开云体育

Roy wrote.....The practical problem is controlling the feed of a large drill enlarging a hole; they tend to self feed at their spiral rate..........

I believe this is only true with lever operated machines, such as drill presses. Using the screw operated tailstock and only opening up by 1/64" at a time should be very little problem. If necessary, the lips could be 'backed' off in the same fashion as brass drills. Of course, the quill travel is limited, so it's a case of drilling a bit, move the tailstock a bit.
HTH
Ellis

Anyone else having problems trying to download files in the files
section?

On Thursday 05 April 2007, roylowenthal wrote:

Yup! That's the same sodium bisulphate as the pH down product for
pools/spas. It's quicker than alum (any of the common variants) &
easy to get.

Thankee Sir! Will head down there tomorrow, I only have a little of
that left in the homebrew supplies. Time to stock up for another batch
anyway. Unfortunately too late in the year to lager another batch out
on the balcony :(.

Take care, Vikki.

[ ... ]
Found this at my local homebrew store:

Would that work?
[ ... ]

--
Victoria Welch, WV9K/7
"War is an ugly thing, but not the ugliest of things." --John S. Mill

Reaming it provides a smooth bore & ensures it's actually as big as
it claims to be.

Roy

--- In 7x12minilathe@..., "born4something" <ajs@...>
wrote:

Hi Dan,

No such thing as a dumb question - unless you don't ask it! In that
vein, I'll ask my dumb question. If you have a 7x12 lathe, why do
you need to enlarge the spindle bore to fit 3/4" through? The off-
the-shelf bore is 20mm so you have very nearly 1mm to spare. Do you
have a burr or am I missing something?

John


--- In 7x12minilathe@..., "jumbo75007" <fullerdj@>
wrote:

AHH, good explaination. I understand the reason now.
Thanks,
Dan Fuller
Carrollton, Texas


--- In 7x12minilathe@..., "roylowenthal"

<roylowenthal@>

wrote:

A reamer takes less power to drive. For making the hole, a

drill

would do just as well, except a 13/16" drill bit requires more

torque

than the lathe can deliver; that's why drill bits cut more
aggressively than reamers.

Roy

--- In 7x12minilathe@..., "jumbo75007" <fullerdj@>
wrote:

The practical problem is controlling the feed of a large drill
enlarging a hole; they tend to self feed at their spiral rate. It's
easier to control a reamer's feed.

Roy

--- In 7x12minilathe@..., "Ellis Cory" <ellis103@...> wrote:

Roy wrote..........A reamer takes less power to drive. For making the

hole, a drill would do just as well, except a 13/16" drill bit requires
more torque than the lathe can deliver..........

I'm not sure this is the full story. Reamers are fed at a much lower

rate and cutting speed. If a drill was fed at the same or slower rate,
then the cut could be made.

HTH
Ellis

[Non-text portions of this message have been removed]

--- In 7x12minilathe@..., Victoria Welch <wrlabs@...>
wrote:

Embarrassed to admit what chemistry I did take has long since been
forgotten <blush>.

Hi Vikki,

Well, I didn't mention that when I sat my last chemistry exam I
burnt all my lecture notes BEFORE the results came back. No way I
was repeating that subject even if they did let me back!

Thirty odd years on, I design and manufacture industrial ozone
generating equipment. I still don't understand the chemistry but I
can tear O2 molecules apart with brute force (high voltages) and
even do titrations to measure the output with a recipe / cheat
sheet, courtesy of an industrial chemist on the west coast. But
understand it? What was Seargent Schultz's famous line?

John

Yup! That's the same sodium bisulphate as the pH down product for
pools/spas. It's quicker than alum (any of the common variants) &
easy to get.

Roy

--- In 7x12minilathe@..., Victoria Welch <wrlabs@...>
wrote:

On Thursday 05 April 2007, Ian Foster wrote:

G'day Jeff, Andy, et al.
I'm not quite sure by your comments whether you have used Sodium
Bisulphate to extract broken taps. If you have then that
substantiates my assessment that it is the sulphate ions which do

the

work. Being a bisulphate the iron ions do not need to displace the
sodium ions to form sodium hydroxide (corrosive to aluminium),

they

just neutralise the solution forming iron sulphate and sodium
sulphate.
[ ... ]

Found this at my local homebrew store:

productid=285&cat=0&page=1

Would that work?

