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bfesser
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A few days ago, while preparing wood sash windows to accept <a href="http://en.wikipedia.org/wiki/Glazing" target="_blank">glazing
putty</a> <img src="../scipics/_wiki.png" />, I spilled a large volume of oil-based primer on my hands. Unfortunately, my brother didn't
have any hand cleaner at his house, but I did find a box of washing soda (Na<sub>2</sub>CO<sub>3</sub> under the kitchen sink. I wet my hands under the tap and scrubbed them with the
coarse powder, then rinsed thoroughly. The base completely removed every trace of primer. The skin felt slippery afterward; if I recall correctly
this is caused by the moderate/strong base disrupting cell membranes.
So, if you're willing to put up with a little pain, sodium carbonate and water will clean many stubborn residues off your hands (and strip off a bit
of epidermis).
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Fantasma4500
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this is because the fat in your hands are converted into glycerine and other things (soap?)
NaOH + animal fat is how you make soap, the glycerine is what makes it so slippery, this can be removed quickly with a acid wash, otherwise it might
take many handrubbings to remove that effect, paper should do the job also, but yes if you have something release from beneath the skin, then it would
make sense to push out whatever stuck to the skin
one thing
dont play around with bases, as you will eventually end up with no fat around your hands (also youre wrists)
you will get very bony hands
plausible a way to loose fat extremely fat, but im a bit worried if this could go deeper in your body and be very hard to wash out, etching your body
apart?
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bfesser
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That sounds erroneous to me. People had been using washing soda for laundry for a long time before modern detergents, and much of that washing was
done by hand. Some people (like my weird brother) still use it, although more often in an automatic machine. I'm not recommending constant exposure
to concentrated sodium carbonate, but an occasional cleaning shouldn't do irreversible damage. Have you been reading too many MSDS? 
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Fantasma4500
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not really
if SO3 fills my room i dont run, i fix it (;
actually demonstrated to my classmate how you can detect highly basic liquids - by taking some on your finger and rubbing
infact for higher order christian believers who wanted to make others think they had a sign from god, they took on a piece of cotton a concentrated
solution of NaOH and made a cross on their arm etc.
an hour later after severe itchyness the skin would have sunken down abit, where the shape of the liquid would appear
this has been done accidentally also, a guy i know who worked at a factory had a tiny droplet of it land on his sock and somehow get in contact with
his skin, he didnt care about the minor itchiness, when he went home he found out he had a small 'hole' or crater in his skin
if any MSDS would be worrying to me, then it would be nicotine, caffeine and dichromates
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Fantasma4500
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various stains, increasingly more and more messy
so i have this 250 mL erlenmeyer flask on my table in the kitchen, its covere with aluminium foil, not completely airtight, but more than enough, or
so i thought
i have gotten some very very VERY interesting perfectly round circles on the table, that is pretty close to completely white, im considering this
could be the bleaching magic of NO or NO2??
the flask contains PbO and PbO2 set to react with HNO3 btw
i was so stupid to after seeing these circles move the flask and let it stand, thereafter seeing circle number 2 move it and set it on my table AGAIN
good job.
decided it wasnt time for sleeping tonight, so i got back up and went to my kitchen to clean up etc.
why not try to remove the stains?
so then i figured out that KMnO4, thereafter added dilute H2SO4 and finally zinc powder (900 mesh) would do a good job on a wooden table
no.
i guess its time for a picture by now
starting point
http://imgur.com/TN6n4GP
NOW.
http://imgur.com/Lv75Qo9
now that i get to think about it, KMnO4 + H2SO4 dilute would give H2MnO4, or HMnO4, which would then go into MnO7 (or doesnt this happen with dilute
H2SO4??)
anyhow seemingly reacting with the wood putting in a pretty annoying amount of MnO2
the stain was much more violent some time ago than it was now when i took the picture
doesnt look good anyhow
i put on some NaHSO3 and ascorbic acid as they have shown to remove MnO2 pretty well, but this looks like a new level of intensity and pretty overall
de-cleaning
if anybody survived a situation alike this please give some advice??
edit: update
seemingly this approach is if kept wet during all times and not leaving it to settle actually useful, tho i still have a faint stain of MnO2 deposited
in the wood
of what i see its no longer bleached so horifically, which is good, but im not entirely sure, perhaps KMnO4 H2SO4 and Zinc is useful for this anyways?
