About Nichrome Wire
D from BC
Found salt water aquarium heaters so far.
Perhaps I might make my own heater.
I could coil some nichrome wire on glass tubing.
Does a coil of nichrome wire short itself out when the coils touch or
is there a natural insulating oxide on the nichrome wire?
Phil Allison
"D from BC"
> Does a coil of nichrome wire short itself out when the coils touch
** Yes.
> is there a natural insulating oxide on the nichrome wire?
** No.
..... Phil
RogerN
There are cartridge heaters, band heaters, all kinds of heating elements.
How about a power resistor in a glass tube? What are your requirements?
Are you pumping etchant and need it heated in a tube? Lots of
possibilities!
RogerN
"D from BC" <myreal...@comic.com> wrote in message
news:2jojg5tlmskbkcr0j...@4ax.com...
Jon Slaughter
No, generally they are put in ceramics to help distribute the heat for such
things. If you can get some high temp coatings you might be able to use
them. I assume by "etcher" you mean heating up the ferric chloride? If so
then in I imagine you will still need some type of coating as it might be
etched along with your pcb. I tried an "aquarium bubbler" thingamajig that
was made out of sand and it was etched along with the pcb too... Well, at
least some reaction or something took place. It didn't completely ruin it
but screwed it up a little. Similarly I used an aquarium heater and the
coating on it was partially etched(something in the paint I guess).
You might be able to use something like plaster of paris(try to etch a
little and see if it reacts in any negative way just in case). A thin
coating would probably work or you could make a brick or plate with the wire
ran though it in some space filling pattern.
Martin Riddle
Just go to the local pet shop.
There are electronic thermostat submersibles that would work fine for
etching. (just don�t submerge them ;))
Cheers
"D from BC" <myreal...@comic.com> wrote in message
news:2jojg5tlmskbkcr0j...@4ax.com...
Spehro Pefhany
<myreal...@comic.com> wrote:
>I'm now currently Googling for an inline heater for my new pcb etcher.
>Found salt water aquarium heaters so far.
>
>Perhaps I might make my own heater.
Titanium can be used for some etchants, but the $25 glass aquarium
heaters are probably your best bet for something you can buy easily
and will be safe.
>I could coil some nichrome wire on glass tubing.
>Does a coil of nichrome wire short itself out when the coils touch or
>is there a natural insulating oxide on the nichrome wire?
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
Jon Slaughter
> On Sun, 22 Nov 2009 18:02:41 -0800, the renowned D from BC
> <myreal...@comic.com> wrote:
>
>> I'm now currently Googling for an inline heater for my new pcb
>> etcher. Found salt water aquarium heaters so far.
>>
>> Perhaps I might make my own heater.
>
> Titanium can be used for some etchants, but the $25 glass aquarium
> heaters are probably your best bet for something you can buy easily
> and will be safe.
>
>
I got one of those 25$ ones, one of the higher power models. It was not
enough to really get the etchant hot. It got it lukewarm. Of course over
time it would get hotter but generally you don't wanna spend 30 mins just to
heat the stuff up(as you can do it cold in 30 mins).
D from BC
wrote:
>
>There are cartridge heaters, band heaters, all kinds of heating elements.
>How about a power resistor in a glass tube? What are your requirements?
>Are you pumping etchant and need it heated in a tube? Lots of
>possibilities!
>
>RogerN
>
Cartridge heaters are in stainless steel. I can't remember which
etchants don't etch stainless.
The etchant is pumped.
Target temperature is 40C to 55C.
Time of temp rise: Say 10 minutes
Starting temp: 23C
Total etchant volume: 300ml (It's a tiny foutain type.)
I don't have heat capacity for ferric choride, Ammonium P. or Cupric
Chloride.
Assuming of heat capacity of etchant >water:
Then
Specific heat of water = 4.2 J/(K*g)
m= mass= 1g/mL *300mL = 300g
q = 300g x 4.2 x (55C - 23C) = 40320 Joules
Energy = power * time
40320 Joules/(10*60) = 67 Watts
So...I need greater than 67 watts due to heat loss and using the wrong
heat capacity.