Convenient place to get to (something special in Seattle) and I do
already go there from time to time.

Embarrassed to admit what chemistry I did take has long since been
forgotten <blush>.

Thanks & take care, Vikki.
--
Victoria Welch, WV9K/7
It is my reading of history that Allah usually favours the army

with the

best firepower.-- The Warlord (_Ivory_, Mick Resnick)

Ian,

Am no chemist but have used Sodium Bisulphate (meta too I think) for
broken drills etc in gold, silver, and aluminium. For aluminium somewhat
dilute nitric would be faster but much harder to obtain these days and not
nearly as safe from a handling aspect. For gold and silver it saved my
reputation on a number of occasions in commercial shops.

Jeff

* REPLY SEPARATOR *

On 4/5/2007 at 11:37 PM Ian Foster wrote:

G'day Jeff, Andy, et al.
I'm not quite sure by your comments whether you have used Sodium
Bisulphate to extract broken taps. If you have then that
substantiates my assessment that it is the sulphate ions which do the
work. Being a bisulphate the iron ions do not need to displace the
sodium ions to form sodium hydroxide (corrosive to aluminium), they
just neutralise the solution forming iron sulphate and sodium
sulphate.

In my discussions it can sound like the ions making up the repective
salts just combine in solution, this is not the case. The solution is
just a soup of dissociated ions which don't come together until they
become insoluble, either by their inherent properies (as for
insoluble salts like calcium carbonate) or by concentatration which
leads to crystalisation (as for common salt, sodium chloride).

In Oz you can readily obtain Sodium Metabisulphate for sterilising
home brew gear and for fruit preservation, Ive used it myself in that
role. The metabisulphate may have too high a pH to be effective.

Andy! Here's another chemical to test. Safer than making Gun Cotton!

One good turn deserves another.
Regards,
Ian

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@...>
wrote:

Ian,

For some more info to confuse the chemistry freaks... the

jewellery

pickle is labelled " Sodium Bisulfate". The PH down might be

a 'sodium meta

bisulfate' but it is reported to be a cleaner (and cheaper)

replacement for

the jewellery standard Sparax brand. A totally different chemical

than alum

but it has worked for me in the past and is always available in my

studio.

Jeff

Be sure to check out for small mills and
lathes.
Yahoo! Groups Links





--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.446 / Virus Database: 268.18.26/746 - Release Date: 4/4/2007

1:09 PM


-
Demand Designs
Analog/Digital Modelling & Goldsmithing


jdemand@...
-

On Thursday 05 April 2007, Ian Foster wrote:

G'day Jeff, Andy, et al.
I'm not quite sure by your comments whether you have used Sodium
Bisulphate to extract broken taps. If you have then that
substantiates my assessment that it is the sulphate ions which do the
work. Being a bisulphate the iron ions do not need to displace the
sodium ions to form sodium hydroxide (corrosive to aluminium), they
just neutralise the solution forming iron sulphate and sodium
sulphate.
[ ... ]

Found this at my local homebrew store:



Would that work?

Convenient place to get to (something special in Seattle) and I do
already go there from time to time.

Embarrassed to admit what chemistry I did take has long since been
forgotten <blush>.

Thanks & take care, Vikki.
--
Victoria Welch, WV9K/7
It is my reading of history that Allah usually favours the army with the
best firepower.-- The Warlord (_Ivory_, Mick Resnick)

G'day Jeff, Andy, et al.
I'm not quite sure by your comments whether you have used Sodium
Bisulphate to extract broken taps. If you have then that
substantiates my assessment that it is the sulphate ions which do the
work. Being a bisulphate the iron ions do not need to displace the
sodium ions to form sodium hydroxide (corrosive to aluminium), they
just neutralise the solution forming iron sulphate and sodium
sulphate.

In my discussions it can sound like the ions making up the repective
salts just combine in solution, this is not the case. The solution is
just a soup of dissociated ions which don't come together until they
become insoluble, either by their inherent properies (as for
insoluble salts like calcium carbonate) or by concentatration which
leads to crystalisation (as for common salt, sodium chloride).

