What is this GOOP on circuit board?
Matt
Hi, readers.
I've noticed that guitar amp manufacturers often use rubbery GOOP that
looks like clear silicone(?) caulking to sort of glue down components
to circuit boards, presumably to dampen vibrations.
Is it worthwhile to use? If so, what is this goop, and where can I
get me some???
Thanks,
Donnie
It's hot glue....the new substitute to properly soldered connictions
Robert Fries
loco...@adan.kingston.net (Matt) wrote:
>Hi, readers.
>
>I've noticed that guitar amp manufacturers often use rubbery GOOP that
>looks like clear silicone(?) caulking to sort of glue down components
>to circuit boards, presumably to dampen vibrations.
>
>Is it worthwhile to use? If so, what is this goop, and where can I
>get me some???
>
>Thanks,
>
>Matt
>loco...@adan.kingston.net
It's clear silicone goop. Dampens vibrations, reduces strain on the leads and
solder joints.
RF
>
Robert Fries
rfries at netcom dot com
Greg J Szekeres
In article <6648jt$kdi$1...@gollum.kingston.net>,
Matt <loco...@adan.kingston.net> wrote:
>Hi, readers.
>
>I've noticed that guitar amp manufacturers often use rubbery GOOP that
>looks like clear silicone(?) caulking to sort of glue down components
>to circuit boards, presumably to dampen vibrations.
>
>Is it worthwhile to use? If so, what is this goop, and where can I
>get me some???
I know silicon is used and has been used, regardless of the type,
electronic grade or whatever. It withstands up to about 400 degrees.
It can be contaminated over time, absorbing things out of the air
and becomes a little less stiff. I have been trying out some
polyurethanes which seem stiffer than silicone rtv. There are alot of
other materials on the market, some harder to get in small quantities.
If you want to wet down an entire board, you might find some stuff
in a Newark catalog.
greg
Dave Hartzell
It's to mechanically secure the components so they won't break the
solder joints and cause them to have intermittant problems.
Matt wrote:
> Hi, readers.
>
> I've noticed that guitar amp manufacturers often use rubbery GOOP that
>
> looks like clear silicone(?) caulking to sort of glue down components
> to circuit boards, presumably to dampen vibrations.
>
> Is it worthwhile to use? If so, what is this goop, and where can I
> get me some???
>
> Thanks,
>
> Matt
> loco...@adan.kingston.net
Buffstereo
Hello! This is an interesting issue. I've located what appears to be silicone
sealent bonding caps and chokes to the crossover circuit boards in my 2 year
old Klipsch speakers. I have also found Silicone sealent useful for
household repairs and I think it ranks up there with duct tape in coolness.
However I have noticed when applying to bare iron bearing metal surfaces that
it immediately rusts the heck out of steel in particular. Since I use the clear
sealent , I can see the rust perfectly preserved under the transparent rubber
stuff. It wasn't rusty before I applied the goop. Now , I know some folks use
this stuff freely in audio but it has gotten me thinking that if this substance
can oxidize this metal so effectively then what will it do to anything else
within reach of the ambient out-gassing of this stuff as it dries and even
ages. What would happen within an enclosed chassis to electronic componets and
solder joints? The hot glue-gun technique is what I will do if I decide to go
this way at all. Thanks for the idea! From: buffs...@aol.com(Robert
Thompson)
Andrew Maxwell
It may be a conformal coating. Circuit boards tend to oxidise (copper
tracks going dark brown) when exposed to air, and this conformal coating
(which can either be thin or extremely thick) help prevent this as well
as provide protection against metal filings, etc,etc shorting the board
(much like a simple PCB coating), and prevent components from moving
due to knocks. It may also allow UV checking of hot spots, and prevent
variable components (varcaps, pots) from being tampered with.
PCB Conformal is available through Farnell, and RS, and many, many other
places.
I would use this if the boards you are making are critical to your setup
as it prevents any shorting, or component damage due to knocks, bumps,
drips, crunches, smashes, etc,etc..