Probably double that.. Say 134Watts.
More power would be nice to reduce warm up time.
lektr...@gmail.com
(heater stuff mostly snipped...)
> Probably double that.. Say 134Watts.
> More power would be nice to reduce warm up time.
Two commercial sites for products I've used in the past:
http://www.minco.com/
http://briskheat.com
or you might try Grainger, if they ship to your locale. They have a
wide range of heating products. What about either a warming plate for
keeping cups of coffee hot or heater tape used to keep pipes from
freezing?
None of these suggestions are cheap though...
D from BC
I'm thinking of coiling nichrome wire in a glass tube to insert in the
pump line.
I'm jabbing it into the pump line like I'm doing voodoo on it.
The problem is insulating the nichrome coil such that turnings don't
short. This is not a problem if the coil naturally stretches out a
bit.
But needling the nichrome wire through the center of the coil needs
insulation (capillary tube,woven glass sleeve,maybe teflon tubing)
which I haven't found yet (without buying a case load.)
The construction is like a long very hot radial leaded inductor.
Adrian Tuddenham
Pass the liquid through a container with an electric kettle element.
Having an over-sized element like that won't cause too many problems
unless you want really fine temperature control. The thermal capacity
of the water is much greater than the thermal capacity of the heating
element, so provided your controller has a wide enough proportional
band, it won't overshoot and hunt.
--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
Jon Slaughter
We are not talking about water here...
lektr...@gmail.com
> I'm thinking of coiling nichrome wire in a glass tube to insert in the
> pump line.
> I'm jabbing it into the pump line like I'm doing voodoo on it.
>
> The problem is insulating the nichrome coil such that turnings don't
> short. This is not a problem if the coil naturally stretches out a
> bit.
> But needling the nichrome wire through the center of the coil needs
> insulation (capillary tube,woven glass sleeve,maybe teflon tubing)
> which I haven't found yet (without buying a case load.)
>
> The construction is like a long very hot radial leaded inductor.
So you want to do everything yourself? You can wrap the NC wire
around an insulator (like a piece of glass) so that it's not touching
itself, then insulate it with furnace cement (refractory cement). You
should be able to find this at a hardware store; it's used to patch
bricks in fireplaces and chimineys. Once dry it will hold everything
in place. You'll still need to waterproof this heater if you're going
to insert it into the etchant tank. You can also wrap the NC wire
(again, don't let the coils touch) around a glass tube the etchant is
passing through, then coat it in furnace cement to hold the wire in
place and insulate them. Can you calculate how much current/voltage
you will need? How will you measure/control the temp?
christofire
<lektr...@gmail.com> wrote in message
news:fe7ba799-a0f7-42c3...@o31g2000vbi.googlegroups.com...
* Why not use a ready-made wirewound resistor, or a string of them? ... then
varnishing the wire or whatever they do to insulate adjacent turns has
already been done for you.
Chris
D from BC
I estimate about 200W-300W is needed to raise 300mL of pumped etchant
to a temperature of 50C within 10 minutes.
At this power, I'd probably use the 120VAC here and control the heater
with a light dimmer ghetto style.
I'll be selecting coil and wire dimensions to get 200Watts spread over
as much surface area as my design allows.
In my case, a NC ribbon coiled in a 5mm dia glass tube that is 18cm
long.
ugh.. T regulation..
For now, I'll control the temperature manually. (Turn dimmer dial + IR
probe) :(
I'll design a thermostat with thermocouple at a later time.
D from BC
I suspect I need a red hot nichrome heating element.
Kinda like putting a pot of cold water on a red hot stove element.. It
still takes awhile to reach a boil.
John Fields
wrote:
>I'm now currently Googling for an inline heater for my new pcb etcher.
>Found salt water aquarium heaters so far.
>
>Perhaps I might make my own heater.
>I could coil some nichrome wire on glass tubing.
