
To further assist Nox-Crete customers and distributors find solutions to their concrete problems, we have
compiled the following Frequently Asked Questions section. Just click on your area of interest and select the
question most relevevant to your needs. If you find you need further technical assistance than is provided
here, please use the Contact Us link for information on how to reach our corporate office or one of our
knowledgeable staff.
For specific information regarding application and usage, always read the full Product Data Sheet and
Material Safety Data Sheet (MSDS) for the product you are applying.
Concrete Cleaners And Strippers
Q: How do I remove tile adhesive?
What product and procedure do you recommend for removing vinyl tile adhesive
residue from a concrete floor surface?
| | A: The best product to remove vinyl tile adhesive residue
is Nox-Crete’s Bio-Clean.
Bio-Clean contains a strong biodegradable solvent that can be diluted with up to
two parts water. Apply Bio-Clean with a mop or roller to the floor.
Allow Bio-Clean to sit for 15-20 minutes to soften and dissolve the tile adhesive residue.
Scrub the floor using a scrubbing machine equipped with a nylon bristled scrub brush until
the adhesive has been removed. Rinse the floor well with with water. The water and residue
can then be either squeegee into a floor drain or vacuumed up using a wet/dry vacuum.
The residue is biodegradable and should be able to be disposed of through any municipal
sanitary sewer system.
|
Q: How do I remove an acrylic cure and seal?
An acrylic cure and seal product was previously
applied to our warehouse floor. We would like to apply Duro-Nox liquid
floor hardener and dustproofer to the floor. How can we cost effectively
remove the sealer?
| | A: Depending upon the type
of acrylic cure and seal used, you may be able to use
Bio-Clean to remove the
coating. Tougher acrylics containing more acrylic and less hydrocarbon resins
may require the use of Bio-Strip.
Perform a test application to determine which product and dilution rate
works best in your application.
|
Q: What’s the best
product for floor prep
cleaning prior to acid staining?
We have a floor that we would like to acid stain with
Nox-Crete’s Varichrome acid stain. The floor currently has some oil
and grease residue. Do these need to be removed first and, if so, what do you recommend?
| | A:
Bio-Clean is extremely effective at
removing oil and grease residue from concrete floor surfaces. Depending
upon the severity of the contamination, Bio-Clean may be diluted with water to reduce cost.
Perform a test
application to determine the proper dilution ratio.
|
Q: What’s the best way to remove black
tire marks and oil spots from a concrete floor?
The operation of rubber tired construction equipment has
left small oil spots and rubber tire marks on the new floor of a
warehouse distributor center our company recently constructed. The owner
is insisting that we remove all oil spots and
rubber tire marks from the floor surface. Any suggestions?
| | A: Nox-Crete’s
Bio-Clean is
the ideal product for removing these types of stains from concrete floor surfaces.
Rubber tire marks and minor oil and grease stains are easily
removed by diluting Bio-Clean with two parts water
and running it through an automatic floor scrubbing machine.
Tough oil and grease spots can be pretreated by
spraying the diluted Bio-Clean on the spot prior to machine
cleaning with the automatic floor scrubber. |
Cures, Sealers and Hardeners
Q: How do we get gloss faster with a silicate hardened concrete floor?
We have applied a silicate based liquid floor hardener and
dustproofer to our concrete warehouse floor. We understand
that through use and over time the floor will become glossier. Is there any thing we can do now to
improve the shine of
our newly treated floor?
| | A: To achieve an immediate high gloss
finish to a silicate treated concrete floor, apply
Duro-Polish. Floors
recently treated with silicate type liquid hardener and dustproofers typically provide gloss
readings in the range of
15 to 25 gloss units when tested with a Horiba IG-320 meter measured at a 60 degree angle.
