ways to isolate silver thread?

Hi,

I've bought some silver condutive thread on ebay, but i start searching about the thread and i found that the thread will oxidize quickly unless i can isolate it. Some pages said that i could use fabric paints or puff paints but i can't find where i live (Lisbon, Portugal) so i thought i could use some clear nail polish, what do you think? My problem about nail polish is the alcohol in it, could the eletricity ignite the alcohol? I personally think that the alcohol will evaporate but im not sure. What do you guys think?

Thank you.

I doubt that the used solvent is alcohol, i go for acton or something similar.
The solvent will be gone after drying, no problem.
Electricity in the used range only produces sparks on shortcut, or on relay contacts.

The oxidation layer will insulate the silver just the same as your nail varnish. Oxidation is only a problem if you want to contact something to the thread.

Much better is the stainless steel thread.

Hi,

Wandall, see this video : Flammability of Nailpolish - YouTube.

Grumpy_Mike, Yes, the passivation layer will protect the silver from the oxidation, but its only 15% Ag, the other 85% i dont know what it is, do you think that the thread will be protected with only 15 % ?

Thank you both.

do you think that the thread will be protected with only 15 % ?

No, what you have is an alloy, it will oxidase all over.

I would not rely on the oxidation for isolation.

Nice video. So nailpolish makes a colorful molotov cocktail.

I still believe it is save if dried. Have you ever seen burning fingernails?

Distance is a good isolator. Used in high voltage power lines.

Whandall, i never saw flammable fingernails but i think its a good experiment xD.

Well yes distance might be a good isolator ( i dont know why) but, my project is using the thread in a t - shirt so distance is impossible.

About the oxidation, its not the oxidation that would isolate, but the passivation of silver.

TiagoPT:
About the oxidation, its not the oxidation that would isolate, but the passivation of silver.

Nope. Oxidation does not mean oxide.

Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion.

Silver is stable in pure air and water, but tarnishes when it is exposed to air or water containing ozone or hydrogen sulfide, the latter forming a black layer of silver sulfide.

Passivation, in physical chemistry and engineering, refers to a material becoming "passive," that is, being less affected by environmental factors such as air and water. Passivation involves a shielding outer-layer of base material, which can be applied as a microcoating, or oxidation which occurs spontaneously in nature. As a technique, passivation is the use of a light coat of a protective material, such as metal oxide, to create a shell against corrosion.

I see, i 've failed, thank you for the explanation, so i really need to get some kind of pcb protective coat?

But like grumpy said, i need stainless thread, maybe i will get some near me.

I think stainless material will be too rigid, but check it out.

Whandall:
I think stainless material will be too rigid, but check it out.

No it's not, it is like a thick cotton, you can sew with it and is very flexible. The only snag is that it feels a bit rough to the touch as it has whiskers, which can short adjacent threads if they are too close. Don't go closer that 1/8". These whiskers are invisible to the naked eye but you can see them under a microscope.

Hi again,

i finally found a good place to buy the stainless stell thread, so i can move to the actual project, but this is my first project and i dont have any skills at this moment. Could you guys help me?

My project consists of a t-shirt with leds and a heartbeat sensor, when the heart beats the arduino flash some leds and when the heart rests it blinks other leds.

like this: - YouTube

I´ve bought everything rom ebay, so my arduino its not official, so its different from the one on that video.

Another guy (from the portuguese forum) gave me some links: The "GettingStartedProject" – World Famous Electronics llc.
and : GitHub - WorldFamousElectronics/PulseSensor_Amped_Arduino: PulseSensor Arduino code for BPM and Processing-Visualizer .

But those are for arduino uno right? or will it run on lillypad? and since my arduino lilypad has more i/o holes i can have more leds right?

my lilypad : http://i.imgur.com/kCXHWCy.jpg

What do you guys think?
Thank you.

will it run on lillypad?

Yes.

since my arduino lilypad has more i/o holes i can have more leds right?

Yes but watch the current, you won't be able to run LEDs on all of those at 20mA

how do i know how much leds can the arduino hold on? (5mm leds)

how do i know how much leds can the arduino hold on?

It depends on what processor your knock off Arduino has. Do you know what you have?

it says on the chip : atmel mega328p AU 1527

While the individual pins can sink or source 20mA there are restrictions on the collective total of the overall chip.
The data sheet says:-

Although each I/O port can sink more than the test conditions (20 mA at VCC = 5V, 10 mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed:
ATmega48PA/88PA/168PA/328P:
1] The sum of all IOL, for ports C0 - C5, ADC7, ADC6 should not exceed 100 mA.
2] The sum of all IOL, for ports B0 - B5, D5 - D7, XTAL1, XTAL2 should not exceed 100 mA.
3] The sum of all IOL, for ports D0 - D4, RESET should not exceed 100 mA.
If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test condition.

Although each I/O port can source more than the test conditions (20 mA at VCC = 5V, 10 mA at VCC = 3V) under steady state conditions (non-transient), the following must be observed:
ATmega48PA/88PA/168PA/328P:
1] The sum of all IOH, for ports C0 - C5, D0- D4, ADC7, RESET should not exceed 150 mA.
2] The sum of all IOH, for ports B0 - B5, D5 - D7, ADC6, XTAL1, XTAL2 should not exceed 150 mA.
If IIOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current greater than the listed test condition.

Over and above that the limit on the Vcc pin is 200mA. So it is complex.

since im new to arduino and eletronics, this is a complex thing to understand at least for me.

What i undestand was that each pin can output 20 mA, and since each led can hold 20 mA i think this is ok,

i understood very little information from the text because i dont know what that ports means but the sum of pins should not exceed 100 mA?

And you said that the limit on the "vcc pin" what is that?

And you said that the limit on the "vcc pin" what is that?

The power supply for the chip. So 200mA is the most a chip can supply but the can not be distributed just any way.

i understood very little information from the text because i dont know what that ports means

A port is 8 input / output pins. You must determine what pins correspond to what port before you can make sense of this requirement.

What i undestand was that each pin can output 20 mA, and since each led can hold 20 mA i think this is ok,

This is not OK, despite what you think.