Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of thickness
can you cut? What kind of volume of water does it move?

Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of thickness
can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Jon

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of
thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Yeah, that's the kind of pressure I am seeing too. Looks like there is no
poor man's DIY setup for that either.

Bob La Londe wrote:

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of
thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Yeah, that's the kind of pressure I am seeing too. Looks like there is no
poor man's DIY setup for that either.

You can use a normal pressure washer pump (1,500-5,000 PSI) to make a
poor man's non abrasive water jet cutter... just like they use for
cutting cakes and similar in some bakery facilities. I'm not sure how
much use there is for a home CNC water jet cake cutter however.

"Bob La Londe" wrote in message
...
"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures does it take? How is the nozzle shaped internally? What kind
of thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Yeah, that's the kind of pressure I am seeing too. Looks like there is no
poor man's DIY setup for that either.

I have worked around a number of water jet machines, for both cutting and
blasting, nothing about them are cheap in any way. Maintenance on those 50k
PSI pumps can be brutal and filtration of the waste water expensive. IIRC,
our machines had to use deionized water.

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of
thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that the
early experiments, and some of the early commercial units, could do some
amazing cutting with water alone. In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah Lee
chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal now
use abrasive grit. Still, the ability to cut with plain water is a read
head-shaker, IMO.

--
Ed Huntress

"Pete C." wrote in message
ster.com...

Bob La Londe wrote:

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures
does it take? How is the nozzle shaped internally? What kind of
thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Yeah, that's the kind of pressure I am seeing too. Looks like there is
no
poor man's DIY setup for that either.

You can use a normal pressure washer pump (1,500-5,000 PSI) to make a
poor man's non abrasive water jet cutter... just like they use for
cutting cakes and similar in some bakery facilities. I'm not sure how
much use there is for a home CNC water jet cake cutter however.

It looks like more effort than it would be worth. I covered non-traditional
machining for _American Machinist_ a few decades ago and I remember the cake
slicers that would also cut metal. Amazing.

--
Ed Huntress

"Ed Huntress" wrote in message
...

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures does it take? How is the nozzle shaped internally? What kind
of thickness can you cut? What kind of volume of water does it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that the
early experiments, and some of the early commercial units, could do some
amazing cutting with water alone. In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah
Lee chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal
now use abrasive grit. Still, the ability to cut with plain water is a
read head-shaker, IMO.

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to expensive
to have done. Granite is cheap. Cut granite is very expensive. I was
hoping to be able to make cuts up to 3-4 feet thick. Looks like I either
need a $50K machine or to spend the rest of my life on one project. Neither
is palatable so this idea will have to pass for now.

On Aug 28, 10:33*am, "Ed Huntress" wrote:
"Jon Elson" wrote in message

...

Bob La Londe wrote:
Anybody here play with this kind of cutter? *What kind of water pressures
does it take? *How is the nozzle shaped internally? *What kind of
thickness can you cut? *What kind of volume of water does it move?

Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. *The water is loaded with garnet grit to do the actual
cutting. *I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. *It took maybe 2
minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that the
early experiments, and some of the early commercial units, could do some
amazing cutting with water alone. In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah Lee
chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal now
use abrasive grit. Still, the ability to cut with plain water is a read
head-shaker, IMO.

--
Ed Huntress

Several years ago I was doing some research for investment purposes
into a company that was using high pressure LIQUID Nitrogen for jet
cutting. Electronic circuit boards and meat cutting were some of the
uses they were investigating at that time. I filled up my flash drive
where I was storing all that information and put it away. I probably
should dig through it again and see what kind of progress they have
made.

I think it was the University of Nevada Las Vegas that was leading the
research into this along with one of the Idaho Universities. The Idaho
team was experimenting with it for cutting metals IIRC.

I can think of some interesting possibilites.
DL

"Bob La Londe" wrote in message
...
"Ed Huntress" wrote in message
...