>Does a coil of nichrome wire short itself out when the coils touch
---
Yes
---
> or is there a natural insulating oxide on the nichrome wire?
---
No.
---
http://www.quartz.com/quartz.html
http://www.usplastic.com/catalog/item.aspx?itemid=23884&catid=799
http://www.ohmite.com/cgi-bin/showpage.cgi?product=270_series
JF
Jim Thompson
I made a Nichrome Plexiglas bender once. It lengthens significantly
when hot. So I mounted it on ceramic stand-offs... one end fixed, one
end spring-loaded to maintain it straight.
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
D from BC
Ha.. Perhaps call it speaking in links..
I get the picture. :)
Thanks
Adrian Tuddenham
Is this primarily water-based or is it an organic fluid? If the former,
it will behave thermally like water - if the latter, your insulating
problems will be a lot simpler but you might need to duplicate the
thermostat with a second overheating cut-out.
D from BC
<To-Email-Use-Th...@My-Web-Site.com> wrote:
>I made a Nichrome Plexiglas bender once. It lengthens significantly
>when hot. So I mounted it on ceramic stand-offs... one end fixed, one
>end spring-loaded to maintain it straight.
>
> ...Jim Thompson
Oh yeah..
I havent considered thermal expansion yet..
http://en.wikipedia.org/wiki/Nichrome
Thermal expansion: 14E-6/C
If I've figured this right..
Say 1000C temp jump on 300cm of nichrome.
(Nichrome melts ~1400C)
(Lf - Li))/Li = alpha*dT
14E-6*1000*300=dL= 4.2cm increase in length
My nichrome coil in a 5mmx180mm glass tube is going to need some room
to creep around.
Rich Webb
wrote:
>On Mon, 23 Nov 2009 12:54:40 -0700, Jim Thompson
If you're still in the stubby pencil phase, you might want to hop over
to http://www.wiretron.com/ and d/l their WireTronic app. It's a free,
handy tool that collects various wire characteristics in one place and
does include info on nichrome and other resistance wires.
--
Rich Webb Norfolk, VA
Jon Slaughter
We are talking about etching metal which generally means any metal device
will be ruined. FeCl is like water(after all, you mix it with part water)
but cannot be contained in any metals(maybe some alloys and stuff like
titanium but not sure). AFAIK the only two methods of effective and
efficient heat distribution would either require metal, which is out of the
question here, or ceramics. Plastics are probably not an option. Of course I
know very little about any specifics so there might be something out there
that works. Glass is something that generally works(is glass classified as a
ceramic?) and is used but it would be hard for D to make something out of
glass that works well I'd imagine.
D from BC
wrote:
Yup..
Alternatively....
I just tripped upon Kanthal wire in my Google travels.
http://en.wikipedia.org/wiki/Kanthal
1) Forms a protective layer of aluminum oxide.
2) Used in heating elements.
Seems like I can tightly coil Kanthal wire without separators or
adding an insulator.
Tim Williams
news:f3plg5d097utkq2e6...@4ax.com...
>> or is there a natural insulating oxide on the nichrome wire?
>
> ---
> No.
Well, there IS, but it isn't insulating against electrons.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms
D from BC
<tmor...@charter.net> wrote:
>"John Fields" <jfi...@austininstruments.com> wrote in message
>news:f3plg5d097utkq2e6...@4ax.com...
>>> or is there a natural insulating oxide on the nichrome wire?
>>
>> ---
>> No.
>
>Well, there IS, but it isn't insulating against electrons.
>
>Tim
Is it Chromium oxide?
RogerN
"D from BC" <myreal...@comic.com> wrote in message
news:03img5dev6ijcf7tt...@4ax.com...
With Kanthal you can melt the copper off the board :-) One of my projects
for the future include a heat treating furnace for hardening and tempering
tool steels. I would need fire brick, Kanthal wire, and a temperature
control. IIRC, I've seen Kanthal heating elements for ceramic kilns on eBay
before. It is high temperature wire but I'm not sure how you are going to
transfer the heat to the etching solution. Is your pump going to pump the
solution through tubing through heating elements? Are you going to have
the heating element in a glass tube going through the solution?
