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dadiOH 03-04-2008 12:15 PM

Badly behaving brass
 
I used to have a wooden sail boat that was made in the 30s. There
were several forged iron rings on various spars and I was told that
the way to get them on was to make the ring with a slightly smaller
inside dimension than the OD of the spar at th desird ring position,
grease the spar, heat the ring, position the ring on the spar and then
toss a bucket of water on it. The ring shrinks and is forever at the
correct place.

Well, lately I have been making myself a new cane. The shaft is
hickory, head mahogany. The shaft is reduced into a shouldered
spindle where it goes into the head. I wanted a transitional
pretty-pretty between the two different woods and decided to use
brass. A piece of 3/4" brass pipe is just the right outside diameter
but the inside diameter was a bit too small to get over the spindle so
I decided to try the heat & quench method ala spar rings.

I cut off a 5/8" wide piece of the pipe to use as my ferrule and
heated it up to see if it would expand enough to get over my spindle.
The dang thing didn't get any bigger; in fact, the ID *decreased*.
Huh? I thought about that for a moment and decided that the wall of
the brass ring must be expanding both outward and inward and therefore
the ID was decreasing, OD increasing.

But then I started thinking about what would happen if I cut the brass
ring and flattened it out into a strip. That strip would be 5/8"
wide, about 1/8" thick and 3+" long. Heat that and each dimension
should increase but the length would increase most, right? Bend that
now elongated piece of brass back into a ring and the ID should be
bigger, right? So why did my piece of pipe decrease in ID when I
heated it?

--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico




Aardvark 03-04-2008 12:35 PM

Re: Badly behaving brass
 
On Tue, 04 Mar 2008 12:15:10 +0000, dadiOH wrote:

> I used to have a wooden sail boat that was made in the 30s. There were
> several forged iron rings on various spars and I was told that the way
> to get them on was to make the ring with a slightly smaller inside
> dimension than the OD of the spar at th desird ring position, grease the
> spar, heat the ring, position the ring on the spar and then toss a
> bucket of water on it. The ring shrinks and is forever at the correct
> place.
>
> Well, lately I have been making myself a new cane. The shaft is
> hickory, head mahogany. The shaft is reduced into a shouldered spindle
> where it goes into the head. I wanted a transitional pretty-pretty
> between the two different woods and decided to use brass. A piece of
> 3/4" brass pipe is just the right outside diameter but the inside
> diameter was a bit too small to get over the spindle so I decided to try
> the heat & quench method ala spar rings.
>
> I cut off a 5/8" wide piece of the pipe to use as my ferrule and heated
> it up to see if it would expand enough to get over my spindle. The dang
> thing didn't get any bigger; in fact, the ID *decreased*. Huh? I
> thought about that for a moment and decided that the wall of the brass
> ring must be expanding both outward and inward and therefore the ID was
> decreasing, OD increasing.
>
> But then I started thinking about what would happen if I cut the brass
> ring and flattened it out into a strip. That strip would be 5/8" wide,
> about 1/8" thick and 3+" long. Heat that and each dimension should
> increase but the length would increase most, right? Bend that now
> elongated piece of brass back into a ring and the ID should be bigger,
> right? So why did my piece of pipe decrease in ID when I heated it?
>
> --
>
> dadiOH
> ____________________________
>
> dadiOH's dandies v3.06...
> ...a help file of info about MP3s, recording from LP/cassette and tips &
> tricks on this and that. Get it at http://mysite.verizon.net/xico


Sounds like a bit of a metallurgical mystery.

Stop trying to figure it out and buy yourself a tap-and-die set from a
local hardware outlet. Thread both the brass ferrule and the last 15mm
(5/8" in old money) of the cane using the coarsest thread in the set then
screw the pair together. Some type of waterproof glue between the two
wouldn't go amiss.

HTH.