The same floors,
after treating with Duro-Polish, typically exhibit gloss unit readings in
the range of 35 to 50.
|
Q: What is the difference between Duro-Polish and Duro-Polish Plus?
| | A: Both products offer
the same benefits of gloss and slip-resistance. However,
Duro-Polish Plus
also contains a
halogenated silicon containing additive that provides stain repellency from both
inorganic and organic containing
materials. In other words, Duro-Polish Plus provides stain repellency from
common stain-causing agents such as
soft drinks, coffee and tea, as well as oil and grease.
|
Q: What product
should be used to seal colored stamped concrete?
| |
A: For protection and a
high gloss, “wet look” finish that enhances the color of stamped concrete, use Nox-
Crete’s
Sparkl-Seal VOC & LVOC. Sparkl-Seal VOC & LVOC are high solids, non-yellowing, methyl methacrylate acrylic sealers that resist surface oxidation from the sun and chemical pollutants in the air. In addition, Sparkl-Seal VOC & LVOC has
good water vapor permeability properties which allow the coating to breath,
reducing the risk for surface
delamination or blistering.
|
Q: Why does a
clear sealer turn white?
The clear sealer we have been applying to stamped
concrete occasionally turns frosty white in color. What causes this
and how do we prevent it? How do we remove the existing clear sealer?
| |
A: A clear sealer which turns
frosty white in color has delaminated from the concrete
surface. This is most likely
due to the coating’s inability to release water vapor trapped
within the concrete quickly enough to prevent
pressure buildup beneath the coating. To prevent this problem,
use a clear acrylic sealer offering improved water
vapor permeability. We recommend
Sparkl-Seal VOC & LVOC
or water based
Sparkl-Seal E
in exterior coating applications that are subject to high
moisture content. To remove the existing delaminated coating, use Nox-Crete’s
Bio-Strip.
Bio-Strip can be
diluted with one or two parts water. A test should be done to
determine the optimum dilution rate. Apply Bio-Strip
to the area requiring coating removal using a mop or roller. Allow
Bio-Strip to penetrate and soften the acrylic
coating for 15-20 minutes and then scrub the surface with a floor
polishing machine equipped with a stiff bristle
nylon scrub brush to remove the coating. Rinse the surface with water to
remove the residual Bio-Strip and
acrylic coating. Allow the surface to dry for a minimum of 48 hours before
applying a clear sealer.
|
Q: Can Duro-Polish be used over acrylic sealers?
| | A:
Duro-Polish is ideally suited
for use over acrylic sealers used in interior applications, such as over acidstained
concrete floors, and will increase the gloss and slip resistance of these
interior concrete floor surfaces.
|
Q: How durable
is the finish provided by Duro-Polish?
I like the idea
of the increased gloss possible with Duro-Polish. However,
I am concerned about the longevity and
possible peeling or flaking problems resulting from the
use of this type of product.
| | A:
Duro-Polish
is a unique product that is not prone to
typical problems associated with the use of traditional
polishes. Duro-Polish will provide 3-5 years or more of
service life in relatively high use areas such as retail
environments. As the aggregate peaks of the floor surface
become polished through use and take on their own
gloss, the need for Duro-Polish is reduced. Duro-Polish has
a very low molecular weight which enables it to
penetrate concrete surfaces. As a result, when properly applied,
Duro-Polish is “in” the concrete more than it is
“on” the concrete. Because of this, Duro-Polish will never
peel or flake off of a treated concrete surface.
|
Q: What
options are available for low odor, indoor sealer applications?
We would like
to apply a clear acrylic sealer over colored concrete in an interior application.
The owners cannot tolerate
any solvent odor. Please provide a product recommendation.
| | A: We recommend the application of
Sparkl-Seal E.
Sparkl-Seal E is a transparent, water based, methyl
methacrylate acrylic sealer. It has essentially no odor and the
water based formulation means it can safely be
used in an occupied interior application. For more gloss and
additional slip resistance, apply a final finish of
Duro-Polish.
|
Q: What’s the
best choice for hardening and sealing a concrete floor?
Please provide
your best product recommendation for sealing, hardening and
dustproofing a warehouse floor. Are any
product warranties available?
| | A: The application of
Duro-Nox,
a reactive, silicate type, liquid floor hardener and sealer is
ideal for this usage.