One idea is that you could study the principle behind the instant hot water
heaters and see if you can apply to etching solution. You don't have to use
heating element wire, anything that converts electricity to heat should
work, like a linear voltage regulator and a load resistor, use etchant
running through tubing to cool the regulator and power resistor. For quick
heating you would probably need something with a lot of surface contact
area, maybe make something like a steam engine boiler using glass and/or
plastic tubing.
RogerN
D from BC
wrote:
I plan on putting a 20cm long heating coil in a 6mm dia glass tube in
a 15mm dia PVC etchant pipe.
My construction is loosely based on an automotive block heater
Example:
http://www.fsrproducts.com/pictures/blockheaterlate.jpg
>
>One idea is that you could study the principle behind the instant hot water
>heaters and see if you can apply to etching solution. You don't have to use
>heating element wire, anything that converts electricity to heat should
>work, like a linear voltage regulator and a load resistor, use etchant
>running through tubing to cool the regulator and power resistor. For quick
>heating you would probably need something with a lot of surface contact
>area, maybe make something like a steam engine boiler using glass and/or
>plastic tubing.
>
>RogerN
>
If I spend more time on research, I'll have to make and sell these
heaters on Ebay. :P
Tim Williams
news:4kmmg5htu97alpj0q...@4ax.com...
>>>> or is there a natural insulating oxide on the nichrome wire?
>>
>
Ya- not a renouned conductor, but like stainless steel, it's not very thick,
so it still looks like metal. After using it in a kiln, say, it might be
thicker and a fair insulator (but it'll also be brittle and useless).
Incidentially, most inorganic salts (like Cr2O3) become ionic conductors at
about half their melting point, so hot nichrome is probably a fair conductor
even if it's in good condition.
Adrian Tuddenham
Nichrome wire isn't likely to survive for very long in direct contact
with FeCl, either; especially if thee is a potential difference between
the ends. You need a ceramic or glass-encased element of some sort; but
they are poor thermal conductors,so, for the same heat transfer as
direct metal contact, you will need a much greater surface area or a
higher temperature at the resistance element.
I believe Corning used to make waterproof ceramic heating elements, so
that might be a direction to follow.
Nik Rim
"D from BC" <myreal...@comic.com> wrote in message
news:2jojg5tlmskbkcr0j...@4ax.com...
> I'm now currently Googling for an inline heater for my new pcb etcher.
> Found salt water aquarium heaters so far.
>
> Perhaps I might make my own heater.
> is there a natural insulating oxide on the nichrome wire?
>
What about a halogen lamp tube (the linear type, usually about 4" long).
Then you only have to insulate the ends etc.
They are only a few $$ each. You could even build a "reverse Liebig
condenser" arrangement to house it.
RogerN
Sounds interesting, kind of difficult but interesting!
Anyway, one of my favorite suppliers for that sort of stuff is McMaster
Carr. IIRC they have glass tubing, nichrome wire, ceramics, mica
insulators, PVC tubing, and all sorts of industrial supplies. Their price
is generally fair, they ship fast, and their stuff is almost always in
stock.
I've been playing with temperature controls and such lately, I have an Allen
Bradley PLC 5 programmed to control my electric smoker. Some info that may
be of interest to you. DigiKey sells a 100 Ohm (100 Ohm at 0 Deg.
C)platinum RTD temperature sensor for $13.XX. From what I've been reading
the instrumentation for such, take a 1ma current source to power the RTD
(More current heats RTD more). Also supply a 100 ohm precision resistor
with 1ma. The voltage drop difference would be due to the temperature above
0 deg. C. Then an adjustable comparator for setting temperature to drive
perhaps a solid state relay. An amplifier to detect rate of change can help
with overshoot/undershoot. A few years back I bought a lot of 11 Fuji
temperature controls that read thermocouples or RTD's and drive SSR's, the
lot of 11 controls cost some $130 or so. You might want to check out Ebay
temperature controls after you find out what a headache manual control will
be.
