Cho-Bond ONE Component Moisture Cure
Electrically
Conductive RTV Adhesives and Sealants
FREQUENTLY
ASKED QUESTIONS
01.
What are Chomerics Cho-Bond (pronounced “ko-bond”) RTV products?
Top
Chomerics
provides electrically conductive, room temperature vulcanizing
(RTV), moisture cured silicone adhesives and sealants.
All of our RTV systems are silicone based and vary
by having different types of conductive filler.
Due to the filler loading differences, each material
has different mechanical properties.
Please see the specific data sheets for details.
This family includes Cho-Bond 1030, 1035, 1038 and 1075. [Cho-Bond 1029 is a two component system and
is not part of the moisture cure RTV family.
This is a link to a product summary showing the typical
properties of these materials:
http://www.chomerics.com/products/documents/Compoundssel_guide.pdf
02.
Where can I find technical data sheets and MSDS information?
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You
can find all of our technical data sheets, MSDS’ and other
literature on our web site at:
Product
Literature Library
03.
What is supplied in a kit of Cho-Bond RTV material?
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Cho-Bond
RTV material is typically supplied in two sizes, a smaller
foil tube version (2.5 ounce or 4.0 ounce by weight) and
a larger caulking cartridge version (10 ounce or 1 pound
by weight). [Note: The MSDS for the Cho-Bond and the Primer 1086
are included in each shipment.]
The smaller version comes with a key to help squeeze out
the material, a plastic nozzle and a 3 dram vial of our
silicone Primer 1086.
The larger version comes vacuum-sealed in a foil-lined bag
with a desiccant, a 4 inch long by .093” diameter nozzle
and a 3 dram vial of our silicone Primer 1086.
04.
What is the shelf life of Cho-Bond RTV material?
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Cho-Bond
RTV has a shelf life of 6 months from the date of manufacture. It will have 80% minimum shelf life remaining
when purchased directly from Chomerics.
Material bought through our distribution network usually
has a –55 suffix on it, which means that product has a shelf
life of 9 months from date of manufacture at Chomerics.
You will need to speak with your specific distributor
to determine the amount of shelf life remaining on his stocked
material.
05.
Is there Shelf Life extension available for Cho-Bond silicone
RTV?
Top
YES
– under the following conditions.
1.
There is a fee of $250 per lot to be tested. This fee applies regardless of whether the material
passes or fails.
2.
A single kit of material from each lot is sent back to Chomerics
for testing and these kits are retained by Chomerics for
our QC record purposes.
3.
This process takes typically one business week once the material
is received at Chomerics.
4.
The shelf life extension will be for a ½ the original shelf
life of the material, which in the case of Cho-Bond silicone
RTV is and additional 3 months.
06.
Can I speed up the cure time of Cho-Bond RTV?
Top
NO – this material
cures on exposure to atmospheric moisture. It cures best at room temperature and 50% relative
humidity. The material
cures from the outside in, so it may appear cured, but may
still be uncured beneath the surface of the bond.
Uncured material will not exhibit the mechanical
and electrical properties that we specify on our data sheet.
However, it is common place for customers to determine
how much cure time is actually necessary for their specific
application. Some customers have found 24, 36 or 48 hours
works for them in their particular application.
The end user is responsible for any failures which
occur when not allowing the full 7-day cure.
Note that as long as the material continues to be exposed
to the atmosphere, it will continue to cure.
So, for example, if 48 hours has been determined
to be sufficient for a particular application, as long at
the material continued to be exposed to the atmosphere,
if it were still uncured, it would continue to cure.
Sealing the Cho-Bond material in a bag would cut
off atmospheric moisture, and may never allow for full cure.
07.
What do I do with the Chomerics Primer 1086?
Top
Primer
1086 is a silicone primer used to enhance the bond between
a metal surface and the silicone Cho-Bond material.
THE PRIMER IS NOT MIXED WITH THE CONDUCTIVE
RTV. THE ADHESIVE
IS A SINGLE COMPONENT SYSTEM AND CURES WHEN EXPOSED TO THE
ATMOSPHERE. The primer
does not need to be applied to an elastomer gasket, only
to metal surface(s) that needs to contact the Cho-Bond.
Chomerics strongly recommends that you use the Primer
1086 so that a strong bond is attained.
To apply Primer 1086, thoroughly clean
and degrease the surface to be primed.
Solvents such as Isopropyl Alcohol (IPA), Toluene,
Methyl-Ethyl-Ketone (MEK) and Acetone are typical cleaning
/ degreasing solvents. Allow
the solvent to flash off the metal surface, then
apply a coat of Primer 1086 by wiping a thin film onto the
metal surface. Use adequate ventilation. A typical applicator is a cotton swab or clean
lint free rag. Allow
the primer to dry/cure from 30 to 60 minutes.
(The primer is also a moisture cure system).
Next apply the Cho-Bond material.
Please note that a primed surface that is not bonded
within 4 hours should be re-cleaned and re-primed as the
original primed surface will no longer function properly.
Technical
Bulletin 33 is very helpful in listing surface
preparation for various substrates.
08.
Can I break the joint bonded or sealed with Cho-Bond silicone
RTV?
Top
YES
– with some effort. As
a silicone based system, the Cho-Bond will soften and swell
when exposed to certain solvents, in particular Toluene.
Methyl-Ethyl-Ketone and Acetone will also work to
a lesser degree. In
a well ventilated area, using a wooden tongue depressor
or similar non-metal tool, apply the solvent to the joint
and then work the joint removing the cured Cho-Bond.
Re-apply the solvent as more Cho-Bond is removed
until the joint can be broken. Continue to repeat this process until all of
the Cho-Bond is removed.
09. What is the
minimum buy requirement for Cho-Bond silicone RTVs?
Top
Each
material has its own minimum buy requirement direct from
Chomerics. Please Contact Us and speak with a Chomerics
Inside Sales
Representative to get the details.
10. What is the
typical lead time for Cho-Bond silicone RTVs?
Top
The
typical lead time for these materials is 3 weeks. Chomerics does not typically stock this material
due to shelf life concerns.
11. Can I buy
Cho-Bond silicone RTVs through Chomerics Distribution network?
Top
YES – Chomerics has a list of distributors that may be stocking
this material for immediate sale.
In most cases, the minimum buy requirement from a
distributor will be less than Chomerics as well.
Chomerics recommended STOCKING distributor for
Cho-Bond silicone RTVs is Marketing East (978) 921-9299.