Duro-Nox chemically reacts with calcium hydroxide within concrete to form silicate
gels on the surface which
densify, harden and seal concrete to the depth of penetration. Nox-Crete offers a
20-year performance warranty
on eligible Duro-Nox applications. |
Form Release Agents
Q: Form oil costs have nearly tripled over the last four years. Is there a less expensive option to consider?
| | A: Yes. With the rising costs
of petroleum, traditional petroleum based form release agents have become
increasingly more costly. Water based form release agents replace expensive
petroleum solvents with up to 88%
water. In addition, water based form release agents perform
as well or better than traditional petroleum based
products, are safer for workers and the environment, and cost
substantially less.
|
Q: What is the difference between a chemically reactive form release agent and a barrier type release agent?
What product and procedure do you recommend for removing vinyl tile adhesive
residue from a concrete floor surface?
| | A: Barrier type form release agents,
also known as form oils, use heavy oils diluted in lighter oil such as
kerosene oil or diesel fuel. When applied to a form surface, the lighter oil
is designed to evaporate, or flash off,
leaving a film of the heavier oil on the form surface. The heavy oil acts
as a barrier, much the same as grease on
a cookie sheet, to prevent concrete from sticking to form surfaces.
Obvious problems with barrier type form
release agents include the oil migrating vertically during the
vibrating process, which results in form sticking, as
well as unsightly oil stains on the cast concrete surface.
A chemically active form release agent contains an
active ingredient that combines with the calcium hydroxide (lime)
in fresh concrete to form a metallic, waterproof
soap which prevents concrete adhesion to treated surfaces.
Resulting concrete is uniformly bright white in color
and free of surface discoloration. Chemically active form
release agents are also typically reactive with wood and
steel form surfaces, which prevents their migration before
or during concrete placement.
|
Q: Why are
Nox-Crete form release agents considered "good for the wood"?
| | A: The highly alkaline bleed water in
fresh concrete penetrates plywood form surfaces and removes the natural
fats and oils from within the wood. Because these fats and oils
keep the wood fibers pliable, their removal causes
wood fibers to split and crack. Nox-Crete’s chemically
active form release agents replace the natural fatty acids
lost to the concrete and also form metallic waterproof
soaps on the form surface to help minimize the penetration
of the alkaline bleed water. Regular use of Nox-Crete
form release agents on wood forms is like using hand lotion
on dry, chapped hands - the more frequently it is used,
the fewer splits and cracks you will have and the longer
your forms will last.
|
Q: How many extra
pours can I expect from my forms if I use a Nox-Crete form release agent?
| | A: Depending upon
the conditions specific to your application, you can expect up
to a 20% increase in form life
by using a Nox-Crete form release agent compared to a
traditional form oil.
|
Q: Does
Nox-Crete manufacture a form release agent that is not as slippery?
My
company constructs elevated concrete decks using crane set overlaid plywood
flying forms. Once the form release
has been applied the deck surface becomes slippery causing
an unsafe condition for our workers. We need a safer
solution.
| | A: Both
Nox-Crete PCE
and
Nox-Crete PCS
dry to form a wax-like film on treated form surfaces which is
considered to be fairly slip resistant. Both products
are designed to be applied to non-absorptive form surfaces
such as phenolic surface film (PSF) or high density
overlaid (HDO) plywood forms. PCE is water based and PCS
is petroleum solvent based.
|
Q: Does Nox-Crete offer
biodegradable form release agents?
We are
working for an owner who has asked us to use a biodegradable
form release agent. We are using a combination
of a steel-framed handset forms and loose panel plywood forms. Any suggestions?
| | A: A new
version of the original
Nox-Crete Form Coating,
called
Nox-Crete Form Coating EB,
has recently been
introduced that meets the EPA definition for “Ready Biodegradability.”
Nox-Crete Form Coating EB is water
based and is ideal for use on steel-framed handset forms
and loose panel plywood forms.
|
Q: Are
water based form release agents really “as good or better” than the petroleum based alternatives?
| | A: Yes. All Nox-Crete
water based form release agents are just as good or better
than their petroleum solvent
based counter parts. In addition, the water based products are
less expensive.
|
Q: How can I
ensure proper mixing of water based form release agents?