--
Liverpool. European City Of Culture 2008
http://www.liverpool08.com

philo 03-04-2008 01:25 PM

Re: Badly behaving brass
 

"dadiOH" <dadiOH@guesswhere.com> wrote in message
news:i3bzj.7700$1_.2952@trnddc02...
> I used to have a wooden sail boat that was made in the 30s. There
> were several forged iron rings on various spars and I was told that
> the way to get them on was to make the ring with a slightly smaller
> inside dimension than the OD of the spar at th desird ring position,
> grease the spar, heat the ring, position the ring on the spar and then
> toss a bucket of water on it. The ring shrinks and is forever at the
> correct place.
>
> Well, lately I have been making myself a new cane. The shaft is
> hickory, head mahogany. The shaft is reduced into a shouldered
> spindle where it goes into the head. I wanted a transitional
> pretty-pretty between the two different woods and decided to use
> brass. A piece of 3/4" brass pipe is just the right outside diameter
> but the inside diameter was a bit too small to get over the spindle so
> I decided to try the heat & quench method ala spar rings.
>
> I cut off a 5/8" wide piece of the pipe to use as my ferrule and
> heated it up to see if it would expand enough to get over my spindle.
> The dang thing didn't get any bigger; in fact, the ID *decreased*.
> Huh? I thought about that for a moment and decided that the wall of
> the brass ring must be expanding both outward and inward and therefore
> the ID was decreasing, OD increasing.
>
> But then I started thinking about what would happen if I cut the brass
> ring and flattened it out into a strip. That strip would be 5/8"
> wide, about 1/8" thick and 3+" long. Heat that and each dimension
> should increase but the length would increase most, right? Bend that
> now elongated piece of brass back into a ring and the ID should be
> bigger, right? So why did my piece of pipe decrease in ID when I
> heated it?
>



http://www.newton.dep.anl.gov/askasc...0/phy00741.htm


I don't know what an exception is but you seem to have found one.

An old mechanics trick to removing semi-monolithic nuts has always been to
heat them
as they will expand just slightly more than the bolt

>
> dadiOH
> ____________________________
>
> dadiOH's dandies v3.06...
> ...a help file of info about MP3s, recording from
> LP/cassette and tips & tricks on this and that.
> Get it at http://mysite.verizon.net/xico
>
>
>




Whiskers 03-04-2008 04:18 PM

Re: Badly behaving brass
 
On 2008-03-04, dadiOH <dadiOH@guesswhere.com> wrote:

[...]

> I cut off a 5/8" wide piece of the pipe to use as my ferrule and
> heated it up to see if it would expand enough to get over my spindle.
> The dang thing didn't get any bigger; in fact, the ID *decreased*.
> Huh? I thought about that for a moment and decided that the wall of
> the brass ring must be expanding both outward and inward and therefore
> the ID was decreasing, OD increasing.


[...]

What instrument did you use to measure the internal diameter? Is it
perchance made of a substance that expands when it gets hot, such as when
measuring a lump of hot metal? ;))

(There's an apocryphal story that 'experts' refused to accept that
materials expand and contract with temperature, and could prove it by using
the very best brass rulers ...).

I suggest that you try the technique using bits of wood and tubing that
you can afford to spoil, before doing it to the new cane, so that you can
get the proportions right.

Sounds like a nice project :)) (My favourite walking-stick is made of
ash with a horn handle - but I didn't make it myself).

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~

Jerry McBride 03-04-2008 05:58 PM

Re: Badly behaving brass
 
Aardvark wrote:

> On Tue, 04 Mar 2008 12:15:10 +0000, dadiOH wrote:
>
>> I used to have a wooden sail boat that was made in the 30s. There were
>> several forged iron rings on various spars and I was told that the way
>> to get them on was to make the ring with a slightly smaller inside
>> dimension than the OD of the spar at th desird ring position, grease the
>> spar, heat the ring, position the ring on the spar and then toss a
>> bucket of water on it. The ring shrinks and is forever at the correct
>> place.
>>
>> Well, lately I have been making myself a new cane. The shaft is
>> hickory, head mahogany. The shaft is reduced into a shouldered spindle
>> where it goes into the head. I wanted a transitional pretty-pretty
>> between the two different woods and decided to use brass. A piece of
>> 3/4" brass pipe is just the right outside diameter but the inside
>> diameter was a bit too small to get over the spindle so I decided to try
>> the heat & quench method ala spar rings.
>>
>> I cut off a 5/8" wide piece of the pipe to use as my ferrule and heated
>> it up to see if it would expand enough to get over my spindle. The dang
>> thing didn't get any bigger; in fact, the ID *decreased*. Huh? I
>> thought about that for a moment and decided that the wall of the brass
>> ring must be expanding both outward and inward and therefore the ID was
>> decreasing, OD increasing.
>>
>> But then I started thinking about what would happen if I cut the brass
>> ring and flattened it out into a strip. That strip would be 5/8" wide,
>> about 1/8" thick and 3+" long. Heat that and each dimension should
>> increase but the length would increase most, right? Bend that now
>> elongated piece of brass back into a ring and the ID should be bigger,
>> right? So why did my piece of pipe decrease in ID when I heated it?
>>
>> --
>>
>> dadiOH
>> ____________________________
>>
>> dadiOH's dandies v3.06...
>> ...a help file of info about MP3s, recording from LP/cassette and tips &
>> tricks on this and that. Get it at http://mysite.verizon.net/xico

>
> Sounds like a bit of a metallurgical mystery.
>
> Stop trying to figure it out and buy yourself a tap-and-die set from a
> local hardware outlet. Thread both the brass ferrule and the last 15mm
> (5/8" in old money) of the cane using the coarsest thread in the set then
> screw the pair together. Some type of waterproof glue between the two
> wouldn't go amiss.
>
> HTH.
>


Nice... didn't think of that... on the other hand how about drying the crap
out of the cane? Then fit your brass ring like you want and give it a dip
in some water... the cane swells and... it's permanent.