[Edited on 17-7-2013 by Antiswat]
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bfesser
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Threads Merged
18-7-2013 at 16:52 |
bfesser
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Thread Split
18-7-2013 at 16:54 |
zenosx
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Not delving into the chemistry I will just throw out there that the white circle looked a hell of a lot better than the bloody looking stain After
cleaning there Antiswat
Sorry couldn't resist  Have you tried the tried and true NaOCL yet on the stain?
A question that sometimes drives me hazy: am I or are the others crazy?
Albert Einstein
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Zyklon-A
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Sorry if this was already mentioned, I skimmed of the whole thread, but didn't read all of it.
How can I remove a nitric acid stain? I spilled some fuming nitric acid on my fingers, is there a way to get the yellow stain off?
Never mind, I found this http://www.sciencemadness.org/talk/viewthread.php?tid=22590 Still didn't really answer my question...
[Edited on 23-4-2014 by Zyklonb]
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Crowfjord
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If I recall correctly, nitric acid stains skin by nitrating the phenylalanine and tyrosine residues in skin proteins. As such, you pretty much just
have to wait for that portion of skin to die and peel off. Just another mark of a chemist...
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Fantasma4500
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speaking of marks of a chemist: be very very careful with pyrotechnical compositions containing phosphorus..
KMnO4 + red phosphorus behaves SOMEWHAT alike with chlorate/perchlorate, although when i tried it, it shot a gigantic shower of phosphorus, resulting
in very deep burns in my skin
on a sidenote: 70% HNO3 is enough to nitrate skin, or as crowfjord enlightened us with: phenylalanine and torosine
also zenosx: yes i.. i tried everything
styphnic acid however, quite staining aswell..
however its not much of a problem as i had a fire in my appartment and entire kitchen was ripped apart and exchanged with a nice new kitchen which
seems to have a table alot more stain-proof
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Bert
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That kitchen fire was the ULTIMATE STAIN REMOVER! There are days I fantasize about cleaning the floors like that ...
Keep some Copper sulfate solution around for those Phosphorus debridement moments?
There's almost nothing a professional pyrotechnic manufacturer USES red phosphorus for- Pull/scratch igniters are about all I can think of.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Zyklon-A
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Antiswat , Ouch! That's way worse than a little 98% nitric acid. My burns no longer hurt, and the stain is almost gone. My
finger nail is still orange, I doubt that will go away until the entire length of nail grows back.
I still have a deep scar, which doesn't look like it's going anywhere either.
Speaking about Marks of the Chemist!
[Edited on 25-4-2014 by Zyklonb]
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Fantasma4500
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oh yes.. seen that video.. never felt really safe with thin glass in my hand.. even if you try to stop your hand your reflexes must be subliminal to
avoid getting for example a broken glass thermometre shoved through your hand.. you sometimes need to push quite hard to get glass through rubber
stoppers
however the phosphorus burns was just like.. 0.1mm burn hole size, but still very deep.. many times deeper than its width, not to mention the P2O5
would create phosphoric anhydride from the water in your body.. quite the combo
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Texium
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Ok, bit of a problem here. I melted some indium in my ceramic crucible… forgetting that it wets glass. Now I have little bits of indium all stuck to
the bottom of the crucible. Any ideas on how to get it out?
Edit: Never mind. I feel silly for asking now. I just put some HCl in there and that cleaned it up just fine. I guess I thought that indium was less
reactive than it actually is for some reason.
[Edited on 5-10-2014 by zts16]
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hyfalcon
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I have a similar problem on porcelain tile. On a side note, how would one go about removing picric acid stains on counter tops?
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Fantasma4500
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i dont think there are any solution to that, hyfalcon..
same shit with styphnic acid solutions
perhaps just pour it all over the table and get a nicely fluorescent table
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HeYBrO
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Quote: Originally posted by woelen  | | A very good way of removing such brown stains is rinsing with an acidified solution of sodium sulfite or bisulfite. Stained glass becomes clear again
at once. Equally well works a solution of 1% H2O2 in dilute acid. Both solutions reduce the brown MnO2 to colorless Mn(2+), which goes into solution
at once. |
Interestingly, I've found that with MnO2 that has been deposited on to glassware, some 3% H2O2 works actually quite
well for dislodging most of the MnO2. seems its to due with the decomposition and the micro bubbles which are formed.
However, it remains insoluble and it not as efficient as acidified hydrogen peroxide as there is usually a little left which has to be scrubbed.