I am
considering trying a super concentrated, water based form release agent,
but I am concerned about mixing. How
can I ensure that my workers will properly dilute and mix the product?
| | A: All Nox-Crete
super concentrated form release agents require careful
attention to dilution to ensure maximum
product performance. Fortunately, we have developed the
easy-to-use
Mix Station
which simultaneously dilutes
and mixes. The Mix Station rests on top of a 55 gallon
drum or 275 gallon tote. A water hose is attached to the
Mix Station. By opening the mix valve, the super concentrated
form release agent is automatically siphoned out
of the container and then mixed with water in a venturi
mixing chamber. No measuring is required. To stop the
flow of ready-to-use product, the mix valve is simply
closed. Anyone can operate the Mix Station and achieve
consistent results.
|
Q: Do some form release agent manufactures actually use recycled transformer oils in their products?
| | A: Yes. Unfortunately,
some manufacturers have started using used electrical
transformer oils in their products.
Obvious health concerns for workers exposed to these materials
include the possibility for higher than normal
concentrations of high molecular weight aromatics (HMWA)
and polychlorinated biphenyls (PCBs). Nox-Crete
uses only virgin, severely hydro-treated naphthenic
distillates in their concrete form release agents. These
severely hydro-treated, distillates are basically one
step away from being edible. They contain 0 parts per million
(ppm) of PCB and between 1-3% or less HMWA. The
materials used by Nox-Crete in their form release agents
meet all current and proposed OSHA requirements for
worker safety.
|
Q: What’s the
best release agent for reducing buildup on aluminum forms?
I have
a residential poured concrete wall business. We use aluminum forms to
construct footings, basement walls and
stem walls. Please recommend a reasonably priced
form release agent that is effective at minimizing
concrete buildup on
my aluminum forms.
| | A: Nox-Crete
offers a ready-to-use, water based form release agent
designed specifically for aluminum forms
called
Alumi-Nox E.
In addition, we also manufacture a super
concentrated form release agent, also designed
specifically for aluminum forms, called
Alumi-Con.
Alumi-Con requires the use of the Nox-Crete
Mix Station
to ensure proper dilution and mixing. Both products are less
expensive than petroleum based alternatives and
equally effective.
|
Q: Are there
low odor form release agents?
My two
sons and I pour concrete basements for residential construction.
We are tired of smelling like diesel fuel all day
long. Does Nox-Crete manufacture a form release agent designed
for aluminum forms that does not contain diesel fuel?
| | A: Yes.
Nox-Crete manufactures two water based form release agents
designed specifically for aluminum forms.
Neither product contains diesel fuel or has any appreciable odor.
The products are
Alumi-Nox E
and
Alumi-Con.
We also offer water based form release agents suitable
for all forming surfaces which are low odor.
|
Q: How often
do water based form release agents need to be mixed?
I
understand that water based form release agents are emulsions of organic
materials and water and that all emulsions
require mixing. My question is, how often does a Nox-Crete water based
form release agent require mixing? What’s the
best way to effectively mix a 55-gallon drum or 275-gallon tote?
| | A: Nox-Crete
recommends mixing all water based form release agents a minimum
of one time per day. To mix a
55-gallon drum or 275-gallon tote, use the
Nox-Crete Drum Agitator
or
Tote Agitator.
The agitator is inserted on
top of the drum or tank and then simply hand turned a few
revolutions to mix.
|
Q: How
does the Mix Station work?
| | A: Nox-Crete’s
Mix Station
is designed to dilute and mix Nox-Crete’s line of
super concentrated form release
agents. The Mix Station is positioned on top of a 55-gallon
drum or a 275-gallon tote. A water hose is attached to
the Mix Station at one end. At the other end is a mix valve.
When opened, the mix valve automatically siphons
the super concentrated form release agent into the venturi
mixing chamber where it is mixed with water at the
proper dilution ratio. The fully mixed and properly
diluted form release agent then exits the Mix Station
in a ready-to-use form. When enough ready-to-use release agent has
been produced, the mix valve can simply be closed to
stop the flow. Anyone can effectively operate the
Mix Station and achieve consistent results.
|
Q: Why are
our concrete forms not lasting as long as they use to?
We use
inch and one-eighth overlaid plywood forms to construct residential
basements and stem walls. For some reason
we seem to be getting fewer pours on our forms. Is the reduced life
of our forms related to the quality of the plywood or is
it due to the use of an ineffective form release agent?
| | A: Although
the reduced form life you are experiencing could be the
result of many factors, the most likely cause
of your problem is increased alkalinity of the concrete.
