Painting concrete porch
#1
04-22-00, 04:55 AM
How should I prepare a porch to repaint? Should I use a primer after scraping and cleaning or will two coats of concrete paint suffice?
#3
04-22-00, 11:13 PM
CONCRETE
There are a lot of considerations to think about before painting concrete floors:
1.How Old Is Your Concrete Floor?
2.How Clean Is Your Concrete Floor?
3.Is this a Re-paint Job?
4.Is moisture preventing paint from adhering?
5.Is there a hardener on a new concrete floor?
Answer to 1.
To be sure of a good, tightly-adhering paint job, new concrete floors need to age or
weather at least 30 days. The levels of moisture and alkalinity are much higher in
new concrete and these levels need time to drop so they do not interfere with a new
coat of paint adhering. Acid etching neutralizes the surface and provides a better bond for new paint. It is recommended for all unpainted or new concrete floors prior to coating. Prepare a liquid solution of one part muriatic acid with three parts water. Always add the acid to the water to avoid the splash of hot acid. Do not pour the water to the acid. Use a stiff bristle brush. Allow solution to remain on floor until it stops bubbling. Flush thoroughly with clean water. Flush the surface again if it is not dry in a few hours.After the surface has dried, vacuum to remove powder which is produced by the
etching process. When the floor is properly etched it should resemble the texture of
fine sandpaper. For industrial applications, more of a surface profile may be required
Answer2.
oil, grease, tar and other contaminants need to be removed thoroughly before
painting. If they are present when the floor is painted, they can cause peeling.
In a garage, it is especially important that deeply absorbed oils are completely
removed. Sometimes stubborn grease may continue to rise to the surface even after
the initial cleaning. After scrubbing, allow the surface to dry for a couple days and
see if any grease or oil stains re-surface. If they do, scrub again. In a laundry room
area, make certain all soap residues are removed. Clean the floor with a strong detergent solution avoiding mild dishwashing liquid. Use a solution of one cup trisodium phosphate type cleaner per pail of hot water. After scrubbing, rinse thoroughly. Scrape and sand to remove all loose and scaling paint
and to lower the gloss of any tightly adhering old paint.
We recommend Pittsburg Paints Aquapon® epoxy for garage floors. Proper surface preparation is important. Allow the epoxies to cure at least two days before exposing the surface
to hot tires from an automobile. Do not apply Aquapon® solvent-based epoxy (97-1 series) over existing paint films other than existing polyamide-epoxy films in good condition. Aquapon® WB epoxy (98-Line) can be applied over alkyd, latex and polyamide-epoxy films with proper surface preparation.
Is this a Re-paint Job?
If the floor has already been painted, the main concerns are making certain there is
no gloss remaining on the old layer of paint, no dirt or contaminants, and the paint
that’s there is tightly adhering. Do not acid etch previously painted floors. If the
concrete is old and crumbling, remove all loose concrete. Remember, paint cannot
"glue" down loose pieces of a surface. If the surface is deteriorating, it’s not the paint
that’s failing; rather, the pieces of the surface are releasing and bringing the paint
with it.
Is moisture preventing paint from adhering?
A Moisture Barrier is a Must!
Floors laid on-grade without a moisture barrier do not hold paint well. If the paint on your concrete floor keeps peeling, moisture could be seeping up through concrete
and pushing the paint off. This is especially common in basements. Most times a layer of plastic is put down before a concrete floor is poured to prevent this attack from moisture. Determine if the concrete floor has a moisture barrier. Take a plastic sheet (18"x18" at 4 mils thick) and tape down all the edges of the plastic. Keep the plastic in place for a minimum of 16 hours and then remove the tape and visually inspect the
underside of the plastic sheet and the concrete for any evidence of moisture. If any
is seen, the floor should not be painted.
Is there a hardener on your new concrete floor?
Hardeners Must be removed First!
Some new concrete floors may have a surface coating applied or may contain
additives which speed up the cure and harden the surface. Since these "hardeners"
may prevent good adhesion, they need to removed by some type of mechanical
abrasion.