In Oz you can readily obtain Sodium Metabisulphate for sterilising
home brew gear and for fruit preservation, Ive used it myself in that
role. The metabisulphate may have too high a pH to be effective.

Andy! Here's another chemical to test. Safer than making Gun Cotton!

One good turn deserves another.
Regards,
Ian

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@...>
wrote:

Ian,

For some more info to confuse the chemistry freaks... the

jewellery

pickle is labelled " Sodium Bisulfate". The PH down might be

a 'sodium meta

bisulfate' but it is reported to be a cleaner (and cheaper)

replacement for

the jewellery standard Sparax brand. A totally different chemical

than alum

but it has worked for me in the past and is always available in my

studio.

Jeff

Ian,

For some more info to confuse the chemistry freaks... the jewellery
pickle is labelled " Sodium Bisulfate". The PH down might be a 'sodium meta
bisulfate' but it is reported to be a cleaner (and cheaper) replacement for
the jewellery standard Sparax brand. A totally different chemical than alum
but it has worked for me in the past and is always available in my studio.
The Ph stuff will have to wait for testing... 6" of white shit today and
probably another 6" by morning, good thing I didn't store the snow blower
quite yet. Vermont CAN be interesting if you have a really twisted sense of
humour ;-)

Jeff

* REPLY SEPARATOR *

On 4/5/2007 at 10:15 PM Ian Foster wrote:

G'day Andy,
Perhaps you could do a few extra-curricular experiments.
Drill a hole in pieces of aluminium and then drive steel screws into
into each then. No need to thread the hole. Not quite the same as our
problem because there are no flutes for the electrolyte to pass
through; this may require some thought, eg grind flats on the side of
the screws.
I'd start with the cheapest and most readily accessible alum. Or get
what ever varieties are available and do comparative tests, hence the
number of pieces.

The trouble is we leave such experimentation until it is life and death
not an experiment.

Some how I think the straight aluminium sulphate may he the best. As I
said in an rearlier post the aluminium ions would deposit out of the
solution as Aluminium Hydroxide, whilst the hydroxides of potasium and
ammonia are water soluble and would attack the native aluminium.
But only experimentation will tell.

One good turn deserves another.
Regards,
Ian






Be sure to check out for small mills and
lathes.
Yahoo! Groups Links





--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.446 / Virus Database: 268.18.26/746 - Release Date: 4/4/2007

1:09 PM


-
Demand Designs
Analog/Digital Modelling & Goldsmithing


jdemand@...
-

G'day Andy,
Perhaps you could do a few extra-curricular experiments.
Drill a hole in pieces of aluminium and then drive steel screws into
into each then. No need to thread the hole. Not quite the same as our
problem because there are no flutes for the electrolyte to pass
through; this may require some thought, eg grind flats on the side of
the screws.
I'd start with the cheapest and most readily accessible alum. Or get
what ever varieties are available and do comparative tests, hence the
number of pieces.

The trouble is we leave such experimentation until it is life and death
not an experiment.

Some how I think the straight aluminium sulphate may he the best. As I
said in an rearlier post the aluminium ions would deposit out of the
solution as Aluminium Hydroxide, whilst the hydroxides of potasium and
ammonia are water soluble and would attack the native aluminium.
But only experimentation will tell.

One good turn deserves another.
Regards,
Ian

Thanks, Ian. My chemistry stopped with school "A-level" (the exams that qualify you for uni). We had opportunities for extra-curricular experiments making gun-cotton, benzedrine etc. Much more exciting than the H & S regulated stuff that they do now. Do you reckon "any old alum" will do the trick for taps stuck in aluminium, or should I be looking for "potash alum" or "ammonium alum"?

Andy





---------------------------------
Now you can scan emails quickly with a reading pane. Get the new Yahoo! Mail.

Hi Jeff,

What a neat idea. After the work's been buggered I can save the tap
to present to the tool store as evidence!

Yeah, Ian sorted me out on that. But I'm still not repeating CHEM-
101. <G>

John


--- In 7x12minilathe@..., "Jeff Demand" <jdemand@...>
wrote:

John,

No, you want the acid PH down. Remember that alkaline stuff eats
aluminium. Unless you really want to save the tap rather than the

work ;-)

Jeff

* REPLY SEPARATOR *

On 4/5/2007 at 4:41 AM born4something wrote:

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@>
wrote:

And don't drink it, tastes awful and will rot your teeth ;-).