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures does it take? How is the nozzle shaped internally? What
kind of thickness can you cut? What kind of volume of water does it
move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the actual
cutting. I watched a demo of cutting 1/2" diameter holes through a 4"
block of Inconel, which was really quite impressive. It took maybe 2
minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that the
early experiments, and some of the early commercial units, could do some
amazing cutting with water alone. In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah
Lee chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal
now use abrasive grit. Still, the ability to cut with plain water is a
read head-shaker, IMO.

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to expensive
to have done. Granite is cheap. Cut granite is very expensive. I was
hoping to be able to make cuts up to 3-4 feet thick. Looks like I either
need a $50K machine or to spend the rest of my life on one project.
Neither is palatable so this idea will have to pass for now.

(rough cuts would have been satisfactory. This is not for a counter top or
something like that. Think bigger. A lot bigger.)

Bob La Londe wrote:
"Ed Huntress" wrote in message
...

"Jon Elson" wrote in message
...
Bob La Londe wrote:
Anybody here play with this kind of cutter? What kind of water
pressures does it take? How is the nozzle shaped internally? What
kind of thickness can you cut? What kind of volume of water does
it move?



Typical units use about 40,000 to 50,000 PSI, and maybe half a
gallon/minute. The water is loaded with garnet grit to do the
actual cutting. I watched a demo of cutting 1/2" diameter holes
through a 4" block of Inconel, which was really quite impressive.
It took maybe 2 minutes for each hole.

Jon

Today's commercial WJCs use garnet, but it's interesting to note that
the early experiments, and some of the early commercial units, could
do some amazing cutting with water alone. In fact, I remember one
company that I reported on that sold the same model to a company that
was slicing Sarah Lee chocolate cakes and, in the building next door,
to one that cut cement-reinforced slag-fiber ("rock wool") insulation
panels.

You can cut steel with plain water, but it's very slow. I haven't
kept up but I think that all of the commercial units designed for
cutting metal now use abrasive grit. Still, the ability to cut with
plain water is a read head-shaker, IMO.

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to
expensive to have done. Granite is cheap. Cut granite is very
expensive. I was hoping to be able to make cuts up to 3-4 feet
thick. Looks like I either need a $50K machine or to spend the rest
of my life on one project. Neither is palatable so this idea will
have to pass for now.
Can you not use a wire saw something like used commercially. IIRC the
old ones, before diamond coated blades, used a soft metal wire, like
copper, and grit was fed into the cut and embedded into the soft blade
like a lap to cut the harder material. The blade is often a continuous
loop like a bandsaw. A program I saw showed that the Egyptians used the
process but the saw was a hand powered reciprocating saw.

"Bob La Londe" writes:

Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of thickness
can you cut? What kind of volume of water does it move?

I knew of one used to cut a building apart, piece by piece. Slab,
pillar, I-beam, rebar, pipe.... no problem.

I'm not aware they used any grit, just lots of water.







--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Bob La Londe" wrote in message
...
"Ed Huntress" wrote in message
...


I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to expensive
to have done. Granite is cheap. Cut granite is very expensive. I was
hoping to be able to make cuts up to 3-4 feet thick. Looks like I either
need a $50K machine or to spend the rest of my life on one project.
Neither is palatable so this idea will have to pass for now.

to cut stone all you need is steel wire, some pulleys, something to move it,
and some grit - take your time

Bob La Londe wrote:

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to
expensive to have done. Granite is cheap. Cut granite is very
expensive. I was hoping to be able to make cuts up to 3-4 feet thick.
Looks like I either need a $50K machine or to spend the rest of my life
on one project. Neither is palatable so this idea will have to pass for
now.

You can drill a starter hole with a diamond core drill, although 3-4
FEET is going to be slow going. Once through, you can use aircraft
cable (braid) with oil or water and diamond grit to saw it. I think
that's what the pros use.

Jon

"Bob La Londe" wrote:

Anybody here play with this kind of cutter? What kind of water pressures
does it take? How is the nozzle shaped internally? What kind of thickness
can you cut? What kind of volume of water does it move?