The addition of certain pozzolans to concrete, such as
Class C fly ash or blast furnace slag, can increase the
pH of fresh concrete, causing increased damage to
overlaid plywood forms. To maximize your overlaid plywood
form life, restrict the use of highly alkaline containing
pozzolans in your concrete mix design and use Nox-Crete
form release agents on your forms. Nox-Crete’s
chemically reactive form release agents react with
calcium hydroxide (lime) in fresh concrete to form metallic
waterproof soaps which, over time and through use,
waterproof plywood form surfaces and effectively restricting
further penetration of destructive alkaline bleed
water.
|
Q: How
safe are Nox-Crete form release agents?
I am
concerned about worker safety for the laborers on my crew. How can I be
sure I am choosing the safest products for
them to use?
| | A: Nox-Crete
form release agents are designed to meet and exceed all
OSHA standards for worker safety. No
recycled or reworked raw materials are used in any
of our products. All naphthenic distillates used are severely
hydro-treated to remove high molecular weight
aromatics (HMWA). For added safety, choose one of our waterbased
form release agents which use water to replace
up to 88% of the petroleum carrier.
|
Q: What’s
the best way to remove concrete buildup from aluminum forms and prevent it from reoccurring?
We use
brick-textured aluminum forms to construct residential poured concrete basements.
The release agent we have
been using becomes so thick in the winter that we can’t
spray it through our sprayer. As a result, our forms have become
covered with concrete buildup. What should we do to remove
the buildup and what form release agent would you
recommend that we use?
| | A: Nox-Crete’s
Form Clean
is ideal for removing hardened concrete buildup
from aluminum forms. Form Clean
functions as both a release agent and a form cleaner, allowing
you to keep your forms in service as you clean
them if you prefer. Apply Form Clean as you would your regular
release agent immediately after form removal.
Over time (usually about 2 weeks) through use the buildup
will soften and the forms will become clean. Once the
forms are clean, use
Alumi-Nox E
or
Alumi-Con
as your
regular release agent to minimize buildup in the future.
|
Q: How
do I take advantage of the savings offered by water based
products in areas where freezing occurs?
I would
like to use a less expensive water based form release agent, but I live in a part
of the country where freezing
temperatures occur during the winter months.
I am concerned about the product freezing during the winter. Any
suggestions?
| | A: Any of our super
concentrated form release agents can be stored under
freezing conditions prior to dilution
without concern for damage from freezing. The super
concentrates can then be mixed with water, taken to the job
site and applied at temperatures above freezing.
Only petroleum based products should be used at temperatures
below freezing. To maximize savings, consider a
cost averaging approach where a petroleum based product is
used in the winter and a water based product
is used in the spring, summer and fall. |
Maintenance and Protection for Forms and Equipment
Q: What’s the best way to keep our paving machines free of concrete buildup?
We operate several street-type paving machines. Does Nox-Crete have a product we can use to soften existing concrete
buildup and to keep new buildup from sticking?
What product and procedure do you recommend for removing vinyl tile adhesive
residue from a concrete floor surface?
| | A: We manufacture
an equipment maintenance product called
Deactivator.
It is available in both petroleum and
water based formulations. To clean existing concrete
buildup, spray it with Deactivator. Over time, Deactivator
will soften the buildup, allowing it to be easily
removed with a pressure washer. As a maintenance product,
Deactivator should be applied to your paving machine
at the end of each work day. Deactivator will penetrate and
chemically deactivate the set of fresh buildup. In
addition, all surfaces treated with Deactivator will be protected
from the adhesion of any new concrete buildup.
|
Q: Is
there an option for removing hardened concrete buildup besides chipping?
Our
company specializes in heavy highway construction. Accordingly,
we operate mobile concrete batch plants, trucks,
and paving machines that get covered with concrete buildup.
Is there one product we can use to reduce the costly time
spent chipping off hardened concrete buildup?
| | A: To reduce
time spent chipping off hardened concrete buildup we
recommend the regular use of
Deactivator.
