[Lil' Knight]

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

Have you guys experienced this situation?

 

[nikongod]

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.

 

[-=Germania=-]

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.

 

[Lil' Knight]

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

I must have bought some stupid hot glue from eBay

 

[JamesL]

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.

 

[luvdunhill]

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.

 

[jcx]

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

 

[luvdunhill]

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

 

[Navyblue]

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?