--

Jerry McBride (jmcbride@mail-on.us)

eadg 03-04-2008 09:29 PM

Re: Badly behaving brass
 

"Whiskers" <catwheezel@operamail.com> wrote in message
news:slrnfsqths.95k.catwheezel@ID-107770.user.individual.net...
> On 2008-03-04, dadiOH <dadiOH@guesswhere.com> wrote:
>
> [...]
>
>> I cut off a 5/8" wide piece of the pipe to use as my ferrule and
>> heated it up to see if it would expand enough to get over my spindle.
>> The dang thing didn't get any bigger; in fact, the ID *decreased*.
>> Huh? I thought about that for a moment and decided that the wall of
>> the brass ring must be expanding both outward and inward and therefore
>> the ID was decreasing, OD increasing.

>
> [...]
>
> What instrument did you use to measure the internal diameter? Is it
> perchance made of a substance that expands when it gets hot, such as when
> measuring a lump of hot metal? ;))
>
> (There's an apocryphal story that 'experts' refused to accept that
> materials expand and contract with temperature, and could prove it by
> using
> the very best brass rulers ...).


For the OP http://hypertextbook.com/physics/thermal/expansion/ , it's a
comparison chart for various metals...brass moves a reasonable amount, but
if you scroll down it's interesting to note the amount of expansion in
Concorde during flight. It's even painted with expanding paint (o:
Oh, and measuring instruments are always calibrated at a defined
temperature, out of that range, it's unreliable.

>
> I suggest that you try the technique using bits of wood and tubing that
> you can afford to spoil, before doing it to the new cane, so that you can
> get the proportions right.


That's what I would do, but to be honest, I struggle trying to replace the
head of the yardbrush everytime it breaks ;)

>
> Sounds like a nice project :)) (My favourite walking-stick is made of
> ash with a horn handle - but I didn't make it myself).
>
> --
> -- ^^^^^^^^^^
> -- Whiskers
> -- ~~~~~~~~~~


My weapon of choice is a Leki hiking pole: strong, light alloy construction,
telescopic, and with a removeable wooden head so you can use it as a monopod
for a camera.

--
SR



Tommy McClure 03-10-2008 06:42 PM

Re: Badly behaving brass
 

dadiOH wrote:
> I used to have a wooden sail boat that was made in the 30s. There
> were several forged iron rings on various spars and I was told that
> the way to get them on was to make the ring with a slightly smaller
> inside dimension than the OD of the spar at th desird ring position,
> grease the spar, heat the ring, position the ring on the spar and then
> toss a bucket of water on it. The ring shrinks and is forever at the
> correct place.
>
> Well, lately I have been making myself a new cane. The shaft is
> hickory, head mahogany. The shaft is reduced into a shouldered
> spindle where it goes into the head. I wanted a transitional
> pretty-pretty between the two different woods and decided to use
> brass. A piece of 3/4" brass pipe is just the right outside diameter
> but the inside diameter was a bit too small to get over the spindle so
> I decided to try the heat & quench method ala spar rings.
>
> I cut off a 5/8" wide piece of the pipe to use as my ferrule and
> heated it up to see if it would expand enough to get over my spindle.
> The dang thing didn't get any bigger; in fact, the ID *decreased*.
> Huh? I thought about that for a moment and decided that the wall of
> the brass ring must be expanding both outward and inward and therefore
> the ID was decreasing, OD increasing.
>
> But then I started thinking about what would happen if I cut the brass
> ring and flattened it out into a strip. That strip would be 5/8"
> wide, about 1/8" thick and 3+" long. Heat that and each dimension
> should increase but the length would increase most, right? Bend that
> now elongated piece of brass back into a ring and the ID should be
> bigger, right? So why did my piece of pipe decrease in ID when I
> heated it?



brass has a pos coeff of expansion: see
http://en.wikipedia.org/wiki/Coeffic...rmal_expansion
your wood probably expanded more than brass ferrule, ice it

--
tm




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