9 Jan
2006
9 Jan
'06
5:22 a.m.
On Jan 6 2006, 16:20, Bj??rn Vermo wrote:
some
Some of you seem to have slightly odd ideas about detergents :-)
I know of no dishwasher detergent that contains chlorine (which is a
gas) nor large amounts of chlorine-based bleaches. (Mild) Bleaches and
brightners are common in *clothes* detergents where there are good for
stain removal, but they're *not* good in dishwashers, where the bleach
would tend to fade patterns on crockery. Therefore dishwasher
detergent manufacturers use only very small amounts, if any, and
they're usually oxygen-based.
More to the point though, they don't contain silicon dioxide, at least
not any I've come across (btw it's silicon, not silicone). They might
feel gritty, but that's not sand, it's solid detergent. If you
dissolve dishwasher detergent (loose powder or a tablet) in a jug of
water, it will eventually dissolve completely, leaving no sand behind.
Do you think manufacturers would put sand, one of the few common
substances that will scour glass, into a substance used for cleaning
glassware?
If you're worried about the powder, it's perfectly possible to get
liquid dishwater detergent.
Crystal soda is not a detergent. It's sodium carbonate, Na2CO3. It
*is* caustic, it's a mild alkali. That's why it works -- it saponifies
oils, in the same way caustic soda or caustic potash do. That is to
say, it chemically reacts with oil and similar things to turn them into
something water-miscible. Detergent, on the other hand, does not react
with oils, it works like soap to mix with free oily substances and
water. Ammonia is worse and not good for some plasics. Don't put
those in your dishwasher.
Finally, detergent won't damage copper, aluminium, steel, or other
metal. Water will. Detergents can remove oils and other thin-film
coating that might protect metal, so it is wise to dry things carefully
after getting them wet because water and air can cause corrosion, but
it's not the detergent that does that, it's the water. Well, actually
it's the air, but water permits various electrolytic reactions that
hasten the process.
--
Pete Peter Turnbull
Network Manager
University of York
On Fri, 06 Jan 2006 15:26:13 +0100, James Fogg
<James at jdfogg.com>
wrote:
All automatic dishwasher detergents have lots of chlorine and might
bleach (great for discolored plastics),
Not just that, it might cause highly unwanted chemical reactions with plastics, and certainly with any exposed copper.
> Powdered automatic dish detergent has silicone dioxide (sand) and
will
> scour your boards,
>
> Because of the above 2 items you might want to use "hand"
dishwashing
detergent, but
not much since it will foam,
I would suggest crystal soda, it is a good detergent and not overly
caustic, and the rinsing cycle will get rid of residues.
Ammonia solution would work, but would be quite smelly. 
9 Jan
9 Jan
12:32 p.m.
Do you think manufacturers would put sand, one of the
few common
substances that will scour glass, into a substance used for cleaning
glassware?
Sand, no, but silicon dioxide, quite possibly. (Not all silicon
dioxide is sand.) In sufficiently fine particles, it won't hurt
anything - consider that polishing agents are basically just abrasives
on a very fine scale.
Detergent, on the other hand, does not react with
oils, it works like
soap to mix with free oily substances and water.
I've heard that that's not actually true, that detergents actually
cleave fats and oils, digesting them, if you will - that that's the
difference between detergents and soaps, in fact. But that was afrom a
relatively non-authoritative source; anyone here actually know the
chemistry of detergents and how they differ from soaps?
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12:33 p.m.
Pete Turnbull wrote:
Do you think manufacturers would put sand, one of the
few common
substances that will scour glass, into a substance used for cleaning
glassware?
What is it that etches glass in a dishwasher?
Finally, detergent won't damage copper, aluminium,
steel, or other
metal. Water will. Detergents can remove oils and other thin-film
coating that might protect metal, so it is wise to dry things carefully
after getting them wet because water and air can cause corrosion, but
it's not the detergent that does that, it's the water. Well, actually
it's the air, but water permits various electrolytic reactions that
hasten the process.
I don't have any problems with corrosion when cleaning metal with
dishsoap. However, if I use dishwasher soap in a dishwasher on metal,
I'll get corrosion every time. I'm stripping oil off both ways.
Chad Fernandez
Michigan, USA
2:16 p.m.
Do you think
manufacturers would put sand, one of the few common
substances that will scour glass, into a substance used for cleaning
glassware?
What is it that etches glass in a dishwasher? I don't have any problems with corrosion when
cleaning metal with
dishsoap. However, if I use dishwasher soap in a dishwasher on metal,
I'll get corrosion every time. I'm stripping oil off both ways.