Deactivator , available in both petroleum and water
based versions, can be used to soften existing buildup and to keep
new buildup from bonding to mobile batch plants, dump
truck beds and paving machines. At end of the work day, after
pressure washing to remove soft buildup, spray apply a
liberal coat of Deactivator over all surfaces expected to receive
concrete buildup. Deactivator will not harm painted steel
surfaces and will prevent new buildup from bonding to coated
surfaces.
|
Q: Which
product is best for cleaning hand tools?
We seem
to have a problem removing hardened concrete buildup from our small hand tools.
Which product do you recommend, Kem-Ex-It Plus or Deactivator?
| | A:
Use
Kem-Ex-It Plus
to quickly remove hardened concrete buildup from small hand tools.
Small tools can be soaked in
Kem-Ex-It Plus while larger tools will require
brushing on successive coats of Kem-Ex-It
Plus followed by scrubbing the
buildup with a stiff bristle scrub brush.
Kem-Ex-It Plus will not cause rust to form
on steel tools, such as trowels, and does
not have an offensive odor.
|
Q: How do we
season our new aluminum forms?
Our company recently purchased
new set of aluminum forms for use in constructing residential poured wall basements.
Please recommend a product and procedure for seasoning our new forms.
| | A: All new
unseasoned aluminum forms must be seasoned prior to the first use.
Before seasoning a new set of
aluminum forms, all traces of mill oil must first be removed.
To remove, spray a solution of trisodium phosphate
(TSP) detergent and water on the form surfaces to be seasoned,
scrub with a stiff bristle brush and rinse with
water. A uniform coat of Nox-Crete’s
Seasonox
should then be applied to the form surfaces. After 20-30 minutes,
the form surfaces should be gently rinsed with
water to remove any unreacted Seasonox . Prior to use, the forms
should be treated with Nox-Crete’s
Form Clean
and used as the release agent for the first 3-4 pours. After this,
Alumi-Con
or
Alumi-Nox
chemically active aluminum
form release agents can be used.
|
Q: What’s
the best way to remove hardened concrete buildup from aluminum forms?
Please provide a product recommendation
and procedure for removing existing hardened concrete buildup
from aluminum forms.
| | A: Use Nox-Crete’s
Form Clean
to remove existing hardened concrete buildup on
aluminum form surfaces. Best
results are obtained if the Form Clean is spray applied
immediately after form removal while any new buildup is
still green. Continue to apply Form Clean liberally,
in place of a form release agent, until forms are clean.
|
Q: Do you
have a product that prevents rust formation?
Our company is in the
precast concrete business. We have a problem with the formation
of rust on our steel forms stored
outside for short periods of time. How can we
quickly and cost effectively remove existing rust and prevent the formation
of new rust on our idle forms?
| | A: Existing rust
steel forms is easily removed by scrubbing the rusted
surface with
Kem-Ex-It Plus.
Once the
effervescent action of Kem-Ex-It Plus has stopped, remove
any unreacted Kem-Ex-It Plus and the rust residue
with water. Once the forms are dry, spray apply a
liberal coat of
Formgard TJ
over all exposed steel surfaces.
Formgard TJ forms a tough, wax-like film on the form
surface that will prevent the formation of rust on steel forms
stored outside for up to 6 months. |
Tilt-Up Cure and Bondbreakers/Tilt-Up Concrete Construction
Q: How often
does Silcoseal need to be mixed?
I know that Silcoseal Select is a water based bondbreaker
and needs to be mixed before use. How often does it require
mixing and what is the best method for mixing?
| | A:
Silcoseal Select
is composed of a water based mixture of two liquids that are
mechanically dispersed into each other
to form a milky white emulsion. Unlike a solution, which will
always stay mixed, all emulsions will eventually separate into
two distinct layers. However, not all emulsions are the
same. Some emulsions have better emulsion stability (requiring
less mixing) than others. Silcoseal Select is a third
generation, water based bondbreaker with substantially improved
emulsion stability. For liability reasons, Nox-Crete
recommends that all Silcoseal bondbreakers be mixed each time
before product is withdrawn from the container. The
highly effective stability of our emulsions works as safeguard to help
minimize problems resulting from the lack of mixing
prior to product withdrawals later in the day. Mixing a 55-gallon drum
of Silcoseal Select is easily accomplished by using
the Nox-Crete Drum Agitator . Several turns of the agitator is all that is
required for sufficient mixing. One free Drum Agitator
is furnished with every four drums of Silcoseal Select purchased.
|
Q: How
well does Silcoseal Select resist removal by rain?
| | A: Once
Silcoseal Select has had 4 hours of drying time it
becomes resistant to removal from rain. Areas of high
humidity combined with cool temperatures may require
additional dry time to develop full resistance to rain removal.
|
Q: How
many coats of Silcoseal Select are needed for clean panel separation
from a casting slab floor surface?