Andrew
Donnie
sheeeeh....pardon my seemingly failed attempt at sarcasm
Matt wrote:
> Donnie <m...@myhouse.com> wrote:
>
> >It's hot glue....the new substitute to properly soldered connictions
>
> Hot glue? I've only limited experience with my glue gun, but usually
> the glue dries very hard. This GOOP is rubbery, and really does have
> the texture of removable-type caulking...ya know, like the kind one
> uses to stop drafts around windows, but you can pull off real easy?
>
> Like the texture of a gummy-bear.
>
> Matt
> loco...@adan.kingston.net
Matt
Anonymous
Robert Thompson raises the issue of corrosive outgassing during curing of
RTV silicone sealants.
There are two families of RTV sealants -- acid-curing ("good old RTV" --
smells like vinegar while curing) and alkaline-curing (originally marketed
by GE as "Silicone II" -- smells like ammonia while curing). When they
were first introduced, the alkaline-curing RTVs were decidedly inferior to
the acid-curing varieties in adhesion, cohesion, and life. Newer versions
appear to be much improved. The fine print on the package tells you which
kind it is. You can find both kinds at most home or building-supply stores.
The alkaline-curing RTVs are less corrosive as a class, and among them are
products specifically designed for outgas-sensitive applications like bare
metal and electronics. Loctite 5145 is one of these (GE, 3M, and Dow make
them too).
Loctite also makes "Tak Pak 444," a two-part instant-curing component
mounting adhesive.
Some of the neoprene-and-solvent cements are very sticky, very flexible,
and quite strong. They are really messy to use, though.
Where you need something REALLY tough, 3M 5200 Urethane adhesive (sold at
marine supply stores) is tops. Fully weather resistant, too. Unlike
epoxies, the quick set 5200 is nearly as good in most applications as the
slow-cure version.
John Kelley Brown
Matt wrote:
What you have there is most likely silicone.
Kelley
John Kelley Brown
patg...@hotmail.com wrote:
> Matt wrote:
> This GOOP is rubbery, and really does have
> > the texture of removable-type caulking...ya know, like the kind one
> > uses to stop drafts around windows, but you can pull off real easy?
> >
> > Like the texture of a gummy-bear.
>
> silcone sealant anyone ..
>
> and its still a substitute for a properly done assembly job
>
> pat
It really beats taking your time, placeing your components well and
securing them properly.
Kelley
HP Authorized Customer
Donnie <m...@myhouse.com> wrote in article
<663rqp$q...@bgtnsc03.worldnet.att.net>...
> It's hot glue....the new substitute to properly soldered connictions
>
> Matt wrote:
>
> > Hi, readers.
> >
> > I've noticed that guitar amp manufacturers often use rubbery GOOP that
> > looks like clear silicone(?) caulking
> >
> It is just silicone caulking, available at any local hardware store. It
is used to hold down capacitors mainly. Vibration is bad in any audio
signal path. It is also a good way to eliminate strain on the caps leads.
Kevin
kt...@cyberhighway.net
>
>
>
Dave Platt
>> > I've noticed that guitar amp manufacturers often use rubbery GOOP that
>> > looks like clear silicone(?) caulking
>
> It is just silicone caulking, available at any local hardware store.
Well... maybe.
Quite a few of the hardware-store silicone caulking materials release
acetic acid during the curing process. This isn't good, in an
electronic device, as the acid is somewhat corrosive to metal and can
lead to tarnishing and deterioration of PC-board traces, contacts, and
so forth.
There are other RTV silicone products which are sold specifically for
use in electronics applications - they do not release corrosive gasses
during the curing process. GE makes 'em (as do other manufacturers,
I'm sure), Newark carries 'em. They're significantly more expensive
than hardware-store silicones.
Some hardware-store RTV silicones (usually the more expensive types)
release ammonia rather than acetic acid. I don't know if this type
has corrosive effects on electronics or not.
Hot-melt glue is also used in many of these applications - it hardens
much faster than a silicone (but I imagine it's significantly more
expensive per application).
--
Dave Platt Speaker-to-kernels
dpl...@nc.com Network Computer Inc.
