) of epoxy resin and finish it with
epoxy-polyamide paint sold for refinishing bathtubs 
Chemistry is our Covalent Bond
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Sedit
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I planned on coating mine with the clear epoxy the guy told me they use for bar tops. He said they use it because its hard and durable but I still
have to check its acid/base resistance before buying it. Anyone ever use a one part clear epoxy for there top?
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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peach
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When our secondary school had a lot of building work done, they threw out all the wooden benches and replaced them with very expensive polymer
surfaces that were supposed to be invulnerable to chemical attack.
Needless to say, iodine didn't think so. And they never couldn't get the stain out.
Lab suppliers sell a type of disposable paper you can use for your work top.
The worst spills I have are of solvents or anything containing iodine. The solvents rot finishes and iodine's ability to stain things is nothing short
of magical. Even after I've washed something that's had iodine on it, I'll put it down and find vapours from it have managed to stain something else.
Depending on how careful you are, you could put a sheet of tempered glass on the surface for really good chemical resistance.
Another option would be to use a Belfast sink. £75 reclaimed, but heavy ceramic. You could use a taller one and get creative with an angle grinder
and diamond blade, and build a hood around the cut edges if you want to get fancy. Added bonuses, if anything bursts or spills, it's not only staying
in one place, it's going down the plughole - which can be connected to some form of recovery container. It's also going to contain a fire.
[Edited on 15-7-2010 by peach]
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zed
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In years gone by, the accepted wisdom was, that if you absolutely must have maximum chemical resistance.....use wood. Refinish it occasionally, if
you must.
Does an epoxy coating actually help? I'm concerned it might be flammable under some conditions.
[Edited on 15-7-2010 by zed]
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peach
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A fairly simple observation here is that all chemically resistant glassware is borosilicate glass, not wood.
Sorry to be a gimp, but that's crystal clear fact <----- another poor joke. 
If I spill KOH on the wooden surfaces in the kitchen it'll mess them up, and that's just me doing the dishes.
[Edited on 15-7-2010 by peach]
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The WiZard is In
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Them that work with radio-chemicals use strip-able coatings
just peal it off when done did.
Whatever happened to good old soapstone? Extremely chemical
resistant, well not HF. Mechanically ... it sucked.
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Fleaker
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They make a nice PTFE film that has an adhesive foiled-over backing. It's not super expensive, probably $60/m^2 IIRC. I don't remember my source, but
you can quite easily stick it onto 1" composite board and fold it over and pin to the underside of the board. Then you have a surface that is
virtually invulnerable to acids and bases and no longer flammable (it's more tolerant of heat than the underlying wood).
Also cleans really well :-) Probably forensically well if you're cleaning with Caro's acid...
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
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Panache
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Quote: Originally posted by Fleaker  | They make a nice PTFE film that has an adhesive foiled-over backing. It's not super expensive, probably $60/m^2 IIRC. I don't remember my source, but
you can quite easily stick it onto 1" composite board and fold it over and pin to the underside of the board. Then you have a surface that is
virtually invulnerable to acids and bases and no longer flammable (it's more tolerant of heat than the underlying wood).
Also cleans really well :-) Probably forensically well if you're cleaning with Caro's acid... |
Too slippery and too soft IMHO, however i may soon be able to try my idea i have had for several years, actually like 15 years, as i just bid online
for a thermal spray unit, cement sheet with a nice coating of glass over it, up the splashback etc, no-one should hold their breath though.
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