How do you know when you have applied enough?
| | A:
Because every floor/casting slab is different, it is impossible to state specifically how many coats of
Silcoseal Select
are required to ensure clean panel separation. Several factors that affect the number of
bondbreaker coats required include: concrete mix design, finish, weather conditions, size of spray nozzle used,
product application rate, etc. Accordingly, Nox-Crete does not recommend a specific number of coats. Instead,
we recommend a visual test to verify adequate coverage of Silcoseal Select. Successive coats of the product
should be applied until all treated areas of the casting/floor slab remain uniformly dark in appearance for a
minimum of four hours following the previous coat. The development of lighter colored areas on the floor/casting
slab within the four hour time window indicates a porous condition requiring an additional coat(s) of bondbreaker.
When sufficient bondbreaker has been applied, the floor/casting slab will be uniformly dark in appearance with a
slightly sticky, wax-like feel (although Silcoseal Select does not contain any wax) to the touch.
|
Q: What’s
the application recommendation for “stack cast” panels?
Due to job site area restrictions, it will
be necessary for my company to “stack cast” panels on top of each other.
Are there
any precautions I should be aware of when using Silcoseal
Select in a “stack cast” application?
| | A: Stack
casting tilt-up panels presents a unique challenge for tilt-up
contractors. The challenge relates to
knowing when a sufficient amount of bondbreaker has been
applied between panels to ensure clean separation.
Unlike traditional tilt-up construction, where it
might be a week or longer between placing and finishing a floor/
casting slab and the placement of wall panel concrete,
in a stack cast tilt-up application, 2-3 wall panels are
placed on top of each other within 2-3 days.
Due to the lack of time for cement hydration before the placement of
additional wall panel concrete, the wall panel
concrete is still very porous. This makes it difficult to achieve
sufficient bondbreaker holdout on the stacked
panel/casting surface(s). The result is an increased potential for
stuck panels. To ensure that an adequate amount of
Silcoseal Select
is applied between panels, saturate the top
side of the panel to receive bondbreaker with water
prior to application of the bondbreaker. The water will control
the absorption of Silcoseal Select into panel surfaces,
providing uniform film holdout.
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Q: Can
I use another manufacturer’s cure and seal with Silcoseal Select?
If I choose to use another manufacturer’s
acrylic cure and seal to cure a casting/floor slab, can
I still use Silcoseal Select
as the bondbreaker?
| | A:
No. The solvents in
Silcoseal Select
may dissolve the
acrylic cure and seal, resulting in an incompatibility
problem. In order to use Silcoseal Select, the acrylic
cure and seal coating must first be removed.
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Q: Should
the hardener be applied before or after the tilt-up panels have been placed?
We would like to apply Duro-Nox
liquid floor hardener to the casting slab/floor slab
of a large tilt-up distribution center
project. Should we apply Duro-Nox to the floor before or
after the tilt-up operation has been performed?
| | A: It is
generally recommended that the tilt-up operation
be performed first.
Duro-Nox
can then be applied to the
floor after the wall panels and roof have been
installed. The application of Duro-Nox, or any other liquid floor
hardener, prior to the application of Silcoseal
bondbreaker reduces the bondbreaker’s rain
resistance and can
result in wall panel surface dusting.
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Q:
How do you remove residual Silcoseal bondbreaker from a casting/floor slab surface?
| | A:
The preferred method is to scrub the floor with a
mixture of Nox-Crete’s
Bio-Clean
diluted 1:2 or 1:3 with water
followed by a fresh water rinse. On large floors, the use
of an automatic ride-on type floor machine is
recommended.