Visit the Jade Warrior home page: http://iq.nc.com/jade-warrior/
patg...@hotmail.com
Greg Szekeres
In article <667st4$ueb$1...@news.tvsoft.com>, dpl...@tvsoft.com says...
>
>>> > I've noticed that guitar amp manufacturers often use rubbery GOOP that
>>> > looks like clear silicone(?) caulking
>>
>> It is just silicone caulking, available at any local hardware store.
>
>Well... maybe.
>
>Quite a few of the hardware-store silicone caulking materials release
>acetic acid during the curing process. This isn't good, in an
>electronic device, as the acid is somewhat corrosive to metal and can
>lead to tarnishing and deterioration of PC-board traces, contacts, and
>so forth.
I,ve thought about this before. Most of the corosion occurs the first couple
of hours if ventillated. Any corosion will usually be visable if present.
It can harm certain things, sensors, etc. Newark used to sell Permatex
blue no leak gasket, which was sensor safe, or in other words electronic grade.
It is still available in stores and is alot cheaper than other electronic grade
silicon rtv's. Of course, its alot cheaper to buy the big gun tubes. Its
unfortunate that most of the gun tubes nowdays have no convenient way of capping
off, and the little tubes are hard to cap sucessfully. Sells more tubes,
ya know. Anyway, the conformal coatings come in different containers.
There is another liquid silicon called Sil-Guard. It has a long cure time
however, and is very runny and soft when curred. A real Gummy Bear.
greg
>
>There are other RTV silicone products which are sold specifically for
>use in electronics applications - they do not release corrosive gasses
>during the curing process. GE makes 'em (as do other manufacturers,
>I'm sure), Newark carries 'em. They're significantly more expensive
>than hardware-store silicones.
>
>Some hardware-store RTV silicones (usually the more expensive types)
>release ammonia rather than acetic acid. I don't know if this type
>has corrosive effects on electronics or not.
Well, I guess it should, being the opposite ph of an acid.
william bittle
Matt wrote:
>
> Hi, readers.
>
> I've noticed that guitar amp manufacturers often use rubbery GOOP that
> to circuit boards, presumably to dampen vibrations.
>
> Is it worthwhile to use? If so, what is this goop, and where can I
> get me some???
>
> Thanks,
>
> Matt
> loco...@adan.kingston.net
Yep, it is silicon rubber and it is used to keep the components from
vibrating and possibly working the foil loose on the PWB or breaking the
component leads loose. It is usually used on only the larger components,
but some manufacturrs seem to put a little blob on everhing. If you use
it, try not to get it on the wires, just use a little to help attach the
component to the PWB or chassis (depending on where it is mounted.) This
silicon is also used to, in some cases, actually mount parts to the
chassis, but it is kind of rinki-dink, and you would be better served
using a proper mounting clip.
B.B.
Rose Haupt
In article <6648jt$kdi$1...@gollum.kingston.net>, loco...@adan.kingston.net
says...
>
>Hi, readers.
>
>I've noticed that guitar amp manufacturers often use rubbery GOOP that
>looks like clear silicone(?) caulking to sort of glue down components
>to circuit boards, presumably to dampen vibrations.
>
>loco...@adan.kingston.net
>
I work as a electronics manufacturing engineer, and part of my job is to
do vibration qualification testing on various equipment. Large
componets, such as electrolitic capacitors, heat sinks on single
transistors, coils, etc, are prone to break with excessive vibration.
This can easily happen over time, with transportation (as in your van),
or if an amp head or similar (those vibes rock more than your booty).
The constant vibration can fatigue the metal leads until they crack and
eventually break.
Conformal coating (over the entire board) is seldom used, as, although it
has it's applications (such as corrosive atmospheres), it makes board
repair difficult. What you are looking at is probably plain old silicon
caulk. There are "special" formulations, but really little or no
difference from what you get at the hardware store. Hot melt is
sometimes used, but trickier to apply correctly, and may not adhear or
dampen as well.
Any component that you can move with moderate finger pressure could
probably benefit from some extra securing. If you subject the equipment
to vibration, it's probably cheap insurance. Don't get carried away - a
little dab between the component and the circuit board is fine, or
between adjacent componets so they support one another.