I worked with non abrasive waterjet for a number of years, uses the same type of
intensifier and those things are very expensive. My stuff operated at the 50-55,000 psi
range.

I was using diamond or saphire (cheap) nozzles with a 0.005" - 0.007" orifice.

Plumbing uses special connectors where the pipe is threaded for a left hand ferrule that
is compressed by a right hand nut, the end is coned at ~45 degrees and the connectors have
a mating cone about a degree different to cause cause an interferance fit. Plumbing tends
to be 304 or 316 depending.

http://www.autoclave.com/ To see fittings.

http://www.highpressure.com/valves_index.asp?ID=3 They were less expensive than Autoclave
back in the late 90's.

Intensifier piston rod is solid carbide on an Ingersol streamline and check valves have a
short life. The best swivel is a coil of tubing. They make swivels but they tend to go
for a grand+ or so and eventually fail.

Oh, there is no such thing as a minor leak in a waterjet system. The biggest issue I had
with production is they liked to keep running when ever a leak started, that water cuts
everything, you got to be on top of repairs or it will cost you even more.

Most of my comments apply to abrasive jet, that has a system to introduce garnet iirc into
the water after it exits the orifice.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Ed Huntress" wrote:

It looks like more effort than it would be worth. I covered non-traditional
machining for _American Machinist_ a few decades ago and I remember the cake
slicers that would also cut metal. Amazing.

I know Sara Lee uses waterjet to cut some of their offerings.

Wes

"Ed Huntress" wrote:

In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah Lee
chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

Should have read all the thread before I responded to your earlier post. Was the company
Ingersol-Rand?

You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal now
use abrasive grit. Still, the ability to cut with plain water is a read
head-shaker, IMO.

Well there is that Grand Canyon

Seriously, One of the apps I had was profiling low density fiberglass headliner shells.
The waterjet nexts needed periodic repair (welding), cut the same outline 50,000 times,
you will cut though the deflectors in places.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Tim" wrote:

IIRC,
our machines had to use deionized water.

I heard a horror story where a facility put in a reverse osmosis system to take all
impurites out of the feed water. Then they started having even more problems. Really
pure water attacks the alloying elements in the plumbing.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

"Wes" wrote in message
...
"Ed Huntress" wrote:

In fact, I remember one company that I
reported on that sold the same model to a company that was slicing Sarah
Lee
chocolate cakes and, in the building next door, to one that cut
cement-reinforced slag-fiber ("rock wool") insulation panels.

Should have read all the thread before I responded to your earlier post.
Was the company
Ingersol-Rand?

It may have been; that sounds familiar. But it was too long ago for me to
remember.


You can cut steel with plain water, but it's very slow. I haven't kept up
but I think that all of the commercial units designed for cutting metal
now
use abrasive grit. Still, the ability to cut with plain water is a read
head-shaker, IMO.

Well there is that Grand Canyon

Seriously, One of the apps I had was profiling low density fiberglass
headliner shells.
The waterjet nexts needed periodic repair (welding), cut the same outline
50,000 times,
you will cut though the deflectors in places.

Wes

I'm not sure I followed that last paragraph. 'You want to read it again and
see if it's you or it's me?

--
Ed Huntress

"Wes" wrote in message
...
"Tim" wrote:

IIRC,
our machines had to use deionized water.

I heard a horror story where a facility put in a reverse osmosis system to
take all
impurites out of the feed water. Then they started having even more
problems. Really
pure water attacks the alloying elements in the plumbing.

It may have been taking out the iimpurities, or it may have been a pH effect
from the process. Some kinds of "distilled" water are slightly acid.

So is rainwater. I understand that the latter is the result of picking up
carbon dioxide from the atmosphere on the way down, and forming a very weak
solution of carbonic acid. But I got that second-hand.

--
Ed Huntress

"Ed Huntress" wrote:

I'm not sure I followed that last paragraph. 'You want to read it again and
see if it's you or it's me?

nexts = nests. My bad on spelling. The nest fit the show side of headliner and used
vacuum to hold the part to it, the cut lines had SS blast deflectors to protect the rest
of the nest.

