RTV Silicone And Coax Outer Jacket: Safe ?
 

Hello:

Is it safe to use the typical GE RTV silicones against a Polyethylene (PE)
coax outer jacket ?

I know the RTV's use some type of acid (acetic ?) to cure the stuff, and I
was wondering if
anyone might have any first hand experience if there is any kind of
interaction with a coax outer jacket ?

Thanks,
Bob

RTV Silicone And Coax Outer Jacket: Safe ?
 

Bob,

Go to h

http://www.dowcorning.com/content/et..._aas_1ptov.asp

for just about everything you would ever want to know. We use several
grades of electronics RTVs at work in contact with coaxial cable jackets
and all kinds of components to meet DO-160E vibration requirements for
airplave use. The stuff we use does not have the characteristic acetic
acid smell which I think is actually stearic acid.

73,
Larry, W0QE


Robert11 wrote:
Hello:

Is it safe to use the typical GE RTV silicones against a Polyethylene (PE)
coax outer jacket ?

I know the RTV's use some type of acid (acetic ?) to cure the stuff, and I
was wondering if
anyone might have any first hand experience if there is any kind of
interaction with a coax outer jacket ?

Thanks,
Bob

RTV Silicone And Coax Outer Jacket: Safe ?
 

In article ,
Larry Benko wrote:

Bob,

Go to h

http://www.dowcorning.com/content/et..._aas_1ptov.asp

for just about everything you would ever want to know. We use several
grades of electronics RTVs at work in contact with coaxial cable jackets
and all kinds of components to meet DO-160E vibration requirements for
airplave use. The stuff we use does not have the characteristic acetic
acid smell which I think is actually stearic acid.

According to the labels I've read, much of the consumer-grade RTV does
in fact release acetic acid as it cures. Not good stuff to use around
electronics or other metals.

The noncorrosive, "moisture cure" or "neutral cure" RTVs are a better
choice for use around electronics. The ones marketed as "electronics-
grade" are the surest bet in this regard, and usually need to be
mail-ordered. A possible compromise would be the consumer-grade RTVs
which are specifically advertised as being noncorrosive for use on
metals - the labels on these say that they release methanol and
ammonia during cure.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

RTV Silicone And Coax Outer Jacket: Safe ?
 

ORIGINAL MESSAGE:

Dave Platt wrote:


The noncorrosive, "moisture cure" or "neutral cure" RTVs are a better
choice for use around electronics. The ones marketed as "electronics-
grade" are the surest bet in this regard, and usually need to be
mail-ordered.



*********** REPLY SEPARATOR ***********

Your local pet shop will have RTV made for sealing glass aquariums
which does not release acetic acid or anything else harmful to fish. If
it won't harm fish, it surely won't harm your hardware.

73, Bill W6WRT

RTV Silicone And Coax Outer Jacket: Safe ?
 

On Mon, 13 Mar 2006 18:59:34 -0500, "Robert11" sent
into the ether:

Hello:

Is it safe to use the typical GE RTV silicones against a Polyethylene (PE)
coax outer jacket ?

I know the RTV's use some type of acid (acetic ?) to cure the stuff, and I
was wondering if
anyone might have any first hand experience if there is any kind of
interaction with a coax outer jacket ?

Thanks,
Bob



Bob,
I have been using GE 1200 on coax and connectors since the early
seventies and have never had a problem with it affecting good silver
plated or cheap connectors or the varying grades of coax I have used.
If you want to be fussy cover the connector with electrical tape and
then cover with silicone. This makes it easier to remove but is not
necessary for protecting the connector or the coax. I would not use
it inside of a radio or other electronic equipment but outside of that
it will not hurt and will keep the connection free of moisture, BTW,
if you do wrap it with tape first be sure to coat the coax past the
tape to ensure a good waterproof seal.

N9JBF



I've learned that I don't suffer from insanity, I enjoy it!

Remove the x for e-mail reply
www.outdoorfrontiers.com
www.SecretWeaponLures.com
A proud charter member of "PETAF", People for Eating Tasty Animals and Fish!!!

RTV Silicone And Coax Outer Jacket: Safe ?
 