Tim Haupt
mind...@eskimo.com
William M. Johnson Jr.
John Kelley Brown wrote:
> It really beats taking your time, placeing your components well and
> securing them properly.
>
> Kelley
It sounds like one or another version of RTV, which, contrary to some
opinions, is not necessarily a bad thing. I spent some time with Collins
Avionics on their assembly line, and RTV is routinely used on larger
components such as capacitors to stabilize them when under vibration. It
has absolutely nothing to do with being a fix for poor soldering, quite the
contrary, it keeps the capacitors from moving in relation to the circuit
board under vibration, which flexes the leads otherwise and causes
premature component failure, in some cases the leads can literally break
and the component can fall off if the part isn't secured in this manner.
Then the plane falls out of the sky. Not good.
This RTV treatment also helps to reduce a component's tendency to pick up
microphonics, and is very commonly used on better quality equipment in most
types of electronics, from guitar amps to high end stereo equipment to the
most expensive types of test equipment.
C. Johnson
wjoh...@palmnet.net
Triode Electronics
"HP Authorized Customer" <kt...@cyberhighway.net> wrote:
>> It is just silicone caulking, available at any local hardware store. It
>is used to hold down capacitors mainly. Vibration is bad in any audio
>signal path. It is also a good way to eliminate strain on the caps leads.
Very good point. It may be necessary to pass UL testing.
IMA that copperweld capacitor leads exist for the same reason:
they pass the UL lead-bend test. Copperweld (or you may call
it copperclad) steel leads don't have a noticable advantage pricewise,
as far as the cap makers are concerned.
Ned Carlson, Triode Electronics, Chicago, IL http://www.triodeel.com
Open 12:30-8 PM CT, 12:30-5 PM CT Sat Closed Wed
ph:773-871-7459 fax 773-871-7938 "where da tubes are"
Email catalogs: email our CataBot: cat...@triodeel.com
Marty Kirkland
- snip
> This RTV treatment also helps to reduce a component's tendency to pick up
> microphonics, and is very commonly used on better quality equipment in most
> types of electronics, from guitar amps to high end stereo equipment to the
> most expensive types of test equipment.
>
> C. Johnson
> wjoh...@palmnet.net
Yes, but ...
I have repaired some television equipment where I was pretty certain
that the glue had broken down over the years and become somewhat
conductive. Removing the component, cleaning the board, and
reinstalling it has fixed more than one problem on mature equipment.
And yes, I have certainly seen the trace on the circuit board broken by
a large component vibrating around.
Marty Kirkland
Chief Engineer KUHT-TV
JohnG
> Avionics on their assembly line, and RTV is routinely used on larger
> components such as capacitors to stabilize them when under vibration.
Seems I've read somewhere that Klon and others use this goop to hide the
actual circuit from prying (and copying) eyes.
John
HP Authorized Customer
Rose Haupt <mind...@eskimo.com> wrote in article
<66aq4v$gq7$4...@eskinews.eskimo.com>...
> In article <6648jt$kdi$1...@gollum.kingston.net>, loco...@adan.kingston.net
> says...
> >
> >Hi, readers.
> >
> >I've noticed that guitar amp manufacturers often use rubbery GOOP that
> >looks like clear silicone(?) caulking to sort of glue down components
> >to circuit boards, presumably to dampen vibrations.
> >
> >Matt
> >loco...@adan.kingston.net
> >
>
>
> eventually break.
> Its also a great, cheap way to "glue" down components when some type of
bracket would be awkward or "expensive" to use. manufacturers look at the
bottom line if they want to survive, they usually disregard the latest
"tweaks".
How many amps have you seen with exotic bypass caps, silver or copper/oil
coupling caps, graphite filter caps, high priced resistors, hand soldered
ladder attenuators,... Hey, silicone fits the bill just fine to keep those
computer grade caps in their place, and the bay watch babes in spending
money.
>
Lord Valve
It's bird poo. Don't mess with it.
LV