[Edited on 30-6-2014 by HeYBrO]
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Texium
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Really Nasty Old Glassware
I've been fortunate enough to have recently obtained a very large amount of nice assorted glassware, practically tripling my amount lab equipment
(which was not very much before this). The downside is that it was stored in an old non-climate-controlled shipping container for around 8 years, so
it has all manners of filth on it, plus some pieces that still have residue remaining from the previous owner.
I was thinking of cleaning it with sodium hydroxide and then sulfuric acid, but I wasn't sure exactly what concentrations of each I should use, or if
I should use different chemicals entirely to get the job done.
The possible stuff on the glassware includes generic dust, rodent poop, dead insects/scorpions/small animals, bits of paper and cardboard, grease, and
some unidentified organic compound residues on some of the pieces.
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gdflp
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Hexavalent chromium and concentrated sulfuric will most likely attack everything but for that much glassware it's expensive and dangerous. I would
try a saturated solution of an alkali hydroxide in 95% ethanol or isopropanol. Dont leave it in too long though(check on it once every few hours to
see how it's progressing), or soak ground glass joints as it will slowly dissolve the glass and may effect the fit of the joint. If it's still not
clean, try a soak in some concentrated hydrochloric or sulfuric acid. Acetone tends to be a good solvent for many stubborn organics.
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Texium
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Alright, great, thanks for the input! I'll take all of that into consideration when I start working on it.
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Ascaridole
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Ha so that's where your cool unknowns are coming from... 6M nitric is good for organics and inorganic crap. That's what I use at work and home to keep
my analytical glass in good shape. Chromic acid also suffers from adding chromium contaminants to your glass, not always a problem but in analytical
chem not fun. Also synthetic glass soaked in a base bath should be cautiously used with high vac. One or two tratments won't ruin it but repeated base
baths will etch the surface enough to make it and implosion hazzard. This is of significant concern with used glass as you never know if the previous
owner base bathed them.
Ascaridole, the masked bandit of chemistry!
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Texium
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Yeah, I have more unknowns to post on that thread once I unpack them, probably tomorrow. I started cleaning the stuff today, and just went with sodium
hydroxide for most stuff, and sulfuric acid when that didn't work.
Normally when I clean my glassware I won't use sodium hydroxide, so I don't think it would be anything to worry about, especially because this stuff
is all from the 1950s at the latest, and it's really heavy duty. The filtering flasks are practically twice as thick as they make them nowadays.
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Texium
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Cleaning carbon from Büchner funnel
Well, I feel like I made one of those silly mistakes that inexperienced people make when they have fancy equipment to play with.
I was filtering the suspended carbon out of an iron sulfate solution using a Büchner funnel and very sensitive filter paper, but the paper didn't fit
exactly right and now I have little particles of carbon stuch in the ceramic part of the funnel. I tried reacting it with conc. sulfuric acid, but
that didn't seem to work very well. Any suggestions are much appreciated, thanks.
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Oscilllator
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| Quote: Originally posted by zts16 | Well, I feel like I made one of those silly mistakes that inexperienced people make when they have fancy equipment to play with.
I was filtering the suspended carbon out of an iron sulfate solution using a Büchner funnel and very sensitive filter paper, but the paper didn't fit
exactly right and now I have little particles of carbon stuch in the ceramic part of the funnel. I tried reacting it with conc. sulfuric acid, but
that didn't seem to work very well. Any suggestions are much appreciated, thanks. |
The best advice I have is just to deal with it. Carbon will not react with just about anything you are ever going to put down that funnel, so the only
issue you are going to have is a cosmetic one. I have heard that chromic acid will clean Carbon stains, but I have been unable to verify that for
myself and besides, dichromates are hard to get and toxic. I personally have a number of flasks that have small flecks of carbon stuck on them.
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gdflp
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I always hear this, but I can never figure out why. Are they difficult to source in Europe? I live in the US and I know of four sources where you
can easily and cheaply buy a pound of dichromate.
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Zyklon-A
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I sold him 100 grams of potassium dichromate, a few months ago, so he probably still has some.
What about nitric acid, wouldn't that get rid of carbon?
[EDIT] gdflp, How cheap for you'r dichromate source?
I bought a pound for nearly $30.00 (including shipping) and wouldn't really call that 'cheap'.
[Edited on 29-7-2014 by Zyklon-A]
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