The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)

I've used the acetic-acid smelling stuff for decades on a variety of
metals including tinned and untinned wire, aluminum, nickel, and copper
circuit boards, and never seen a hint of corrosion. But formulations
vary widely, and my experience certainly isn't exhaustive. I'm not
entirely convinced, though, that among the many formulations there
aren't others, which don't have that smell, which might be corrosive to
some materials.

People who worry about this should buy an industrial product and stay
with it, since there's a much better chance the formulation won't change
in the future without notice.

Roy Lewallen, W7EL

RTV Silicone And Coax Outer Jacket: Safe ?
 

On Mon, 13 Mar 2006 23:14:29 -0800, Roy Lewallen
wrote:

The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)

[snip]

Roy Lewallen, W7EL

HI Roy,

I have been using a different product for over a decade that works
great - liquid vinyl tape. It does a heck of a job for sealing
water-tight connections and, like RTV, doesn'g get hard and crack.
You can buy it a most hardware stores.

Its easy to use and, like was suggest earlier in this thread, I first
wrap the connection with regular vinyl tape (a single layer) before
appling the liquid compond - its makes for much easier removal when
needed.

73
Danny

RTV Silicone And Coax Outer Jacket: Safe ?
 

I was visiting a local SGC dealer years ago as he was troubleshooting a
brand new antenna tuner that was not working. When he opened the plastic
case, that special RTV acidic smell almost knocked us over and all the
tinned circuit board traces and exposed wiring were corroded and black.
SGC claimed they used the wrong type of RTV on a batch of tuners that
was not for electronics use.
Mike


Roy Lewallen wrote:
The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)

I've used the acetic-acid smelling stuff for decades on a variety of
metals including tinned and untinned wire, aluminum, nickel, and copper
circuit boards, and never seen a hint of corrosion. But formulations
vary widely, and my experience certainly isn't exhaustive. I'm not
entirely convinced, though, that among the many formulations there
aren't others, which don't have that smell, which might be corrosive to
some materials.

People who worry about this should buy an industrial product and stay
with it, since there's a much better chance the formulation won't change
in the future without notice.

Roy Lewallen, W7EL

RTV Silicone And Coax Outer Jacket: Safe ?
 

Mike wrote:
Roy Lewallen wrote:
The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)
I've used the acetic-acid smelling stuff for decades on a variety of
metals including tinned and untinned wire, aluminum, nickel, and
copper circuit boards, and never seen a hint of corrosion. But
formulations vary widely, and my experience certainly isn't
exhaustive. I'm not entirely convinced, though, that among the many
formulations there aren't others, which don't have that smell, which
might be corrosive to some materials.
People who worry about this should buy an industrial product and
stay with it, since there's a much better chance the formulation
won't change in the future without notice.
Roy Lewallen, W7EL

I was visiting a local SGC dealer years ago as he was troubleshooting a
brand new antenna tuner that was not working. When he opened the
plastic case, that special RTV acidic smell almost knocked us over and
all the tinned circuit board traces and exposed wiring were corroded
and black. SGC claimed they used the wrong type of RTV on a batch of
tuners that was not for electronics use.

Most likely because they closed the cases before the silicone had cured,
not realising they were trapping the acetic acid vapour inside. The same
can happen in balun boxes and the like.

It would be interesting to know if there have been *any* cases that
didn't also involve some kind of closed situation, or possibly a layer
that was too thick to let the vapour diffuse out.



--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

RTV Silicone And Coax Outer Jacket: Safe ?
 

Dan Richardson k6mheatadelphia wrote:
On Mon, 13 Mar 2006 23:14:29 -0800, Roy Lewallen
wrote:

The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)

[snip]
Roy Lewallen, W7EL

HI Roy,

I have been using a different product for over a decade that works
great - liquid vinyl tape. It does a heck of a job for sealing
water-tight connections and, like RTV, doesn'g get hard and crack.
You can buy it a most hardware stores.

Its easy to use and, like was suggest earlier in this thread, I first
wrap the connection with regular vinyl tape (a single layer) before
appling the liquid compond - its makes for much easier removal when
needed.

I've pretty much switched completely to the Plasti-Dip stuff myself. It
is readily available in at least two colors--red and black--at Lowe's.