The portions of the profile that I had to dwell on to get a sharp corner tended to have
their blast deflectors wear though soonest. At first we made new ones, later we just
welded them up, quicker and easier.

Wes

"Wes" wrote in message
...
"Ed Huntress" wrote:

I'm not sure I followed that last paragraph. 'You want to read it again
and
see if it's you or it's me?

nexts = nests. My bad on spelling. The nest fit the show side of
headliner and used
vacuum to hold the part to it, the cut lines had SS blast deflectors to
protect the rest
of the nest.

The portions of the profile that I had to dwell on to get a sharp corner
tended to have
their blast deflectors wear though soonest. At first we made new ones,
later we just
welded them up, quicker and easier.

Wes

Waterjet seems to have a lot of tricky, unanticipated issues. The early ones
were hellishly loud, and you had to wear hearing protection when you were in
the same room. Is that still true?

--
Ed Huntress

"Ed Huntress" wrote:

Waterjet seems to have a lot of tricky, unanticipated issues. The early ones
were hellishly loud, and you had to wear hearing protection when you were in
the same room. Is that still true?

On what we cut, low density fiberglass headliner shells it wasn't too bad. Positioning
the nozzle as close to the cut helped keep noise down.

Now on a prototype corvette seat back we were developing for Lear out of many layers of
woven glass impregnated via the SRIM process, we upped the orifice to about 0.010" and
that was damn loud. Non abrasive WJ wasn't the tool for this, too slow. Anyway, Lear
took that back in house and we ended up wasting too much time and resources on that one.

Wes

I find the pure water - attacks ? I don't think so.

Chlorine and such will. H2O is stable. If they have
electric current flowing in the pipes - possible - it can
break down H2O into hydrogen gas and oxygen gas.
The hydrogen will attack steel. The oxygen will attack
almost anything.

I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

Martin

Wes wrote:
"Tim" wrote:

IIRC,
our machines had to use deionized water.

I heard a horror story where a facility put in a reverse osmosis system to take all
impurites out of the feed water. Then they started having even more problems. Really
pure water attacks the alloying elements in the plumbing.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Ed Huntress wrote:
"Wes" wrote in message
...
"Ed Huntress" wrote:

I'm not sure I followed that last paragraph. 'You want to read it again
and
see if it's you or it's me?
nexts = nests. My bad on spelling. The nest fit the show side of
headliner and used
vacuum to hold the part to it, the cut lines had SS blast deflectors to
protect the rest
of the nest.

The portions of the profile that I had to dwell on to get a sharp corner
tended to have
their blast deflectors wear though soonest. At first we made new ones,
later we just
welded them up, quicker and easier.

Wes

Waterjet seems to have a lot of tricky, unanticipated issues. The early ones
were hellishly loud, and you had to wear hearing protection when you were in
the same room. Is that still true?


I watched a demonstration of an abrasive waterjet system cutting 1/8"
aluminum and the pump made some noise, but the cutting was under water
and did not make noise that I remember. The whole workpiece was under a
few inches of water that got pumped in before the cutting started and
pumped out to below the workpiece when done.

BobH

"BobH" wrote in message
.. .
Ed Huntress wrote:
"Wes" wrote in message
...
"Ed Huntress" wrote:

I'm not sure I followed that last paragraph. 'You want to read it again
and
see if it's you or it's me?
nexts = nests. My bad on spelling. The nest fit the show side of
headliner and used
vacuum to hold the part to it, the cut lines had SS blast deflectors to
protect the rest
of the nest.

The portions of the profile that I had to dwell on to get a sharp corner
tended to have
their blast deflectors wear though soonest. At first we made new ones,
later we just
welded them up, quicker and easier.

Wes

Waterjet seems to have a lot of tricky, unanticipated issues. The early
ones were hellishly loud, and you had to wear hearing protection when you
were in the same room. Is that still true?


I watched a demonstration of an abrasive waterjet system cutting 1/8"
aluminum and the pump made some noise, but the cutting was under water and
did not make noise that I remember. The whole workpiece was under a few
inches of water that got pumped in before the cutting started and pumped
out to below the workpiece when done.

