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Conductive Glue And Conductive Thread: Make an LED Display and Fabric Circuit That Rolls Up.

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Step 1: Make Conductive Glue, Conductive Paint, and Conductive Ink

Picture of Make Conductive Glue, Conductive Paint, and Conductive Ink
translucent-glue.jpg
glue-vials.jpg

To make your own conductive glue, you will be taking an insulator (Liquid Tape rubber or DAP Contact Cement) and turning it into an electrical conductor. This is done by the addition of carbon graphite powder which is a conductor. As the binder (LT or DAP) sets up, the carbon crystal flakes stack on each other and intertwine to make the glue conductive. The result is a flexible conductive glue that will stick well to most things.

The glass circuit doodle in pic3 below, is used to illustrate some of the ways the different glues can be used. Click on the comment squares for details.

Since my first instructable on how to make conductive glue: http://www.instructables.com/id/EYA7OBKF3JESXBI/ I have been experimenting with various conductive materials. In the process, I have come up with a few new mixes using other binders that have somewhat different characteristics than the original conductive rubber glue.

Materials


Performix (tm) liquid tape, black-Available at Wal-Mart or http://www.thetapeworks.com/liquid-tape.htm

DAP "The Original" Contact Cement- available at Wal-Mart or most hardware stores.

Carbon Graphite, fine powder- Available in larger quantities at http://www.elementalscientific.net/
Available in smaller quantities at your local hardware store. It's called lubricating graphite and comes in small tubes or bottles. The brand I used is called AGS Extra Fine Graphite, but no doubt there are other brands that will also work.

Conductive thread-Available in small spools at http://members.shaw.ca/ubik/thread/order.html
or at:
http://www.sparkfun.com/commerce/categories.php?cPath=2_135

Clear contact cement such as Welder Contact Adhesive or Goop- available at Wal-Mart and hardware stores

Tuloul solvent- available at hardware stores

WARNING- All of these mixes involve strong solvents that evaporate into the air quickly. Do this only in a VERY WELL VENTILATED room. The fumes can be harmful. Better yet, do it outside.

All of the mixes below are best mixed in small quantities and used immediately. I have tried storing them in airtight containers but all of them seem to harden up after just a few days. Mix them in a stainless steel or glass container. You can mix them in plastic cups, but you will have to do it fast as most of them will dissolve many plastics.

Glue mix #1 Conductive Glue Using Liquid Tape (LT)
This is the original formula that uses a mix of Liquid Tape and Graphite powder. It results in a flexible conductive rubber that actually shrinks as the solvents evaporate, thus tightening it around whatever it coats. It has the lowest resistance of any of the unfibered mixes (32 ohms per inch). For details on how I measured the resistance see the original instructable (link) on this glue. I find it best for gluing wire to wire, or wire to conductive thread or conductive fabric. It can also be used to make conductive foam (see step 4).

Mix the glue 1-1/2 Graphite to 1 Liquid Tape by volume. Mix it fast in small quantities and use it fast as it tends to evaporate and skin up rather quickly.
I usually use 1/4 teaspoon as my unit of volume.

Mix #2 Conductive Paint Using Liquid Tape
This is the same mix as above with the addition of extra solvent to make it the consistancy of thick paint. Because it is a thinner mix, it has a higher resistance (60 ohms per inch) than the conductive glue. It is useful for making conductive thread and conductive fabric (see step 6). It also sticks better to glass than the thicker glue above.

Mix the paint 1-1/2 Graphite to 1 Liquid Tape to 1 Tuloul by volume.

Mix #3 Conductive Ink Using Liquid Tape
I mainly use this ink for touch up if the glue lines get too sloppy or to re-coat close together joints. Because it is so thinned out, it can have a rather high resistance in the hundreds of ohms per inch. It can also be used to create thin film high value resistors and It may be useful for high voltage applications.

Mix the ink 1-1/2 Graphite to 1 Liquid Tape to 3 Tuloul by volume.

Mix #4 Conductive Glue Using Dap Contact Cement
It turns out that most contact cements will become conductive if you add graphite. Even Elmers rubber cement has very low resistance when mixed with graphite. It is however, a raw latex rubber and I do not trust its longevity as raw rubber tends to deteriorate with time.

The DAP Contact Cement is a more industrial strength rubber and it had the lowest resistance of any of the heavy duty contact cements that I tested. While Its resistance is higher (62 ohms per inch) than the Liquid Tape glue. Its biggest advantage is that it does not shrink as much as the LT glue. It is also much more flexible than anything else I tried. This makes it ideal for coating the surface of fabrics without making them curl, to create conductive fabrics, potentiometers, resistors, switches and sockets.