I used RTV, both the acetic acid and non-acetic acid varieties through
the years. After a couple of unpleasant corrosion experiences with the
acetic acid type, I began either wrapping connectors with vinyl
electrical tape or spraying with acrylic sealant and then applied the
RTV. Either way works well. I recall seeing cautions that one should
be wary of black RTV in that it could conduct. I don't know whether it
can break down but I've used the clear product.

Dave Heil K8MN

RTV Silicone And Coax Outer Jacket: Safe ?
 

On Mon, 13 Mar 2006 23:14:29 -0800, Roy Lewallen
wrote:

The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)

OK, here is number 2. Hmmm wait... couldn't we use a different
ranking...

I retired from the industry and I worked for the original developer of
"Silastic RTV (TM)". My address if Midland MI if any one needs another
hint.

Yes there is an weak acid released from the regular RTVs and it
depends on the moisture in the air to aid in curing.

Is it, or will it be a problem? That is a Yes and no, or it all
depends answer.
I use plain old fashion "bathtub calk" on my antenna connections and
connectors *outside or outdoors*

The acid is not normally a problem *except* where the item is either
potted, or enclosed in a container. I would not use it on PC boards
where the foil is thin.

Outdoors I just "gob it on".

As to real corrosion:
Some years back we purchased a bunch of remote sensors that were
potted in metal boxes for use in harsh environments. They worked very
well... for about a year. One failed and who ever removed it brought
it into the shop. I decided to perform an autopsy on it. I cut the
seal, pried off the cover, and dug out the circuit board, or rather
what was left of it. The copper traces were mainly a green powder
with bigger chunks of powder around the solder joints where the wires
hung loosely.

The manufacturer of the sensors had used the wrong potting compound.
Had they used the neutral stuff (really stinks) they would have been
fine. They replace them all, they were expensive, and we had a bunch.


I've used the acetic-acid smelling stuff for decades on a variety of
metals including tinned and untinned wire, aluminum, nickel, and copper
circuit boards, and never seen a hint of corrosion. But formulations
vary widely, and my experience certainly isn't exhaustive. I'm not

There are two main producers of RTVs and the formulations are pretty
much standard. If you analyzed a tube of the stuff I doubt you could
tell which manufacturer produced it. However they have slightly
different formulations aimed at the specific use. What every you
purchase under what ever brand name most likely comes from one of
these two producers unless it says Made in China.


entirely convinced, though, that among the many formulations there
aren't others, which don't have that smell, which might be corrosive to
some materials.


People who worry about this should buy an industrial product and stay
with it, since there's a much better chance the formulation won't change
in the future without notice.

The last I knew the only difference was in the packaging.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roy Lewallen, W7EL

RTV Silicone And Coax Outer Jacket: Safe ?
 

On Tue, 14 Mar 2006 19:04:48 +0000, Ian White GM3SEK
wrote:

Mike wrote:
Roy Lewallen wrote:
The advice to avoid acetic-acid smelling RTV because of corrosion is
passed along from person to person like an urban legend, but like an
urban legend it's just about impossible to find anyone who's actually
seen any corrosion result from its use. (A number of queries I've made
over the years has produced just one, using a very early version of RTV.)
I've used the acetic-acid smelling stuff for decades on a variety of
metals including tinned and untinned wire, aluminum, nickel, and
copper circuit boards, and never seen a hint of corrosion. But
formulations vary widely, and my experience certainly isn't
exhaustive. I'm not entirely convinced, though, that among the many
formulations there aren't others, which don't have that smell, which
might be corrosive to some materials.
People who worry about this should buy an industrial product and
stay with it, since there's a much better chance the formulation
won't change in the future without notice.
Roy Lewallen, W7EL

I was visiting a local SGC dealer years ago as he was troubleshooting a
brand new antenna tuner that was not working. When he opened the
plastic case, that special RTV acidic smell almost knocked us over and
all the tinned circuit board traces and exposed wiring were corroded
and black. SGC claimed they used the wrong type of RTV on a batch of
tuners that was not for electronics use.

Most likely because they closed the cases before the silicone had cured,

That outgasing from a think layer will go on for many days which would
make it impractical to use in this case.

not realising they were trapping the acetic acid vapour inside. The same
can happen in balun boxes and the like.