------------------
Gary Goel/Owner Newkote Kitchen & Bath Refinishing
We are just a shade better...
gary@newkote.com
There are a lot of considerations to think about before painting concrete floors:
1.How Old Is Your Concrete Floor?
2.How Clean Is Your Concrete Floor?
3.Is this a Re-paint Job?
4.Is moisture preventing paint from adhering?
5.Is there a hardener on a new concrete floor?
Answer to 1.
To be sure of a good, tightly-adhering paint job, new concrete floors need to age or
weather at least 30 days. The levels of moisture and alkalinity are much higher in
new concrete and these levels need time to drop so they do not interfere with a new
coat of paint adhering. Acid etching neutralizes the surface and provides a better bond for new paint. It is recommended for all unpainted or new concrete floors prior to coating. Prepare a liquid solution of one part muriatic acid with three parts water. Always add the acid to the water to avoid the splash of hot acid. Do not pour the water to the acid. Use a stiff bristle brush. Allow solution to remain on floor until it stops bubbling. Flush thoroughly with clean water. Flush the surface again if it is not dry in a few hours.After the surface has dried, vacuum to remove powder which is produced by the
etching process. When the floor is properly etched it should resemble the texture of
fine sandpaper. For industrial applications, more of a surface profile may be required
Answer2.
oil, grease, tar and other contaminants need to be removed thoroughly before
painting. If they are present when the floor is painted, they can cause peeling.
In a garage, it is especially important that deeply absorbed oils are completely
removed. Sometimes stubborn grease may continue to rise to the surface even after
the initial cleaning. After scrubbing, allow the surface to dry for a couple days and
see if any grease or oil stains re-surface. If they do, scrub again. In a laundry room
area, make certain all soap residues are removed. Clean the floor with a strong detergent solution avoiding mild dishwashing liquid. Use a solution of one cup trisodium phosphate type cleaner per pail of hot water. After scrubbing, rinse thoroughly. Scrape and sand to remove all loose and scaling paint
and to lower the gloss of any tightly adhering old paint.
We recommend Pittsburg Paints Aquapon® epoxy for garage floors. Proper surface preparation is important. Allow the epoxies to cure at least two days before exposing the surface
to hot tires from an automobile. Do not apply Aquapon® solvent-based epoxy (97-1 series) over existing paint films other than existing polyamide-epoxy films in good condition. Aquapon® WB epoxy (98-Line) can be applied over alkyd, latex and polyamide-epoxy films with proper surface preparation.
Is this a Re-paint Job?
If the floor has already been painted, the main concerns are making certain there is
no gloss remaining on the old layer of paint, no dirt or contaminants, and the paint
that’s there is tightly adhering. Do not acid etch previously painted floors. If the
concrete is old and crumbling, remove all loose concrete. Remember, paint cannot
"glue" down loose pieces of a surface. If the surface is deteriorating, it’s not the paint
that’s failing; rather, the pieces of the surface are releasing and bringing the paint
with it.
Is moisture preventing paint from adhering?
A Moisture Barrier is a Must!
Floors laid on-grade without a moisture barrier do not hold paint well. If the paint on your concrete floor keeps peeling, moisture could be seeping up through concrete
and pushing the paint off. This is especially common in basements. Most times a layer of plastic is put down before a concrete floor is poured to prevent this attack from moisture. Determine if the concrete floor has a moisture barrier. Take a plastic sheet (18"x18" at 4 mils thick) and tape down all the edges of the plastic. Keep the plastic in place for a minimum of 16 hours and then remove the tape and visually inspect the
underside of the plastic sheet and the concrete for any evidence of moisture. If any
is seen, the floor should not be painted.
Is there a hardener on your new concrete floor?
Hardeners Must be removed First!
Some new concrete floors may have a surface coating applied or may contain
additives which speed up the cure and harden the surface. Since these "hardeners"
may prevent good adhesion, they need to removed by some type of mechanical
abrasion.
quote:<HR>Originally posted by cgarl1911@msn.com:
How should I prepare a porch to repaint? Should I use a primer after scraping and cleaning or will two coats of concrete paint suffice?<HR>
------------------
Gary Goel/Owner Newkote Kitchen & Bath Refinishing
We are just a shade better...
gary@newkote.com