BobH

That's interesting. I don't remember many details about the waterjets I saw
a few decades ago; they were still a curiosity and I didn't spend a lot of
time with them. I do remember the noise, however. It was fierce when they
were cutting metal. Maybe the underwater cutting came later?

--
Ed Huntress

"
I watched a demonstration of an abrasive waterjet system cutting 1/8"
aluminum and the pump made some noise, but the cutting was under water and
did not make noise that I remember. The whole workpiece was under a few
inches of water that got pumped in before the cutting started and pumped
out to below the workpiece when done.

BobH

the unit's demonstrated at Westech are cutting about 1 inch AL, not too
noisy, the jet is about 1/4 inch above the AL - I don't think I'd want my
ear next to the jet, but it's certainly quieter than a lot of other cutting
tools

On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:

I find the pure water - attacks ? I don't think so.

Chlorine and such will. H2O is stable. If they have
electric current flowing in the pipes - possible - it can
break down H2O into hydrogen gas and oxygen gas.
The hydrogen will attack steel. The oxygen will attack
almost anything.

I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

Martin

We had to guard against using de-ionized water in recirculating
cooling systems for extruders (primarily D2 steel). The operations
manual from the manufacturer warned against it due to excessive
corrosion. Specs were given for water quality.

Of course, this was in boiling service. Cooling was accomplished by
small shots of water into the cooling channels in the extruder
barrels, which since they were at 2-300 deg C caused the water to
immediately flash to steam.

Pete Keillor

Wes wrote:
"Tim" wrote:

IIRC,
our machines had to use deionized water.

I heard a horror story where a facility put in a reverse osmosis system to take all
impurites out of the feed water. Then they started having even more problems. Really
pure water attacks the alloying elements in the plumbing.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:

I find the pure water - attacks ? I don't think so.

DI water attacks copper and copper based alloys quite aggressively.
Austenitic stainless steels and nickel base alloys are generally OK,
though I have experience with Inconel immersion heaters corroding
surprisingly fast, even at relatively low temps (140F) in DI water.


Chlorine and such will. H2O is stable. If they have
electric current flowing in the pipes - possible - it can
break down H2O into hydrogen gas and oxygen gas.
The hydrogen will attack steel. The oxygen will attack
almost anything.

I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

The absence of ions would rule out galvanic corrosion, no?


Martin

Wes wrote:
"Tim" wrote:

IIRC,
our machines had to use deionized water.

I heard a horror story where a facility put in a reverse osmosis system to take all
impurites out of the feed water. Then they started having even more problems. Really
pure water attacks the alloying elements in the plumbing.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

--
Ned Simmons

Steam power plants - all of them run by steam generated.
They must use what they call is "holy water". It is as pure
as possible as they run very hot pressurized steam. The pipes
would clog up if anything was there. Power plants don't
blow up in the steam lines due to hydrogen issues weakening
the steel. I suspect there was a process or two metal issue.
Any two metals leak current. Some are really bad.

Martin

Pete Keillor wrote:
On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:

I find the pure water - attacks ? I don't think so.

Chlorine and such will. H2O is stable. If they have
electric current flowing in the pipes - possible - it can
break down H2O into hydrogen gas and oxygen gas.
The hydrogen will attack steel. The oxygen will attack
almost anything.

I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

Martin

We had to guard against using de-ionized water in recirculating
cooling systems for extruders (primarily D2 steel). The operations
manual from the manufacturer warned against it due to excessive
corrosion. Specs were given for water quality.

Of course, this was in boiling service. Cooling was accomplished by
small shots of water into the cooling channels in the extruder
barrels, which since they were at 2-300 deg C caused the water to
immediately flash to steam.

Pete Keillor

Wes wrote:
"Tim" wrote:

IIRC,
our machines had to use deionized water.
I heard a horror story where a facility put in a reverse osmosis system to take all
impurites out of the feed water. Then they started having even more problems. Really
pure water attacks the alloying elements in the plumbing.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

In article ,
Ned Simmons wrote:

On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:

I find the pure water - attacks ? I don't think so.