In this case it would also depend on how much RTV, or how thick the
layer of RTV. As I said, the outgasing will go on for quite some time
and the thicker the longer it outgases. I'd not use the acid smelling
version from either producer on PC boards.

It would be interesting to know if there have been *any* cases that
didn't also involve some kind of closed situation, or possibly a layer
that was too thick to let the vapour diffuse out.

A thin layer should cause no problem if it is given time to outgas,
but a thick layer will most likely eventually ruin the PC board.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

RTV Silicone And Coax Outer Jacket: Safe ?
 

Roger wrote:
I was visiting a local SGC dealer years ago as he was troubleshooting a
brand new antenna tuner that was not working. When he opened the
plastic case, that special RTV acidic smell almost knocked us over and
all the tinned circuit board traces and exposed wiring were corroded
and black. SGC claimed they used the wrong type of RTV on a batch of
tuners that was not for electronics use.

Most likely because they closed the cases before the silicone had cured,

That outgasing from a think layer will go on for many days which would
make it impractical to use in this case.

not realising they were trapping the acetic acid vapour inside. The same
can happen in balun boxes and the like.

In this case it would also depend on how much RTV, or how thick the
layer of RTV. As I said, the outgasing will go on for quite some time
and the thicker the longer it outgases. I'd not use the acid smelling
version from either producer on PC boards.

It would be interesting to know if there have been *any* cases that
didn't also involve some kind of closed situation, or possibly a layer
that was too thick to let the vapour diffuse out.

A thin layer should cause no problem if it is given time to outgas,
but a thick layer will most likely eventually ruin the PC board.

Agreed; but that isn't really the fault of the silicone material. It's
more like "misuse".

But why do we use silicone for coax/antenna sealing anyway? Anything for
which you might use silicone could probably be done a lot better using
hot-melt glue.

Ordinary hot-melt glue (amorphous polypropylene) has good RF properties,
is non-corrosive, is very sticky, seals very well to metals and
plastics, is flexible, has no problems about being used in thick layers,
sets in minutes rather than hours, has at least as good weathering
properties as silicone, can be removed by cutting, peeling or melting,
and is very economical.

You can often use it in the backyard without electrical power, because a
typical glue gun gives up to 5 minutes working time after having been
unplugged.

There's more information in the archives of this group, thanks to Barry
Ornitz, WA4VZQ.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

RTV Silicone And Coax Outer Jacket: Safe ?
 

On Mon, 13 Mar 2006 18:59:34 -0500, "Robert11"
wrote:

Hello:

Is it safe to use the typical GE RTV silicones against a Polyethylene (PE)
coax outer jacket ?

I know the RTV's use some type of acid (acetic ?) to cure the stuff, and I
was wondering if
anyone might have any first hand experience if there is any kind of
interaction with a coax outer jacket ?

Thanks,
Bob

Although Bob isn't asking about sealing connectors, this thread has
drifted that way.

If this is indeed his need, then I offer my method. I use
Plymouth-Bishop No. 122 rubber tape followed by an overwrap of a good
quality vinyl tape.

http://www.plymouthbishop.com/

If memory serves, I bought the 122 at Home Depot, although their web
site doesn't show that they carry it anymore. An electrical supply
house would likely be a source.

RTV Silicone And Coax Outer Jacket: Safe ?
 

Scotch® Self-Fusing Silicone Rubber Electrical Tape 70
1 in x 30 ft

This is a high-temperature, arc-and track-resistant tape composed of
self-fusing, inorganic silicone rubber with an easy-tear and easy-strip liner.
Packed 1 per box, 10 per carton with 50 per case.

RTV Silicone And Coax Outer Jacket: Safe ?
 

In article ,
Wes Stewart wrote:

If this is indeed his need, then I offer my method. I use
Plymouth-Bishop No. 122 rubber tape followed by an overwrap of a good
quality vinyl tape.

http://www.plymouthbishop.com/

If memory serves, I bought the 122 at Home Depot, although their web
site doesn't show that they carry it anymore. An electrical supply
house would likely be a source.

My local Home Depot had it in stock as of last week... I bought a
couple of rolls, and they had plenty more.

Their web site seems to show only a fraction of what they have in the
stores.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!