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Q:
How do you remove Silcoseal bondbreaker residue from exterior wall panels prior to painting?
| | A:
Nox-Crete recommends that all exterior tilt-up wall
panels be properly cleaned prior to painting. To clean wall
panels, mix a solution of trisodium phosphate (TSP) detergent
and water by dissolving 0.5 – 1.0 lbs. of TSP in 5
gallons of water. The mixture should then be sprayed on the
wall panel and allowed to stand for 15-20 minutes.
After this time, rinse the TSP residue off the wall
panel surfaces using a minimum 2000 psi pressure washer
equipped with an oscillating spray nozzle.
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Q:
Does Silcoseal contain wax?
I’ve heard that some tilt-up
bondbreakers contain wax that could interfere with
the subsequent adhesion of floor adhesives
and coatings as well as wall panel patching materials
and paints. Do any of the Silcoseal bondbreakers contain wax?
| | A:
No. Silcoseal bondbreakers do not contain any wax.
However, some manufacturer’s bondbreakers do
contain wax. Wax is difficult to remove and
often interferes with the adhesion of floor
and wall panel paints,
coatings, and patching materials.
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Q:
What does “osmotic effect” mean?
I have heard this term used
and would like to know how it relates to tilt-up
construction.
| | A:
In the tilt-up industry, the term “osmotic effect”
refers to the migration of water out of a tilt-up wall panel and
into the casting slab during the critical panel
concrete hydration process. A gradient is formed when wet concrete
from a freshly placed wall panel is cast against
a casting slab with lower water content. This results in water
being drawn out of the panel concrete and into the
casting slab through a process called osmosis. The
moisture concentration difference between the wall
panel and casting slab is directly related to the osmotic force
or pressure attained to reach equilibrium between
the two slabs. The “osmotic effect” is the incomplete hydration
of the cement on the down side panel surface
resulting from the loss of water due to migration into the casting
slab through osmosis. Damage caused by the “osmotic effect”
can range from minor panel surface defects such
as dusting to complete skin pull-off, as deep
as 1/16 inch in depth in the more severe cases.
|
Q:
What is the preferred method of applying Silcoseal bondbreaker to a casting/floor slab?
Q:
Can I use a Silcoseal bondbreaker to cure my casting/floor slab?
| | A:
Yes. In fact, it is recommended that the floor/casting
lab of all tilt-up projects be cured with Silcoseal cure
and bondbreaker. The cure coat is the most important coat
and will provide the foundation for the subsequent
bondbreaker coats.
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Q:
What are the other tilt-up “Partner Products” Nox-Crete manufactures for tilt-up construction?
What are the incentives for my
company to consider their use on our future tilt-up projects?
Q:
Can I use an evaporation reducer, such as Nox-Crete’s Monofilm,
to control surface bleed water evaporation on a tiltup
casting/floor slab prior to the cure coat application of
Silcoseal cure and bondbreaker?
| | A: Yes.
Monfilm
is compatible with all Silcoseal
cure and bondbreakers and is one of the component products
in our
Tilt-Up Partner Products.
It is extremely
effective at reducing rapid surface bleed water loss and the
resulting formation of shrinkage cracks.
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Q:
Are there any states within the USA whose volatile organic content
(VOC) regulations prohibit the use of Silcoseal
Select?
| | A:
No.
Silcoseal Select
meets all current State and
Federal VOC regulations and can be used in all 50 states.
|
Q:
Is it true that federal and state DOT regulations do not
require transport drivers to have a hazardous materials
endorsement on their driver’s license to
transport Silcoseal Select?
| | A:
Yes. The flash point of
Silcoseal Select
is
over 100°F which, for DOT purposes, results in the product being
classified as “Not Hazardous” and therefore,
does require a hazardous materials endorsement on the driver’s
license of anyone transporting the product.
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Q:
How can I prevent wood sugar migration from particle or
press board used to form reveals in tilt-up panels?
| | A:
Nox-Crete’s
Clear Pre-Form
is a single component,
moisture-cured, polyurethane wood sealer that is extremely
effective at preventing wood sugar migration from
press board and particle board used in tilt-up construction. For
maximum effectiveness, all sides of the wood
reveals should be sealed. Only partial sealing of the exposed sides
will not effectively prevent wood sugar
related panel surface defects..
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