Capacitor Guts or Glue?

[christarak]

This is the 3rd one I've worked on, and they all have this hard gunk. I'm glad its glue, and now to scrape away what I can. Thanks Jazz.

[christarak]

And just for the future, you'll know if it's cap guts. They stink to high heaven if they're fresh. And if not, it's usually seen as a light-colored powder or crust that gets left behind when the electrolyte dries away. If they explode there'll be bits or rolls of aluminum foil in the immediate vicinity.

And yeah, I'd hesitate to use anything colored black on a circuit board... I'm with Mr. Bass on the "clean up what you can" thing.

Justin

Yes, I've seen the aftermath of an exploding electrolytic, and the burst pimple from the old brown paper caps. This goop had me concerned, so thank you

[christarak]

I've always wondered where these so-called 'free radicals' come from.

HA! I didn't even notice that!

[christarak]

It's the same colour, just thicker and thinner parts.

[christarak]

When you see it up close it doesn't look or feel like hot glue stick. I'd say it was much runnier when applied and its dried much harder than a hot glue.

[christarak]

That's spot on

[christarak]

Thanks guys for your support, and good humour, once again.

[Pedro Vecino]

I have always wanted to know which brand sells that type of adhesive. Does anyone know the name they usually have (composition, tradename?).
Thanks!

[christarak]

Hi Pedro. I don't think I would recommend it. Its obviously messy, and dries so hard that its difficult to unglue the cap. I still like to use "Silastic" (an Australian brand name for a silicon sealant).

[Helmholtz]

I still like to use "Silastic" (an Australian brand name for a silicon sealant).

Silastic is a trademark of Dow Corning/Dow Chemical for a product family of silicone elastomers.
In electronics silicones which release acetic acid (smell of vinegar) should be avoided.

[christarak]

In electronics silicones which release acetic acid (smell of vinegar) should be avoided.

Oh. I didn't know that. Do you know the reason? Is it a corrosive action of acetic acid? What would you recommend as an adhesive to secure large capacitors?

[Helmholtz]

Is it a corrosive action of acetic acid?

Exactly that. You don't want acid fumes in electronics. There are special silicones for use with electronics which don't release acetic acid, e.g. GE Silicones RTV 162Q. But I am sure that also Dow Corning has something suitable in their Silastic product family.

[christarak]

Exactly that. You don't want acid fumes in electronics. There are special silicones for use with electronics which don't release acetic acid, e.g. GE Silicones RTV 162Q. But I am sure that also Dow Corning has something suitable in their Silastic product family.

Excellent. Every single time I come on this Forum I learn something new. vielen dank, Helmholtz.