Hi Jeff,

How about dentures? <G>

More seriously, would I be correct in assuming this bag of

Alkalinity

Increaser I have in the corner would be the same stuff?

John

-
Demand Designs
Analog/Digital Modelling & Goldsmithing


jdemand@...
-

John,

No, you want the acid PH down. Remember that alkaline stuff eats
aluminium. Unless you really want to save the tap rather than the work ;-)

Jeff

* REPLY SEPARATOR *

On 4/5/2007 at 4:41 AM born4something wrote:

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@...>
wrote:

And don't drink it, tastes awful and will rot your teeth ;-).

Hi Jeff,

How about dentures? <G>

More seriously, would I be correct in assuming this bag of Alkalinity
Increaser I have in the corner would be the same stuff?

John

-
Demand Designs
Analog/Digital Modelling & Goldsmithing


jdemand@...
-

G'day John.
Had a few of those passes as well, Pure Mathematics if I recall, they
didn't want to risk seeing me back.
But I got through.
I had to dig the chemistry text book out when I got involved in
corrosion control, only made a little bit more sense! I have always
enjoyed metallurgy (just to bring us back to topic).

One good turn deserves another.
Regards,
Ian

--- In 7x12minilathe@..., "born4something" <ajs@...>
wrote:

You won't be surprised to hear I got a "terminating pass" in
chemistry at uni. What's that? It's a grade the School of Chemistry
conceeds to non-chemical engineers that meets the chemistry pre-
requisites for ANY engineering subject OUTSIDE of the school of
Chemistry. It ensured they didn't have me repeat the subject.

'nuff said?

John

Hi Ian,

Oops, I misread Jeff's reference to "Ph down for swimming pools" as
reducing acidity. Not quite right, eh? In fact, dead wrong.

I have to confess to my Achilles heal here. I have an electrical
engineering degree (even with honours!) but that came from a love of
electrons. Once you introduce protons and neutrons they're
contaminated and my eyes glaze over. You won't be surprised to hear
I got a "terminating pass" in chemistry at uni. What's that? It's a
grade the School of Chemistry conceeds to non-chemical engineers
that meets the chemistry pre-requisites for ANY engineering subject
OUTSIDE of the school of Chemistry. It ensured they didn't have me
repeat the subject.

'nuff said?

John



--- In 7x12minilathe@..., "Ian Foster" <fosterscons@...>
wrote:

Oh no John, No John, No John, No!

G'day all, (had to include that!)
Alkalinity increaser will raise the pH whereas Alum lowers the pH.

You

want a very ionic solution with a low pH which will attack the

iron

without attacking the aluminiun oxide. Whilst aluminium is more
electropositive than iron its oxide protects it from attack by the

acid

radicals. To help, aluminium sulphate is insoluble and forms a
protective coating also. (This does not apply to aluminum sulfate
unless you stir vigourously.) Interestingly the Electrolytic Zinc

works

in Hobart Tas. would not allow gavanized steel cable ladder but

would

allow aluminium due to the suphurous atmosphere.

I have wondered whether Ammonium Sulphate would also work, it is

quite

corrosive to iron and is available as a fertiliser (as are most of

my

comments). If you could get it withour raising suspicsion,

ammonium

nitrate might also work.

BTW, Alum is a styptic which causes blood to clot, if your barber

cuts

you he will have a bottle of alum solution to apply to the cut.

One good turn deserves another.
Regards,
Ian

--- In 7x12minilathe@..., "born4something" <ajs@>

wrote:

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@>
wrote:

And don't drink it, tastes awful and will rot your teeth ;-).

Hi Jeff,

How about dentures? <G>

More seriously, would I be correct in assuming this bag of

Alkalinity

Increaser I have in the corner would be the same stuff?

John

G'day Andrew
I think it is the sulphate ions which do the damage to the iron. Both
iron and aluminium are trivalent so this could help the reaction.
Corrosion of the iron would be helped by it being an alloy so there
would be galvanic couples on the iron/electrolyte interfacee at which
accelerated erosion would occur. The aluminium ions in the
electrolyte could be deposited as Aluminium Hyroxide leaving iron and
sulphate ions.
That's about the limit of my chemistry knowledge. Some years back I
was involved in Cathodic Protection and have maintained some interest
in corrosion matters since; few people seem to have any grasp of it
or be aware of the issues involved.