RogerN
Rich Grise
> On Mon, 23 Nov 2009 13:12:37 +1100, "Phil Allison" <phi...@tpg.com.au>
>>
>>> Does a coil of nichrome wire short itself out when the coils touch
>>
>>** Yes.
>>
>>> is there a natural insulating oxide on the nichrome wire?
>>
>>** No.
>>
>
> Alternatively....
> I just tripped upon Kanthal wire in my Google travels.
> http://en.wikipedia.org/wiki/Kanthal
> 1) Forms a protective layer of aluminum oxide. 2) Used in heating
> elements.
>
> Seems like I can tightly coil Kanthal wire without separators or adding an
> insulator.
Why not just go to the aquarium store and get a glass-enclosed tank heater?
Tropical aquaria use sea water, which is also quite corrosive, so I hear.
Or is this more of a training exercise?
Good Luck!
Rich
Rich Grise
>>...
> If I spend more time on research, I'll have to make and sell these
> heaters on Ebay. :P
"What are the characteristics of Hastelloy C-276?
* Excellent corrosion resistance in reducing environments
* Exceptional resistance to strong solutions of oxidizing salts,
such as ferric and cupric chlorides
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ <- [emphasis mine]
* High nickel and molybdenum contents providing good corrosion
resistance in reducing environments
* Low carbon content which minimizes grain-boundary carbide
precipitation during welding to maintain resistance to corrosion in
heat-affected zones of welded joints
* Resistance to localized corrosion such as pitting and
stress-corrosion cracking
* One of few materials to withstand the corrosive effects of wet
chlorine gas, hypochlorite and chlorine dioxide"
http://nickelsteelalloy.com/hastelloy-c-276-c276-nickel-alloy.htm
Have Fun!
Rich
Spehro Pefhany
wrote:
Or he could just take a regular old calrod swaged element, slip it
through an everyday piece of titanium tubing from the junk box and
bend it into a "U". The top ends don't get immersed in the etchant.
Ti is better than Hastelloy for resistance to FeCl.
J.A. Legris
> I'm now currently Googling for an inline heater for my new pcb etcher.
> Found salt water aquarium heaters so far.
>
> Perhaps I might make my own heater.
> I could coil some nichrome wire on glass tubing.
> is there a natural insulating oxide on the nichrome wire?
Please don't etch your own PCBs - you're sure to want double/multiple
layer boards really soon and at that point you'll send them out to
pros, possibly wondering what ever happened to all those noxious
chemicals you poured down the drain before you wised up.
The chemicals are in my coffee, dammit!
--
Joe
J.A. Legris
<speffS...@interlogDOTyou.knowwhat> wrote:
>
> Or he could just take a regular old calrod swaged element, slip it
> through an everyday piece of titanium tubing from the junk box and
> bend it into a "U". The top ends don't get immersed in the etchant.
> Ti is better than Hastelloy for resistance to FeCl.
I used all my titanium scrap on my jet-pack. Would 24K gold tubing
work instead?
--
Joe
D from BC
Like a block heater..
http://www.autopartsfair.com/images/products/engineparts/z6002105690.jpg
Geesh...Who doesn't have titanium tubes in their junk box..
D from BC
wrote:
>Sounds interesting, kind of difficult but interesting!
The worst for me is leak proofing.
>
>Anyway, one of my favorite suppliers for that sort of stuff is McMaster
>Carr. IIRC they have glass tubing, nichrome wire, ceramics, mica
>insulators, PVC tubing, and all sorts of industrial supplies. Their price
>is generally fair, they ship fast, and their stuff is almost always in
>stock.
>
>http://www.mcmaster.com/
>
>I've been playing with temperature controls and such lately, I have an Allen
>Bradley PLC 5 programmed to control my electric smoker. Some info that may
>be of interest to you. DigiKey sells a 100 Ohm (100 Ohm at 0 Deg.
