Silicone sealant (electronics grade)

[sweesiong78]

Has anyone used this for securing parts around their boards:
http://www.ebay.com/itm/704-High-Temperature-Electronic-Devices-Silicon-Rubber-Adhesive-Sealant-Glue-45g-/121428794352?pt=LH_DefaultDomain_0&hash=item1c45b85bf0


I was looking for electronics grade silicon on amazon but they were either super expensive or brands like Permatex which are acid curing.

[nanofrog]

GE Silicone II you can find locally is suitable for electronics use.

[sweesiong78]

Thanks!

[nixfu]

Most manufacturers just use "Hot Snot" aka hot glue. 

[Timmay]

Non-acidic is essentially the pivot point for non-electronics grade silicon and electronics grade silicon, in general. GE Silicone II is good to go, but you will find others. Just check the MSDS for acidic compounds and for more advanced sealants conductive compounds which is required for some to make perfect grounds on aircraft aluminum, yes that is a bit above and beyond but since I have used sealants specific to grounding I figured I would mention it.

[ConKbot]

Your normal every day RTV silicone is 'Condensation cured' where atmospheric moisture is what makes it cure.  There are 3 general kinds. Acetoxy cure, which is the cheapest, bonds well, but releases acetic acid on curing (the acid ingredient in vinegar) And corrodes copper and lots of other metal. Even sealing an enclosure with it, the trapped fumes inside can corrode the items.  The other two kinds are neutral cure, but still slightly different.  Oxime cure which releases a ketone on curing. This can corrode copper on contact, but isnt as bad to use near electronics, just not directly on copper.  The most desirable for electronics is Alkoxy cure, which releases methanol. Mind the fumes from all of them, but if you have a large surface area covered, Acetic acid fumes can be pretty nasty. Though your nose will give you plenty of warning that something isnt right.

The GE silicone II, as mentioned, is generally available locally (at least in the US) and is Alkoxy cure, so +1 to nanofrog on that being a good choice. 

[nanofrog]

Your normal every day RTV silicone is 'Condensation cured' where atmospheric moisture is what makes it cure.  There are 3 general kinds. Acetoxy cure, which is the cheapest, bonds well, but releases acetic acid on curing (the acid ingredient in vinegar) And corrodes copper and lots of other metal. Even sealing an enclosure with it, the trapped fumes inside can corrode the items.  The other two kinds are neutral cure, but still slightly different.  Oxime cure which releases a ketone on curing. This can corrode copper on contact, but isnt as bad to use near electronics, just not directly on copper.  The most desirable for electronics is Alkoxy cure, which releases methanol. Mind the fumes from all of them, but if you have a large surface area covered, Acetic acid fumes can be pretty nasty. Though your nose will give you plenty of warning that something isnt right.

The GE silicone II, as mentioned, is generally available locally (at least in the US) and is Alkoxy cure, so +1 to nanofrog on that being a good choice.

Ticks the right boxes in the US at least (suitability, easy to find, and inexpensive). 

[wraper]

Most manufacturers just use "Hot Snot" aka hot glue.

Only if they are One Hung Low. Hot glue is completely unreliable, will fall off by itself after a few years maximum. Also it is completely unsuitable if it will be exposed to high or low temperatures.

[sweesiong78]

IS one hung low a racist joke?

[ConKbot]

IS one hung low a racist joke?

[codaroma]

I bought Dowsil 1080 which says "Electrical Grade" and "Electrical/ Electronic Devices" on the tube. But beware it is an Oxime cure sealant and so is corrosive to copper.

[codaroma]

As far as I am aware there are 4 main types of silicone sealant
Acetoxy cure - releases acetic acid (vinegar), very corrosive to lots of metals including copper.
Oxime cure - releases either methyl ethyl ketoxime or dimethyl ketoxime (these are not ketones, but oximes, unlike what ConKbot says), these can corrode copper.
Alkoxy cure - releases an alcohol, either methanol or ethanol, does not corrode copper.
Acetone cure - releases acetone (also know as dimethyl ketone, this is nail varnish remover, and is a ketone), does not corrode copper. Not good with some plastics
The last 3 are classed as neutral cure.
Useful resource -> https://cht-silicones.com/download/446