Regarding brass: There is a real risk that the zinc would be eroded
from the brass preferentially to the copper in the alloy. You need an
acid ion which would form insoluble and impervious salts with both
copper and zinc; off hand I can't think of one. I think Copper
Chloride is only partially soluble so it is possible that a zinc
chloride solution could be used. It would need to be neutral so
Killed Spirits of Salts may be the answer. A strong solution of
common salt, Sodium chloride, might be worth a try. At least with
brass the galvanic couple between the copper (in the alloy) and the
iron would mean erosion of the iron.

Regarding Yorkshire and Urine: It has been said that Yorkshire men
are full of .... and wind, far be it for me to reinforce that! Urine
was also collected by dyers (a name in my ancestry) because it acts
like alum to fix dyes in cloth)

One good turn deserves another.
Regards,
Ian



--- In 7x12minilathe@..., andrew franks <andyf1108@...>
wrote:

I've been following this thread with interest; it's been ages

since I broke a tap in aluminium, so it's bound to be my turn again
soon. I have been trying to find out what alum actually is. "True
alum" seems to be the double sulphate of aluminium and either
potassium or ammonia *, whereas "papermaker's alum" seems to be just
hydrated aluminum sulphate. Which of these "alums" will attack taps
broken off in aluminium, or will any of them work?

And will the process work for brass, too?

* apparently, there was once a thriving trade in human urine here

in the UK, to supply the Yorkshire alum makers with ammonia, when
they weren't burning seaweed to get potassium!

Andy

I've been following this thread with interest; it's been ages since I broke a tap in aluminium, so it's bound to be my turn again soon. I have been trying to find out what alum actually is. "True alum" seems to be the double sulphate of aluminium and either potassium or ammonia *, whereas "papermaker's alum" seems to be just hydrated aluminum sulphate. Which of these "alums" will attack taps broken off in aluminium, or will any of them work?
And will the process work for brass, too?

* apparently, there was once a thriving trade in human urine here in the UK, to supply the Yorkshire alum makers with ammonia, when they weren't burning seaweed to get potassium!

Andy


Ian Foster <fosterscons@...> wrote:
Oh no John, No John, No John, No!

G'day all, (had to include that!)
Alkalinity increaser will raise the pH whereas Alum lowers the pH. You
want a very ionic solution with a low pH which will attack the iron
without attacking the aluminiun oxide. Whilst aluminium is more
electropositive than iron its oxide protects it from attack by the acid
radicals. To help, aluminium sulphate is insoluble and forms a
protective coating also. (This does not apply to aluminum sulfate
unless you stir vigourously.) Interestingly the Electrolytic Zinc works
in Hobart Tas. would not allow gavanized steel cable ladder but would
allow aluminium due to the suphurous atmosphere.

I have wondered whether Ammonium Sulphate would also work, it is quite
corrosive to iron and is available as a fertiliser (as are most of my
comments). If you could get it withour raising suspicsion, ammonium
nitrate might also work.

BTW, Alum is a styptic which causes blood to clot, if your barber cuts
you he will have a bottle of alum solution to apply to the cut.

One good turn deserves another.
Regards,
Ian

--- In 7x12minilathe@..., "born4something" <ajs@...> wrote:

--- In 7x12minilathe@..., "Jeff Demand" <jdemand@>
wrote:

And don't drink it, tastes awful and will rot your teeth ;-).

Hi Jeff,

How about dentures? <G>

More seriously, would I be correct in assuming this bag of Alkalinity
Increaser I have in the corner would be the same stuff?

John

---------------------------------
Copy addresses and emails from any email account to Yahoo! Mail - quick, easy and free. Do it now...

Roy wrote..........A reamer takes less power to drive. For making the hole, a drill would do just as well, except a 13/16" drill bit requires more torque than the lathe can deliver..........

I'm not sure this is the full story. Reamers are fed at a much lower rate and cutting speed. If a drill was fed at the same or slower rate, then the cut could be made.
HTH
Ellis