>C)platinum RTD temperature sensor for $13.XX. From what I've been reading
>the instrumentation for such, take a 1ma current source to power the RTD
>(More current heats RTD more). Also supply a 100 ohm precision resistor
>with 1ma. The voltage drop difference would be due to the temperature above
>0 deg. C. Then an adjustable comparator for setting temperature to drive
>perhaps a solid state relay. An amplifier to detect rate of change can help
>with overshoot/undershoot. A few years back I bought a lot of 11 Fuji
>temperature controls that read thermocouples or RTD's and drive SSR's, the
>lot of 11 controls cost some $130 or so. You might want to check out Ebay
>temperature controls after you find out what a headache manual control will
>be.
>
>RogerN
>
I suspect my pcb's will be etched by the time I need to make a manual
temperature adjustment.
However electronic control would be nice.. There is a danger of
vaporizing the etchant.
But yeah.. I'll watch ebay if I need a controller.
D from BC
wrote:
>On Mon, 23 Nov 2009 23:07:50 -0800, D from BC wrote:
Interesting...
Hastelloy tubes for the etchant plumbing.
Might be extra $$$ if I don't like using ~$3 of PVC from the hardware
store.
D from BC
wrote:
I'm trying to design a near tankless mini fountain etching machine.
About 300mL of etchant is used.
About half the etchant is in the plumbing.
There's no room for a floating aquarium heater.
But aquarium inline heaters are available and I might get one of
those.
Spehro Pefhany
Ti tube is maybe forty bucks from McMaster if your junkbox is bare.
D from BC
>
>"D from BC" <myreal...@comic.com> wrote in message
>news:2jojg5tlmskbkcr0j...@4ax.com...
>> I'm now currently Googling for an inline heater for my new pcb etcher.
>> Found salt water aquarium heaters so far.
>>
>> Perhaps I might make my own heater.
>> I could coil some nichrome wire on glass tubing.
>> Does a coil of nichrome wire short itself out when the coils touch or
>> is there a natural insulating oxide on the nichrome wire?
>>
>
>
>What about a halogen lamp tube (the linear type, usually about 4" long).
>Then you only have to insulate the ends etc.
Reminds me of the time I wrapped aluminum tubing around a long halogen
tube.
It was meant to be a source of hot air.
The air pump I used had oily air and the halogen/exchanger would burn
the oil and filled the place up with smoke.
Anyways..
Putting a halogen in the etchant flow had iffy negative points.
1) Maybe the solder joints on the contacts might melt.
2) If #1 then sealed contact terminals are needed.
3) I can't pack it with magnesium oxide to decrease the heater to
glass thermal resistance.
4) The halogen might explode cause I can't do #3
5) I can make a heater with more surface area for faster liquid warm
up.
>
>They are only a few $$ each. You could even build a "reverse Liebig
>condenser" arrangement to house it.
>
Yeah...Doable. Quick. Spacy cause it's glowing glass..
There's more thermal resistance compared to my custom heater design..
A halogen in a liebig will have thermal resistance's from:
bulb gas mix + quartz glass + air gap + liebig glass
My heater design has thermal resistance's from:
0.1mm MagnesiumOxide + 0.8mm thick tube glass
imo..a halogen tube light is still a good contender.
D from BC
I still want fast development iterations.
(I fk up many times.)
Examples:
'make board rev 1..trash...make another board rev 2...trash.. make rev
3...trash.. make rev 4.. trash...etc..
I do make multilayer but not with traditional vias.
I'll google on how to neutralize the waste.
Sorry if your coffee tasting a bit metallic.
D from BC
ha.
Fred Bartoli
Hmmm, FeCl3 has Fe in it. Maybe (wild idea) you can induction heat it?
Ask Tim W. to have a try at it...
--
Thanks,
Fred.
D from BC
I'll guess not as efficiently as a heating element.
Ever see ferric chloride stick to a neo magnet? If my chemistry is not
off then if the molecules won't get drawn to a magnetic field it's
unlikely the ferric chloride molecules or iron ions can be 'jiggled'
by an induction heater under 500watts.