Mix the DAP Contact Cement glue 1-1/2 Graphite to 1 Dap.

Mix #5 Translucent Conductive Glue.
See pic 3B. While I have so far been unable to come up with a clear conductive glue, this is as close as I have gotten. In all of the glues I have been making, I have resisted adding metal powders, or graphite fibers to increase the conductivity, as this makes the glue much more brittle or stiffer. I am trying to keep all the glues flexible as this makes for more interesting possibilities in what can be made conductive. So instead of stiff fibers such as graphite fibers or metal wire, I added flexible conductive thread. And yes, I know, you could just run the thread and skip the glue, but this has interesting artistic possiblilites.

The translucent glue is simply conductive thread that has been unraveled and chopped up into 1/4 inch long pieces. It is then mixed with a clear contact cement such as Welders or Goop. With Welders Contact Cement, I obtained a conductivity as low as 12 ohms per inch.

Mix the translucent glue 1/4 teaspoon clear contact cement with 6 to 12 inches of unraveled and chopped up conductive thread.

Mix #7 Resistor Glue
Mix the resistor glue 1/2 Graphite to 1 Dap contact cement by volume
Less than 1/2 units of graphite can result in a very high resistance or even an insulator.

 
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ToolNut2 months ago

DUDE! You just saved me $175... An hour ago, I thought I was going to have to buy a new dishwasher or spend the $$ on a replacement input panel. The electronic ribbon that connects the push button controls to the motherboard was corroded in several places. Fond this article, scrounged around to find contact cement and lubricating graphite in the shop, and 30 minutes later the dishwasher is running like new. FWIW: I scraped of the plastic and corrosion until I had good conductor exposed (its super thin, so I think I scraped away some good stuff too), laid down the wire glue mixture with a tooth pick. A few of them merged together while I was applying, but they were easy to separate using a new toothpick after the glue had set up about half way. Anyway, thanks for writing this up and sharing. Saved a long evening of manual dish-washing (the horror...).

Zobot8 months ago

Is how safe is it to make and use? Would it be suitable for this project? http://www.popsci.com/article/diy/light-your-love-life-diy-electric-valentine

saket bhardwaj10 months ago
is the glue and paint water resistant
mikey77 (author)  saket bhardwaj10 months ago
Yes it is.

In a fairly thick coating, it should be fairly waterproof.
emartin181 year ago
The old version of this site was better. Flipping through pages is so annoying now.

Worst layout ever.
tandava2 years ago
Have you experimented with using an epoxy glue for added strength?
kamaljassal4 years ago
We still awaits your reply.

Do your paint stripper would also strips the silver ink which we do use before electrofoaming.

please revert asap.

one querry that makes us able Do your paint stripper would also strips the silver ink which we do use before electrofoaming
chrispix4 years ago
I'd like to lay down conductive strips on a door, but the lengths are long, and the glue alone would create too much resistance. If I used the conductive glue to attach conductive thread to the door, would that effectively reduce the resistance over a longer distance (say a few feet) to the resistance of the thread?
ddarko5 years ago
Great instructable! I'm curious as to how much heat this could produce and how quickly. I'd like to use this on a fabric which I want heated to approx 30 degrees but it needs to heat up and cool down to ambient temperature pretty quickly, in a matter of a seconds. Does this sound achievable using typical batteries considering the modest temperature requirement? I'm willing to experiment but would really appreciate a professional opinion on the matter.
nap705 years ago
Your instructable helped me convert my nice dance pads for my (now deceased) PS2 to work on my Xbox 360. My kids are so happy! My kids are DDR fanatics. I bought them nice dance pads for the PS2 a long time ago. After the PS2 died, I got the game with pad for the 360. The kids hate the pad that comes with the game. But no one seems to make the nicer pads for the 360. So I decided to open up the pads to see what I can learn. The two are basically the same design, even the traces line up. But I had no idea how to attach the plastic sensor to the circuit board. A google search for conductive adhesive led me here. I'm so glad it worked. I still have to convert the other dance pad. I will try to make an instructable for that and link to this article.
jdrews6 years ago
Thanks for your instructable mikey77!

As a sidenote:
If any of you have trouble finding "Tuloul solvent", I believe it's a typo. I think it's Tuluol solvent, or more commonly known as Toluene. Here's a wikipedia page:
http://en.wikipedia.org/wiki/Toluene