Certainly, but you're also putting a fairly caustic solution on it to
help it along, at least for some metals. I have brass fittings on hose
assemblies that turn black during cleaning with detergent (which I now
avoid). And beware of aluminum trim on things, which will lose their
shine. Copper doesn't seem very reactive though--a Good Thing, since
you home's pipes are likely copper, but I'm not entirely sure, since
those pipes also carry a lot of water otherwise to dilute the solution.
I don't know of any dish soaps that contain lye (but we've used one
brand for years). I think it would be too hard on your hands (or those
of she who must be obeyed) to be a popular product.
Patrick
10 Jan
10 Jan
7:09 a.m.
----- Original Message -----
From: Pete Turnbull <pete at dunnington.plus.com>
Date: Monday, January 9, 2006 10:22 am
Subject: Re: cleaning keyboards in the dishwasher
Some of you seem to have slightly odd ideas about detergents :-)
I know of no dishwasher detergent that contains chlorine (which is a
gas) nor large amounts of chlorine-based bleaches. (Mild)
Bleaches and
brightners are common in *clothes* detergents where there are good for
stain removal, but they're *not* good in dishwashers, where the bleach
would tend to fade patterns on crockery. Therefore dishwasher
detergent manufacturers use only very small amounts, if any, and
they're usually oxygen-based.
More to the point though, they don't contain silicon dioxide, at least
not any I've come across (btw it's silicon, not silicone). They might
feel gritty, but that's not sand, it's solid detergent. Ok To start with
I'm no expert. Having said that I feel free to
pontificate!
Dish washer detergents have changed considerably over the past fifteen
years in response to concerns about the eutrification of waterways as a
results of detergent contamination. This has resulted in a very
dramatic drop in the phosphate content.
A dishwasher detergent has to shape up or "polish" the incoming water
supply and combine with and remove the grease etc present. To this end
they may contain silicon dioxide in the form of cage compounds which
capture metals etc out of the incoming water and prevent a metallic
stain building up on dishes as the water is dried on them repeatedly
over a period of time. To detect the presence of these try and repeat
your experiment of dissolving dishwasher detergent completely, its a
lot harder now than it used to be. As you so rightly state chlorine
based bleaches are rare in dishwasher detergent, however high
temperature based Oxygen bleaches are becoming more common to break up
grease etc. To test for these add close to boiling water to dishwasher
detergent and you will normally find that a large amount of gas is
released.
Finally the very dramatic corrosion that can occur with aluminium
appears to be electrolytic in nature and is generally strongly promoted
when the aluminium is in contact with another metal such as stainless
steel cutlery. This is the basis of one method used to polish silver,
where you line a vessel with tinfoil (aluminium) and place the
silverware in there with plenty of hot water and a little detergent or
preferably washing soda.
My 2c.
All the best
Laurence Cuffe
> Because
of the above 2 items you might want to use "hand"
dishwashing
detergent, but not much since it will foam,
I would suggest crystal soda, it is a good detergent and not overly
caustic, and the rinsing cycle will get rid of residues.
Ammonia solution would work, but would be quite smelly. Finally, detergent won't damage copper, aluminium,
steel, or other
metal. Water will. Detergents can remove oils and other thin-film
coating that might protect metal, so it is wise to dry things
carefullyafter getting them wet because water and air can cause
corrosion, but
it's not the detergent that does that, it's the water. Well, actually
it's the air, but water permits various electrolytic reactions that
hasten the process.
--
Pete Peter Turnbull
Network Manager
University of York
1:07 p.m.
On 1/10/2006 at 12:09 PM Laurence Cuffe wrote:
Dish washer detergents have changed considerably over
the past fifteen
years in response to concerns about the eutrification of waterways as a
results of detergent contamination. This has resulted in a very
dramatic drop in the phosphate content.
To be sure, phosphate is no longer a primary content, but a quick perusal
of MSDS for some common brands used in the USA discloses that sodium
carbonate or sodium perborate (borax) seems to be used as a
substitute--along with the legal limit of phosphate. The chemistry is
basically the same--sodium carbonate hydrolysis in the presence of very hot
water results in a very basic solution. Said solution will attack
aluminum, zinc and magnesium quite readily--as well as saponify grease.
I would believe that basic chemistry would have changed if detergents used
in automatic dishwashers no longer required very hot water, but that
doesn't seem to be the case. At least I'm aware of no dishwasher detergent
that allows use of cold water.
If you're in doubt about any preparation, it's always a good idea to
consult the MSDS. Manufacturers are required to make it available to the
public by law. Quite often, you'll be surprised at what you find.
Cheers,
Chuck
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days inactive
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5 comments
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participants (6)
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cclist＠sydex.com -
fernande＠internet1.net -
Laurence.Cuffe＠ucd.ie -
mouse＠Rodents.Montreal.QC.CA -
patrick＠vintagecomputermarketplace.com -
pete＠dunnington.plus.com