Conductive glue?
Nov 11, 2008 at 6:59 PM Thread Starter Post #1 of 9

Lil' Knight

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I wonder if there's any kind of glue like that?
It's because when I made some interconnects, before using the glue gun, I used the multimeter carefully to make sure there's no bridging. However, after I used the glue gun to seal the solder joints, the multimeter told me that there were some bridging. That really made me mad
frown.gif


Have you guys experienced this situation?
 
Nov 11, 2008 at 7:07 PM Post #2 of 9

nikongod

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It depends on the glue. some glues are HIGHLY conductive, others are "medium" and then of course we have stuff that has guaranteed dielectric strengths for a given thickness.

One of the readily available 24-hour epoxies specifies its dielectric strength on its spec sheet, which is rare for a non-electronic specific product. Sorry, I cant remember which.

As another thought: If the leads & wires are close together and uninsulated at that point it is possible they moved during gluing.
 
Nov 11, 2008 at 7:36 PM Post #3 of 9

-=Germania=-

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That is why I believe in using epoxy. Epoxy gives low to no pressure on the joints and really secures everything. You do need to be much more careful about applying, but gives a better result overall IMO.

BTW: The quote is pretty funny nikongod.
 
Nov 11, 2008 at 7:59 PM Post #4 of 9

Lil' Knight

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Quote:

Originally Posted by nikongod /img/forum/go_quote.gif
As another thought: If the leads & wires are close together and uninsulated at that point it is possible they moved during gluing.


Look like the issue is here. I use some small heatshrink to insulate the solder joints and then gluing. This time there's no bridging
confused.gif

I must have bought some stupid hot glue from eBay
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Nov 11, 2008 at 8:02 PM Post #5 of 9

JamesL

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I've used epoxies that were conductive...

Glue gun is good because it's made of a copolymer with low dielectric constant.
My guess is that there was some kind of mechanical failure.
 
Nov 11, 2008 at 11:26 PM Post #6 of 9

luvdunhill

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I've found some hot glue that is conductive. I think I bought it at Hobby Lobby. I'd make sure to ohm out the stick before using. The proper thing to use is silicone adhesive, preferably electronics grade RTV.
 
Nov 12, 2008 at 3:00 AM Post #7 of 9

jcx

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rtv silicones are not recommended for electronic encapsulation - they release acetic acid as they cure

I'd also be suprised if common hot melt glues are conductive - it usually takes a high loading of conductive particles that contact throughout the matrix to get appreciable conductivity
 
Nov 12, 2008 at 4:39 AM Post #8 of 9

luvdunhill

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Quote:

Originally Posted by jcx /img/forum/go_quote.gif
rtv silicones are not recommended for electronic encapsulation - they release acetic acid as they cure

I'd also be suprised if common hot melt glues are conductive - it usually takes a high loading of conductive particles that contact throughout the matrix to get appreciable conductivity



no. The specific RTV I'd recommend is RTV 162.

According to the datasheet, "Non-corrosive. Bond capacitors, resistors and integrated circuits to PCBs' seals exposed wires, faying surfaces, connectors. Meets MIL-A-46146B. UL HB recognition."

More information is here:

RTV Silicones >> Electronics grade >> White, 1 Part Paste, RTV Silicone Adhesive Sealant
 
Nov 21, 2008 at 4:28 PM Post #9 of 9

Navyblue

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I tested a glue stick that is lying around and it is about 1.5M ohms across about 3" long. Within a plug where distance is say, 1/20", from calculation the resistance would be down to about 25k ohms.

I am also looking at a non-conductive glue, preferably epoxy, anyone has one to recommend?
 

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