DI water attacks copper and copper based alloys quite aggressively.
Austenitic stainless steels and nickel base alloys are generally OK,
though I have experience with Inconel immersion heaters corroding
surprisingly fast, even at relatively low temps (140F) in DI water.


Chlorine and such will. H2O is stable. If they have
electric current flowing in the pipes - possible - it can
break down H2O into hydrogen gas and oxygen gas.
The hydrogen will attack steel. The oxygen will attack
almost anything.

I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

The absence of ions would rule out galvanic corrosion, no?

I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.

Does distilled water attack copper et al? I would think not, because
copper stands up to rainwater pretty well.

Joe Gwinn

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever anions
were originally present, like Cl- or whatever, then a cation exchange resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual 10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in freshman chem
lab all our titrations came out wacky and it turned out the "neutral" DI
water we were using to dissolve our standards was really pH 2 :-). Oh, it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering capacity
any little contaminant can shift the pH substantially. Any that has been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

-----
Regards,
Carl Ijames

In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever anions
were originally present, like Cl- or whatever, then a cation exchange resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual 10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in freshman chem
lab all our titrations came out wacky and it turned out the "neutral" DI
water we were using to dissolve our standards was really pH 2 :-). Oh, it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering capacity
any little contaminant can shift the pH substantially. Any that has been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

I always wondered just how this was supposed to work. Thanks.

I sounds like in a home system it may be difficult to achieve and
maintain neutral pH, as one or the other bed will always be a bit ahead.

Joe Gwinn

On Sun, 30 Aug 2009 09:48:33 -0400, Joseph Gwinn
wrote:

In article ,
Ned Simmons wrote:

On Fri, 28 Aug 2009 22:08:51 -0500, "Martin H. Eastburn"
wrote:


I bet they had a mixed iron and copper system and did themselves
in without using current breaks - plastic joints.

The absence of ions would rule out galvanic corrosion, no?

I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.


The exchanged ions are hydrogen ions and hydroxyl ions.
H + OH - H2O

Does distilled water attack copper et al? I would think not, because
copper stands up to rainwater pretty well.

Rainwater is a long way from distilled water, at least here in the
Northeast. I can't speak to whether distilled water and DI water
affect copper differently. I wouldn't think so, but my experience is
limited to choosing materials compatible with DI water for industrial
processes.

--
Ned Simmons

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever
anions
were originally present, like Cl- or whatever, then a cation exchange
resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual
10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in freshman
chem
lab all our titrations came out wacky and it turned out the "neutral" DI
water we were using to dissolve our standards was really pH 2 :-). Oh,
it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering capacity
any little contaminant can shift the pH substantially. Any that has been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

I always wondered just how this was supposed to work. Thanks.

I sounds like in a home system it may be difficult to achieve and
maintain neutral pH, as one or the other bed will always be a bit ahead.

Joe Gwinn

If you wanted exactly neutral very pure water, yes it would be slightly
tricky. In practice you don't care about exactly neutral pH so it is easy -
each resin takes out whatever is there of each charge and all that is left
is water. Yes, a tiny amount of acid or base can shift the pH, but you
don't care precisely because the buffer capacity is so low - any tiny amount
of anion or cation you add on purpose will be enough to completely swamp out
any slight initial acidity or alkalinity. It's only when you run it through
one resin and not the other (or one resin is saturated and the other one
isn't) that you have a problem. Say you start with salt water and all the
Na+ is exchanged for H+ but the Cl- isn't exchanged for OH-: you just made
HCl, hydrochloric acid :-).

-----
Regards,
Carl Ijames

In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because the
beads used to fill the water treatment gadget are called ion *exchange*
beads or media. The implication is that they have traded one kind of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever
anions
were originally present, like Cl- or whatever, then a cation exchange
resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual
10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in freshman
chem
lab all our titrations came out wacky and it turned out the "neutral" DI
water we were using to dissolve our standards was really pH 2 :-). Oh,
it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering capacity
any little contaminant can shift the pH substantially. Any that has been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

I always wondered just how this was supposed to work. Thanks.

