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Specialty Chemistry Forums => Citizen Chemist => Topic started by: maxvortex on October 20, 2013, 03:01:09 PM

Title: carbon rod and... carbon rod
Post by: maxvortex on October 20, 2013, 03:01:09 PM
Hi !

I have just two questions for a start :-)

1.) What is the difference between carbon rod from battery and carbon rod used for drawing ?

2.) How to make normal carbon electrically conductive ?

Max
Title: Re: carbon rod and... carbon rod
Post by: billnotgatez on October 20, 2013, 07:50:17 PM
as best as I can tell from the internet

writing carbon in pencils is graphite and clay
carbon rods in batteries is made with graphite and a binder

that is my best guess
I could not find any thing for batteries directly

By the way from WIKI

There are several allotropes of carbon of which the best known are graphite, diamond, and amorphous carbon.

Maybe you can do some more research and find the definitive answer

Title: Re: carbon rod and... carbon rod
Post by: vmelkon on October 27, 2013, 06:39:30 PM
Just to add to the above, when I heated pencil cores, there is some oily liquid that comes out and burns. The left over core is crumbly.

It is the same for carbon rod from batteries.
Title: Re: carbon rod and... carbon rod
Post by: curiouscat on October 28, 2013, 12:46:29 AM
They probably use a binder. That might be the oily liquid.
Title: Re: carbon rod and... carbon rod
Post by: maxvortex on November 03, 2013, 02:14:06 PM
Any link to this "oily binder " ?
I found this : http://students.chem.tue.nl/ifp40/Binders.htm and it looks as good way to start. Now we have to define how to make the binding process.

E.g. i have graphite powder and i want to make 5x5 cm graphite electrode.
Can this be done using oil binder and then again, will this hold...

Title: Re: carbon rod and... carbon rod
Post by: curiouscat on November 03, 2013, 02:53:45 PM
Any link to this "oily binder " ?
I found this : http://students.chem.tue.nl/ifp40/Binders.htm and it looks as good way to start. Now we have to define how to make the binding process.

E.g. i have graphite powder and i want to make 5x5 cm graphite electrode.
Can this be done using oil binder and then again, will this hold...

Tar? Pitch? Some sort of resin?
Title: Re: carbon rod and... carbon rod
Post by: billnotgatez on November 03, 2013, 07:17:00 PM
If you are making your own carbon electrode from graphite
Do you think crazy glue (super glue etc.) would work
Title: Re: carbon rod and... carbon rod
Post by: maxvortex on November 04, 2013, 12:30:42 PM
Do you think crazy glue (super glue etc.) would work
***
No it will not. I tested with all kind of glue. non of them worked.
You will get conductive "line" but the outer surface is not conductive and you have no real bonds. I think that they are using some kind of different method to develop this..
Title: Re: carbon rod and... carbon rod
Post by: curiouscat on November 04, 2013, 12:33:34 PM
My suspicion is when you use tar / pitch etc. and bake them at high temp. a lot of them may yield conductive by products. So you get binding with good conductive contact too.
Title: Re: carbon rod and... carbon rod
Post by: HCB on November 21, 2013, 11:55:40 PM
Hello.  I'm not sure what your end product is to be but...

For the metal fabrication world there are Carbon rods used for arc-air gouging.  They are approximately 14 inches long and vary in diameter.  I have bought some which are 1/4 inch diameter and used them for electrolysis tinkering.  The rods I bought had a copper jacket which is easily removed by scoring with a knife and then peeling the copper jacket like pulling the skin off a fish...if you've ever skinned a fish like a catfish.  If not, it's like peeling a protective skin off a LCD screen.  Not hard to do.

Regardless, you can get Carbon rods which conduct electricity easily this way.  Readily available from a welding supply shop (I bought mine off-the-shelf from a local welding supply shop in my tiny (5k population, one-horse town).

However, I have no idea how they are formed: are they cored, pressed, or glued?  I do not know.  But they work well for electrolysis of water.  The formation process would matter to you if you require a specific size/shape, which I can not help with, unfortunately.

--HC
Title: Re: carbon rod and... carbon rod
Post by: maxvortex on November 30, 2013, 06:00:08 AM
@HCB
The idea is to use this carbon electrodes in battery design.
One part of the electrode would be metal and the other carbon.
The main problem is that i need flat surface and i need quite big amount of this electrodes.
Electrode is used as current collector. Can you tell me the prize of your electrodes, where did you buy it ?


@others
I was trying to get/buy tar resin in my country but it's almost impossible because all is based on bitumen.
So i was thinking to make some of this tar on my own but it looks like it's not that simple project.
Accept to make something like: http://www.youtube.com/watch?v=zv0JMKbFsrQ

Any other idea or link where this can be bought ?
Title: Re: carbon rod and... carbon rod
Post by: curiouscat on November 30, 2013, 08:26:44 AM
@others
I was trying to get/buy tar resin in my country but it's almost impossible because all is based on bitumen.
So i was thinking to make some of this tar on my own but it looks like it's not that simple project.

Oh what has the world come to!

What country is this where buying a bit of tar / pitch has become a problem? You really shouldn't have to make your own tar.
Title: Re: carbon rod and... carbon rod
Post by: maxvortex on November 30, 2013, 03:36:36 PM
Almost any European country :-). You can get tar for boat repair but it's quite expensive on the other hand there is ecological issue so that's why they switch to bitumen. Before cca 5 years there was no problem but now bitumen is first choice.

Anyway, i made some pine tar like the guy in yt video.
The process is quite simple and you can easy improve the production.
I mixed carbon with this tar and am gonna let it dry in oven.
I will pass the results tomorrow.

Title: Re: carbon rod and... carbon rod
Post by: curiouscat on December 01, 2013, 12:27:09 AM
Almost any European country :-). You can get tar for boat repair but it's quite expensive on the other hand there is ecological issue so that's why they switch to bitumen. Before cca 5 years there was no problem but now bitumen is first choice.

Bitumen should work fine too I think.
Title: Re: carbon rod and... carbon rod
Post by: 408 on December 01, 2013, 02:58:28 AM
Can you tell me the prize of your electrodes, where did you buy it ?


I pay around 20$ for a box of at least 30 foot long 1/4 inch rods.  I cannot find the box but there is a lot in there, I think they are sold by weight as a similar sized box of the 1/8th rods weigh the same at the same price.  Go to a welding store and ask for graphite gouging rods.
Title: Re: carbon rod and... carbon rod
Post by: maxvortex on December 01, 2013, 07:30:38 AM
Bitumen:
As far as i know bitumen is based on petroleum, and tar on charcoal ( stone ), so i down know if this would work.
Chemical ingredients are different.

Tell me, would it be possible to make tar from some other tree then pine and how much ?

Test:
- i mixed pine tar with carbon powder and i must say that result is quite good.
- the electrical resistance is bigger then in industry based production but i think that this can be solved by hard press and heating.
- conductivity is good to very good and the most important part , i can make the flat electrode.


Title: Re: carbon rod and... carbon rod
Post by: maxvortex on December 01, 2013, 12:41:36 PM
I forget to ask one more thing...
If i heat pine resin on destructive distillation way, what would i get ?
Would i get the same as making d.d. of pine coal/wood ?
Title: Re: carbon rod and... carbon rod
Post by: curiouscat on December 01, 2013, 01:40:28 PM


Tell me, would it be possible to make tar from some other tree then pine and how much ?


I think most wood would work though the exact consistency etc. of the product would change. All you need is a heat and absence of air.