Guessing something to do with electron spin on Fe ions.
And then there's microwave heating.. :P
Rich Grise
You neutralize the chemicals with washing soda (Na2CO3) - this turns it
in to water and, essentially, dirt.
Cheers!
Rich
Spehro Pefhany
Yeah, that's probably the easiest and maybe cheapest way- pyrex tray,
nuke it (in a $39 oven that is reserved for that use) and do your
thing. I've done that myself way back when. Probably work okay even if
you had the PCB in there. Hmm... maybe rig up some baffle thingies and
you could get the carousel to stir it for you.
D from BC
Speaking of wild ideas..
Here's one I've been toying with..
To make a 'ghetto style' etching machine:
Power a rice cooker with H bridge at say.. 10Hz.
This will alternate the magnetic field of the heating coil to move a
encased neomagnet move for etchant agitation.
I just did an experiment by powering my rice cooker with 60VDC (my max
bench supply).
A neomagnet didn't move nor did a small bolt when the supply was
pulsed.
Bummer :(
I might figure out why later.
But all that above craziness can be avoided by buying a chemistry hot
plate/mag stirrer combo. Some ebay ones go for around $50
Tim Williams
> Putting a halogen in the etchant flow had iffy negative points.
> 1) Maybe the solder joints on the contacts might melt.
> 2) If #1 then sealed contact terminals are needed.
> 3) I can't pack it with magnesium oxide to decrease the heater to
> glass thermal resistance.
> 4) The halogen might explode cause I can't do #3
> 5) I can make a heater with more surface area for faster liquid warm
> up.
I wouldn't worry about surface area -- FeCl3 is pretty dark stuff, it'll
absorb light quite nicely. That covers an entire 10% of the heat output.
The rest can be covered by flow. Now, the downside is, the ends will get
hot. Maybe you can backfill the seals with oil?
Tim Williams
news:pan.2009.11.24....@example.net...
>> The chemicals are in my coffee, dammit!
>
> You neutralize the chemicals with washing soda (Na2CO3) - this turns it
> in to water and, essentially, dirt.
Mostly, but the copper is still a heavy metal, and I guess you might've been
careless and dropped solder in there or something at some point.
JosephKK
<myreal...@comic.com> wrote:
>On Mon, 23 Nov 2009 12:54:40 -0700, Jim Thompson
><To-Email-Use-Th...@My-Web-Site.com> wrote:
>
>>I made a Nichrome Plexiglas bender once. It lengthens significantly
>>when hot. So I mounted it on ceramic stand-offs... one end fixed, one
>>end spring-loaded to maintain it straight.
>>
>> ...Jim Thompson
>
>Oh yeah..
>I havent considered thermal expansion yet..
>
>http://en.wikipedia.org/wiki/Nichrome
>Thermal expansion: 14E-6/C
>
>If I've figured this right..
>
>Say 1000C temp jump on 300cm of nichrome.
>(Nichrome melts ~1400C)
>
>(Lf - Li))/Li = alpha*dT
>
>14E-6*1000*300=dL= 4.2cm increase in length
>
>My nichrome coil in a 5mmx180mm glass tube is going to need some room
>to creep around.
Let's jump the track a bit. How about a standard glass heat exchanger
and a hot water loop heated by a regular water heater?
Besides, over 90% of the heat capacity of any aqueous solution is the
water anyway.
JosephKK
The extra $ is one thing, drastically helping with the thermal issues
is another. Sometimes one relatively expensive part hugely improves
product performance.
JosephKK
Back when i started making a PWB was sufficient expense that i could
not afford to make trash. More than one bad version would sink me and
the product.
Perhaps you should transition into commercial software where repeated
failures are better tolerated.
Yes, i am abnormally cranky lately, day job stress.
JosephKK
<tmor...@charter.net> wrote:
>"Rich Grise" <rich...@example.net> wrote in message
>news:pan.2009.11.24....@example.net...
>>> The chemicals are in my coffee, dammit!