I sounds like in a home system it may be difficult to achieve and
maintain neutral pH, as one or the other bed will always be a bit ahead.

Joe Gwinn

If you wanted exactly neutral very pure water, yes it would be slightly
tricky. In practice you don't care about exactly neutral pH so it is easy -
each resin takes out whatever is there of each charge and all that is left
is water. Yes, a tiny amount of acid or base can shift the pH, but you
don't care precisely because the buffer capacity is so low - any tiny amount
of anion or cation you add on purpose will be enough to completely swamp out
any slight initial acidity or alkalinity. It's only when you run it through
one resin and not the other (or one resin is saturated and the other one
isn't) that you have a problem. Say you start with salt water and all the
Na+ is exchanged for H+ but the Cl- isn't exchanged for OH-: you just made
HCl, hydrochloric acid :-).

Ahh. I was worrying about corrosion of for instance copper, and if I
understand the implications of the above, for instance a bit of salt in
the feedwater will cause the deionizer to produce hydrochloric acid,
which will dissolve the copper in no time. People are far more tolerant
of dilute HCl than copper and stainless steel, so what's good enough for
drinking may not be good enough for a boiler et al. I'm sure that there
are better deionizers, but still...

Joe Gwinn

On Fri, 28 Aug 2009 10:04:10 -0700, "Bob La Londe"
wrote:

"Bob La Londe" wrote in message
...

I was actually thinking of stone. Specifically granite, for a non
traditional idea, but it looks impractical to DIY and its way to expensive
to have done. Granite is cheap. Cut granite is very expensive. I was
hoping to be able to make cuts up to 3-4 feet thick. Looks like I either
need a $50K machine or to spend the rest of my life on one project.
Neither is palatable so this idea will have to pass for now.

(rough cuts would have been satisfactory. This is not for a counter top or
something like that. Think bigger. A lot bigger.)

Menhirs?

Joe

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because
the
beads used to fill the water treatment gadget are called ion
*exchange*
beads or media. The implication is that they have traded one kind
of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever
anions
were originally present, like Cl- or whatever, then a cation exchange
resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual
10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in
freshman
chem
lab all our titrations came out wacky and it turned out the "neutral"
DI
water we were using to dissolve our standards was really pH 2 :-).
Oh,
it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering
capacity
any little contaminant can shift the pH substantially. Any that has
been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

I always wondered just how this was supposed to work. Thanks.

I sounds like in a home system it may be difficult to achieve and
maintain neutral pH, as one or the other bed will always be a bit
ahead.

Joe Gwinn

If you wanted exactly neutral very pure water, yes it would be slightly
tricky. In practice you don't care about exactly neutral pH so it is
easy -
each resin takes out whatever is there of each charge and all that is
left
is water. Yes, a tiny amount of acid or base can shift the pH, but you
don't care precisely because the buffer capacity is so low - any tiny
amount
of anion or cation you add on purpose will be enough to completely swamp
out
any slight initial acidity or alkalinity. It's only when you run it
through
one resin and not the other (or one resin is saturated and the other one
isn't) that you have a problem. Say you start with salt water and all
the
Na+ is exchanged for H+ but the Cl- isn't exchanged for OH-: you just
made
HCl, hydrochloric acid :-).

Ahh. I was worrying about corrosion of for instance copper, and if I
understand the implications of the above, for instance a bit of salt in
the feedwater will cause the deionizer to produce hydrochloric acid,
which will dissolve the copper in no time. People are far more tolerant
of dilute HCl than copper and stainless steel, so what's good enough for
drinking may not be good enough for a boiler et al. I'm sure that there
are better deionizers, but still...

