# Electrically conductive glues



## Ludemandan (Jul 13, 2005)

I became intrigued with electrically conductive glue for making RCAs, after Oliver posted about it in another thread. After all, if airplane wings are held on with glue, what's the harm in trying it on RCAs? I've tested two glues, and these are my results.

*First test* 
The first one is called wire glue from a site called Electronic Goldmine. Electronic Goldmine sells a large assortment of usual, unusual and cool geeky stuff. Want a Cold War era Soviet radioactivity meter? They have them.

Anyway, Wire Glue. It is very small, I'd say about half a cubic inch (not to be confused with a cubic half inch). 










It is apparently a mix of water and carbon conductive grease. The instructions even say to add a bit of water if it starts to harden in the container. So far, not so good. 










I let some dry out on a piece of paper and measured the resistance while wet. It registered in the hundreds of thousands of ohms per inch. I should estimate the cross sectional area to be more scientific, but at that reading it doesn't even matter.

Anyway, I kept moving forward with the test. I set up the RCA on a soldering stand (note the irony) and let it dry overnight. The package does not give a drying time. 










The next morning I came out and gave the wire a little tug, and it popped right out of the RCA plug. I didn't even get a chance to listen to it.

Conclusion: Fail. 

*Second test*

This time I decided to try conductive silver epoxy, which I found on Amazon. It also comes in a very small amount. Judging by the price, this looks like more serious stuff. 










Mixing it up on a piece of Raammat backing, it smells pretty bad, but it's obviously metallic. It also takes a long time to dry. You could spend 30 minutes mixing it around if you wanted. There is no hurry to get it set up, like with regular epoxy.










My cheap DMM did not detect any difference in resistance between a short circuit and a circuit across the silver epoxy. From what I can tell, the conductivity is as good as wire.

The package says it takes a couple hours to cure, but the cure time varies greatly with temperature. Since it was a cold day, I decided to give it a blast with the heat gun.










(The above photo may be with the first wire glue, but I did the same thing with the silver epoxy)

I also decided to reinforce this cable with JB Quik. I therefore won't be able to say much about its own holding strength; however, if you are actually making an RCA you would probably reinforce it as well, so it's more like a real world DIY cable.



















That is, besides the fact that I left the ends unfinished for the purpose of the test. 










Again, with the glue dried I measured the same resistance across the RCA as a short circuit. Also, with a decent tug it stays together. 

I plugged my new 3' cable into my garage 12V system. It replaced the cable that normally goes from my source unit to the input equalizer. I switched back and forth playing a bit of test material. 










There was no difference in sound!

Conclusion: This works well. If you were to do a proper shrink finish on the RCAs, your cable would be just as good as any. However, it takes longer, so unless you have a way to hold multiple RCA ends, you have to do them one at a time, and at different times. I'm glad I have this stuff around for situations where soldering is just too challenging, and I would not hesitate to use it in a hi-fi application. But soldering is still the first choice.


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## IDGAF (Dec 27, 2009)

Great write-up. Good info. I'll be getting some of this for those tricky jobs.


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## 94VG30DE (Nov 28, 2007)

Good writeup, thanks for following through. Good information.


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## goodstuff (Jan 9, 2008)

Liking this. I've used some MG Chemicals products before. They are usually very good.
Thanks.


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## emperorjj1 (Sep 10, 2008)

nice...


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## briansz (Feb 5, 2008)

I'd looked at some of the silver-bearing epoxy to 'solder' lead-in tinsels to stripped aluminum voice coil wire.

Ended up getting some solder with a really nasty flux (from Hong Kong) on eBay for about 1/3 the price, and it worked like a charm, so never got to try the epoxy out.


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## Kar Kraftsman (Dec 31, 2010)

Thanks for the info. Nice article.


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## hrv (Mar 21, 2009)

good information, but old stuff like soldering is still the first choice for me to


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## leepersc (Sep 23, 2009)

Great info bud! I have seen this for sale before, but had no idea of a practical application for me. Glad to see it isn't 'snake oil'. Thanks for the great review!


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## rezdawgaudio72 (Apr 9, 2010)

Hay man dats dam cool stuff, have you tried this stuff on speaker tinsel???? I've always had a hard time soldering those,then again nit the best soldering,but got pretty dam good after soldering new power,remote&speaker wire to my O/S PPI M&AM series amps,cool stuff gonna have to try this stuff out,


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## Ludemandan (Jul 13, 2005)

rezdawgaudio72 said:


> Hay man dats dam cool stuff, have you tried this stuff on speaker tinsel???? I've always had a hard time soldering those,then again nit the best soldering,but got pretty dam good after soldering new power,remote&speaker wire to my O/S PPI M&AM series amps,cool stuff gonna have to try this stuff out,


It could definitely work if you have something to hold them while it's setting. I haven't used it on speaker wire connections because I want to be able to try out different speakers without too much trouble.


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## edouble101 (Dec 9, 2010)

Nice test! Thanks


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## emperorjj1 (Sep 10, 2008)

rezdawgaudio72 said:


> Hay man dats dam cool stuff, have you tried this stuff on speaker tinsel???? I've always had a hard time soldering those,then again nit the best soldering,but got pretty dam good after soldering new power,remote&speaker wire to my O/S PPI M&AM series amps,cool stuff gonna have to try this stuff out,


soldering like new speakers you've built or fixing busted ones?


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## steffanan (Dec 9, 2010)

its awesome that you did a real review on it, thanks from everyone who will ever look at this page!


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## Ludemandan (Jul 13, 2005)

2-year update: I've used the silver epoxy on multiple occasions to fix electrical problems in my vehicles. A few weeks ago, a turn signal bulb socket in my Audi fried the contact and stopped working (common problem). MSRP replacement cost: about $50. Scraped it off, applied some silver epoxy, and it's good to go. Just now I was investigating why the horn on my motorcycle stopped working, and I tracked it down to the switch on the handlebar. Scraped off the contacts, reinforced connections with silver epoxy and it works again. Savings: over $100 for the entire left side switch assembly, plus the royal hassle of replacing a part with a wiring harness attached. 

In conclusion, every DIY mechanic should have this stuff in their toolbox.


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