Removing rubbery potting compound

Sam Goldwasser wrote in news: snipped-for-privacy@ampersand.seas.upenn.edu:

I think you need a tin of grey rubbery stuff remover.

Go back to your TARDIS.

HeHeHe... Do you charge BIG BUCKs for that advice, huh? :)

And, it probably rots internal organs.....

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pencil

glue.

is

in the

I seem to remember using a 1/8 inch ball mill in a Dremmel for that sort of stuff, localised heat and tugging action hepled in removing from surfaces, . But still time consuming and you have to know there is no little vital stuff buiried within it.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

Sam Goldwasser wrote in news: snipped-for-privacy@ampersand.seas.upenn.edu:

Oh yeah, I should, given what anything seems to cost the moment I need it...

Here's some for free though. Try snagging a bit and burning it, melting it, putting it in chemicals, and comparing to some knowns. If it's silicone you're SOL but a lot of other stuff might be attacked while the rest of the parts sit looking as if they enjoy it because a lot of PCB washes are strong stuff and most parts are designed to resist a lot. If you find something that can edge its way between the stuff and the parts, you might be able to peel it off. And if it's based on actual rubber try ozone to perish it fast so it will crumble away.

And what did you think the grey goop was made of? >:) Thpthpthp (That being my best Hannibal Lecter impersonation, feeble though it may be).

Lostgallifreyan wrote in news:Xns9C31E597F7238zoodlewurdle@216.196.109.145:

Likewise, strong shortwave UV might also help degrade it so it's easy to remove.

"William Sommerwerck" wrote in news:h1m3kv$pp3$ snipped-for-privacy@news.eternal-september.org:

I would but I don't think it will have me.

I've been using the mechanical approach. It is tedious and risky as you note. But does work:

However, some components were damaged (a graphics editing program can work wonders!) and for what I really want, it is trickier as the part being removed is a glass laser tube and much of the potting material is in a space 2 or 3 mm thick surrounding the tube, and running its entire length.

Thanks!

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De-Solv-It hardware stores Eposolve, mcmaster carr is your friend.

Steve

The best luck I've had is with simply picking the stuff off, you're right though that it's no fun. I suspect it would become brittle at some temperature, can you get your hands on some liquid nitrogen? If so, give it a soak and smack it with something, hoping the components within do not shatter as well. I'm curious to hear the results.

ncil

es,

asier

glue. =A0

The rubbery tarry stuff that is used in older hene tube heads dissolves in dichloromethane (DCM) used in paint strippers, The silicone stuff is pretty impervious to all but mechanical attack.

knives,

easier

sort of

surfaces,

What is the output level of the Cockcroft Walton circuit ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

FWIW There is a home decorating product called 'silicone eater' designed for removing sealant from hard surfaces by dissolving it a little.

--
Adrian C

That might work for the PCBs, though what will it do to the components?

However, what I really need to remove it from are special HeNe laser tube assemblies. Not the common laser heads, but ones where the tube is totally surrounded by the stuff as well as in front and back. So, the tube will still be stuck inside surrounded by brittle hard stuff. :)

Thanks for thinking about it!

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Greater than 10 kV but the current is very low since it only needs to drive an open circuit, then is bypassed once the main current flows. Nearly every HeNe laser power supply has a circuit like that.

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Whatever this stuf is, common sense suggests it was designed not to be easily removed, especially by chemical means. Otherwise, there would be little point to it.

Go to a good hardware store, and see if they have silicone tub caulk remover. Try that and see if it works.

I think that's only true in some cases. Since this CAN be removed using just brute force, it's a lot easier to reverse engineer PCBs and such with it than, say, hard Epoxy.

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Sam Goldwasser wrote in news: snipped-for-privacy@minus.seas.upenn.edu:

So do it the way a capacitor is removed from the PFN for the SSY-1. Use a fast cutting disk, or slow hacksaw, to cut the outer cylinder parallel to axis, peel it back enough to remove the innards, then peel the gunk off the internal cylinder (cap, or laser in this case).