>>
>> You neutralize the chemicals with washing soda (Na2CO3) - this turns it
>> in to water and, essentially, dirt.
>
>Mostly, but the copper is still a heavy metal, and I guess you might've been
>careless and dropped solder in there or something at some point.
>
>Tim
Getting solder in the enchant tank? Unlikely, no process need for
them to ever come close. Even process issues that help keep them
separated.
Tim Williams
news:3fuch59ls8qj12l7c...@4ax.com...
> Yes, i am abnormally cranky lately, day job stress.
Your posts are also sucking. The last ten or so posts you've made didn't
show up in the thread they belong in. And they aren't quoting
automatically, I have to type the "> "'s myself.
D from BC
I'm striving to make a compact, low volume etchant fountain.
I believe inserting a 'heating rod' in the plumbing yields a compact
design.
A heat exchanger has more plumbing and therefore will required more
etchant.
Plus.... An element heater can be at hundreds of degrees but an
exchanger is limited to about 100C.
The less etchant ...the faster the warm up.
The hotter the heater.. the faster the warm up..
JosephKK
<tmor...@charter.net> wrote:
>"JosephKK" <quiett...@yahoo.com> wrote in message
>news:3fuch59ls8qj12l7c...@4ax.com...
>> Yes, i am abnormally cranky lately, day job stress.
>
>Your posts are also sucking. The last ten or so posts you've made didn't
>show up in the thread they belong in. And they aren't quoting
>automatically, I have to type the "> "'s myself.
>
>Tim
Very weird. I get to see my newsreader's quoting before i post and it
shows up then and there correctly. Could something else be causing
it? I would like to hear how.
Jim Thompson
Works for me. Quote marks are added by the responder's reader, so
something is hosed on JosephKK's system.
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
You can never be too prepared for the REPRESSION!
Rich Grise
> On Tue, 24 Nov 2009 17:05:00 -0600, "Tim Williams" <tmor...@charter.net>
>>news:pan.2009.11.24....@example.net...
>>>> The chemicals are in my coffee, dammit!
>>>
>>> You neutralize the chemicals with washing soda (Na2CO3) - this turns it
>>> in to water and, essentially, dirt.
>>
>>Mostly, but the copper is still a heavy metal, and I guess you might've
>>been careless and dropped solder in there or something at some point.
>
> ever come close. Even process issues that help keep them separated.
I've heard that the commercial board houses drill the holes, plate up the
copper, and then use the artwork to stencil or screen solder onto the
copper, then etch and the solder acts as resist. I have no idea what
etchant they'd use, or even if it's true, but it sounds like an
interesting and eminently feasible idea.
Thanks,
Rich
John Larkin
Some PCB houses used to use plated solder as the copper etch resist.
John
JosephKK
<To-Email-Use-Th...@My-Web-Site.com/Snicker> wrote:
>On Wed, 02 Dec 2009 22:54:29 -0800,
>"JosephKK"<quiett...@yahoo.com> wrote:
>
>>On Wed, 2 Dec 2009 09:24:01 -0600, "Tim Williams"
>><tmor...@charter.net> wrote:
>>
>>>"JosephKK" <quiett...@yahoo.com> wrote in message
>>>news:3fuch59ls8qj12l7c...@4ax.com...
>>>> Yes, i am abnormally cranky lately, day job stress.
>>>
>>>Your posts are also sucking. The last ten or so posts you've made didn't
>>>show up in the thread they belong in. And they aren't quoting
>>>automatically, I have to type the "> "'s myself.
>>>
>>>Tim
>>
>>Very weird. I get to see my newsreader's quoting before i post and it
>>shows up then and there correctly. Could something else be causing
>>it? I would like to hear how.
>
>Works for me. Quote marks are added by the responder's reader, so
>something is hosed on JosephKK's system.
>
> ...Jim Thompson
Very strange, as soon as i click the reply button the quoted text
shows up in the editor with the new layer of ">" showing. Maybe i
will have to look at my posts in a different newsreader.
They appear to be correct in Google.