Yes, you can,and it's very good for that use. However if the concrete is bare, you must apply an epoxy primer before the polyurethane finish.
Yes, as long as the polyurethane is oil-based.
Yes, after allowing a sufficient time for the base to dry.
To create a durable and visually appealing cement stone walkway for your outdoor space, follow these steps: Prepare the area by clearing it of any debris and leveling the ground. Create a sturdy base by laying down a layer of gravel and compacting it. Mix cement with water according to the instructions on the bag to create a thick paste. Pour the cement mixture into molds to create stone shapes, or use a trowel to shape the cement directly on the ground. Allow the cement to dry and cure for at least 24 hours before removing the molds or walking on the walkway. Once the cement is fully cured, you can add a sealant or stain to enhance the appearance and protect the surface. By following these steps, you can create a durable and visually appealing cement stone walkway for your outdoor space.
Cement can wick moisture from outside that will cause your paint to peel off. Look for a primer that will seal it first, then paint it.
It would if you put on a good latex primer first.
I use oil base enamel with oil base polyurethane. Tip: Make sure you allow it to dry completely before you apply top coat. Good luck.
base
Solvent based paint will use a special thinner, and generally be smellier till it dries. Water based paint needs no special thinner and is not smelly.
To apply polyurethane over paint for a durable and smooth finish, follow these steps: Ensure the paint is completely dry before applying polyurethane. Lightly sand the painted surface to create a smooth base for the polyurethane. Clean the surface to remove any dust or debris. Apply a thin, even coat of polyurethane using a high-quality brush or roller. Allow the first coat to dry completely before applying additional coats. Sand lightly between coats for a smooth finish. Apply multiple thin coats rather than one thick coat for better durability. Allow the final coat to cure fully before using the surface.
To properly construct a cement mailbox base, follow these steps: Dig a hole for the base of the mailbox. Place a wooden form in the hole to shape the cement. Mix the cement according to the instructions. Pour the cement into the form and level it. Allow the cement to cure and harden. Remove the form and install the mailbox on the base.
If you want to keep your paint color pure and cover your object and/or project with 1 or 2 coats, I wouldn't, it sounds like your trying to eliminate a step, I know they do it with stain and polyurethane but not with paint and poly. I think as long as its water-base poly & water-base paint (latex) its possible, try 1oz of paint, 1oz of poly and mix well and try it on a test piece to see if its to your liking. Good-Luck!
yes