Classic Acid or Nexus Stains Application: there are many different methods
of applying acid stains. Here is one of the many ways to complete the task. This is
the most basic method that we prefer and use for most of the applications.
First you need to know how does Acid react with concrete? Acid stain is
water based liquid carrying mineral salts and acid. The acid mixes with the cement to
force a chemical reaction changes the color of the cement similar to a forced rusting.
When highlighted with the proper sealer, this effect gives the natural rock glow that
attracts so many people to acid stained concrete.
Surface preparation is one of the most important steps of the acid staining
process. By cleaning the surface with Classic Concrete Degreaser CW301. The
concrete must be free of debris, dirt, and oils. On Old concrete acid stain will only
work on the cement portion of the concrete in other words you will get a lighter color,
and it will not stain rocks or any exposed surfaces.
You may want to consider Classic water base stain if your Concrete has been acid
etched or washed with muriatic acid it may not work with acid stains. You may get a
much lighter color. Often surfaces inside an existing house will have dry wall mud,
paint, wood stains, tile adhesives, carpet adhesives, grease, pet stains on the
concrete.
Acid stain is not an over coat it is an opaque coloring of the concrete. These spots
will show through if not removed. Especially mastic, dry wall, mud and paint, as these
get into the pores of the concrete and block the staining process. There are several
products available at a local hardware store such as adhesive removers and lacquer
thinners that can be used to clear these products from concrete in this circumstance.
These types of distressed floors will nearly always yield a varied character of finish
with a high degree of color difference area to area across the surface, and the
distressed sections lend character and depth to your floor. Cleaning one of these
floors to a stainable level is a considerable amount of work, but it is not impossible.
If you desire a more even finish, you should consider an overlay resurfacing Classic
(SOT260) Stamp Overlay White would give you more of a consistent in color. For
an indoor use (CMT2150) Micro topping smooth white especially on a floor that
has had glued tile or glued plastic carpet. Is highly recommended to do a small test
area first before starting the job. Concrete must cure at least 30 days.
Step 1
Before Staining Wear Rubber Gloves & Safety Glasses
When staining an area, cover the surrounding areas thoroughly with drop
cloths and clear plastic sheeting, including plants and furniture, so that nothing
is accidentally stained. Acid stains can be difficult, if not impossible, to remove.
The appearance of the finished product is very much influenced by the manner
in which the acid stain is applied.
The stain can be sprayed, mopped, brushed, rubbed, but the best way is using
a plastic sprayer and a soft push broom. Spray the stain using a plastic pump
sprayer no metal parts and using a soft brush broom for acid use then brush in
even circular strokes. When the residue dries, spray a second coat on top of
the residue to eliminate any brush strokes in the stain, unless the strokes are
desired in the finish. Brushed acid stain applies darker and more evenly. For a
more diffuse look, you may wish to spray the stain onto the surface without
brushing. Every slab of concrete is different, and acid staining is an artistic
process, its highly recommended do small test patches on the surface in
corners or where furniture will be to find the look you like the best.
Acid stain can be cut with water to lower the ratio of minerals, thus making
color lighter in shade. The best option is to test patch the concrete using
straight stain and stain cut one to one parts water to one part stain. If the water
content is too high, the acid won't facilitate the chemical reaction required to
make the color. This can be corrected by raising the acid content or using stain
extender. Some colors vary more by adding water content and many factors
determine how dark the stain will take such as age of concrete, cement content
and weathering. This is another reason to do as many pre stain tests as the job
site will allow.
As the acid stain dries and processes, a residue of alkali and minerals will form
on the surface of the concrete. This is natural and part of the reaction. Different
stains need different times to activate and fully color the concrete, generally
from one to eight hours. For multiple colors use test each color.
Be sure and check your stains activation time before starting the job to
insure full coloring of the surface. If you are going for the most color from a
giving stain, spray another coat of stain over the dried residue. Do not walk
on the wet residue. When the residue is wet, before it has been
neutralized, the stain is active and can retain impressions of your feet
or other marks from your feet or tools.
Step 2
Step 3
Removing the Residue When the residue has dried and the stain has been given
the proper time to process, the residue should be neutralized using Classic CW300
Neutralizer properly removing the residue is important for obtaining the best possible
acid stain appearance. For better results in removing the residue and preparing the
floor for sealing use around 4 gallon of water and 1 gallon of Classic Neutralizer
CW300 Pour on the residue scrubbing with a soft broom brush then using a shop
vacuum to eliminate the residue. Make sure you never allow it to run into the storm
drain, as it will stain it.
Then repeat the process, using straight water. After this step, all but a light residue
should have been removed. Let the floor dry and some lighter coloring may still be
visible indicating residue. Apply a clean, damp mop to the surface, wiping away any
remaining trace of residue. The floor should now be ready to seal.
Sealing the surface After the floor has completely dried from the residue
removal, the acid stain must be sealed with a proper decorative sealer. The sealer
may be brushed, sprayed or rolled on. I prefer spray on twice for most non-textured
applications, but I've included three different methods here using Classic Coatings
Sealers.
To spray the sealer on use a good all season deck sealant pump sprayer. These
usually come with three different nozzles. For spraying the sealer straight, use a
medium sized nozzle and thoroughly coat the surface. Classic Sealers dries very
smooth and flat to the surface, so the most important aspect is complete coverage.
A thick coating of sealer can sometimes take 48 hours to cure enough for foot
traffic, depending on humidity, etc.
To brush the sealer on, use a good quality brush so the bristles do not fall loose on
the surface as you apply. This is recommended for very rough surfaces or touch up
work. In a sprayed or rolled surface you can come across areas of a floor that are
more porous and absorb sealer, causing an uneven finish. You can touch these
areas up feathering the brush strokes without brush marks as the sealer cures to
the concrete.
Rolling is a popular method for applying the sealer. Be sure to use a very short
napped roller with no texture, as the texture of the roller can impress into the
sealer. It is much harder to get an even thick coating of sealer with a roller and is
the method most likely to have unpredictable finish results. If applied carefully this
is easiest of the methods.
To maintain the gloss of the surface, a good mop on acrylic wax is a good idea for
any acrylic surface, especially surfaces with high stress from pets or children, etc.