Joe Gwinn

Let me try again. There are two parts to the deionizer, one that removes
cations and one that removes anions. So long as both are working, the water
that comes out is at neutral pH. No acid or base is produced. If there is
table salt in the water, NaCl, the cation portion will remove the Na+ and
release H+, and the anion portion will absorb the Cl- and release OH-.
Since there were equal amounts of Na+ and Cl- to begin with, equal amounts
of H+ and OH- will be released and they will combine to produce water, H2O,
at neutral pH. It is only when one half malfunctions that there is a
problem, and it is easily detected by monitoring the output pH. Deionizers
are a standard way to clean up water for all kinds of applications.

-----
Regards,
Carl Ijames

In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
In article ,
"Carl Ijames" wrote:

"Joseph Gwinn" wrote in message
...
I'm not sure that deionized water is in fact free of ions, because
the
beads used to fill the water treatment gadget are called ion
*exchange*
beads or media. The implication is that they have traded one kind
of
ion for another, not that all ions are removed.

They use an anion exchange resin to substitute OH- ions for whatever
anions
were originally present, like Cl- or whatever, then a cation exchange
resin
to take out positive ions like Na+ and replace them with H+, then (at
neutral pH, anyway) the H+ and OH- form water except for the residual
10-7 M
of each from the dissociation equilibrium. If one of the two beds is
saturated you get either acid or base coming out - one time in
freshman
chem
lab all our titrations came out wacky and it turned out the "neutral"
DI
water we were using to dissolve our standards was really pH 2 :-).
Oh,
it
doesn't matter which bed comes first, and in disposable cartridges the
resins are frequently mixed. Since DI water has no pH buffering
capacity
any little contaminant can shift the pH substantially. Any that has
been
exposed to air for a while will usually be down around pH 5 or so from
dissolved carbon dioxide

I always wondered just how this was supposed to work. Thanks.

I sounds like in a home system it may be difficult to achieve and
maintain neutral pH, as one or the other bed will always be a bit
ahead.

Joe Gwinn

If you wanted exactly neutral very pure water, yes it would be slightly
tricky. In practice you don't care about exactly neutral pH so it is
easy -
each resin takes out whatever is there of each charge and all that is
left
is water. Yes, a tiny amount of acid or base can shift the pH, but you
don't care precisely because the buffer capacity is so low - any tiny
amount
of anion or cation you add on purpose will be enough to completely swamp
out
any slight initial acidity or alkalinity. It's only when you run it
through
one resin and not the other (or one resin is saturated and the other one
isn't) that you have a problem. Say you start with salt water and all
the
Na+ is exchanged for H+ but the Cl- isn't exchanged for OH-: you just
made
HCl, hydrochloric acid :-).

Ahh. I was worrying about corrosion of for instance copper, and if I
understand the implications of the above, for instance a bit of salt in
the feedwater will cause the deionizer to produce hydrochloric acid,
which will dissolve the copper in no time. People are far more tolerant
of dilute HCl than copper and stainless steel, so what's good enough for
drinking may not be good enough for a boiler et al. I'm sure that there
are better deionizers, but still...

Joe Gwinn

Let me try again. There are two parts to the deionizer, one that removes
cations and one that removes anions. So long as both are working, the water
that comes out is at neutral pH. No acid or base is produced. If there is
table salt in the water, NaCl, the cation portion will remove the Na+ and
release H+, and the anion portion will absorb the Cl- and release OH-.
Since there were equal amounts of Na+ and Cl- to begin with, equal amounts
of H+ and OH- will be released and they will combine to produce water, H2O,
at neutral pH. It is only when one half malfunctions that there is a
problem, and it is easily detected by monitoring the output pH. Deionizers
are a standard way to clean up water for all kinds of applications.

I know that total ions must balance to yield zero net charge, but what
caught my eye is the following:

"It's only when you run it through one resin and not the other (or one
resin is saturated and the other one isn't) that you have a problem.
Say you start with salt water and all the Na+ is exchanged for H+ but
the Cl- isn't exchanged for OH-: you just made HCl, hydrochloric acid
:-)."

Ahh. I read the first sentence too fast. OK.

Joe Gwinn