If the cinder blocks are somewhere inside, maybe. Personally, I'd prefer to use a concrete primer.
you can paint over latex paint with latex enamel.
Water Based Latex Enamel is now available. Easy clean up.
Yes. Enamel means hard and many companies make a water based flat enamel.
Yes you can. As long as the enamel is a latex, or water base also. The only thing enamel stands for is the hardness of the paint after it has cured. Enamel is very hard making it the most durable for bathrooms, woodwork, kitchens. It can be either oil based or water based (latex stands for water based paint).
Do you mean oil based enamel, or alkyd enamel? It can, but you will have to prime it with a barrier coat of compatible primer for the new paint to stick to it. I would not recommend it though. If the latex paint has been around for a long time, you have a better chance of having your new paint last. Is this inside or outside? Is it exposed to temperature extremes? The latex paint will be able to expand and contract more than the oil based enamel. If you can imagine putting paint on a latex glove, letting it dry, then putting the glove on (stretching it) then you will have a good idea (although much more extreme) of what you are asking the paint to do. If you really must put an oil based enamel on top of latex. Use a good oil based enamel like Kilz or Zinnzer Bullseye before you paint it. After you put the barrier coat on, you will have a limited time to get the other paint on....check the directions.
If your cinder block is outside, primer it first, then use oil base.
Not directly. You will need to use a primer made to adhere to oil and will accept a latex topcoat.
Yes, but first lightly sand the surface to remove any gloss.
Yes, some do use that.
Enamel is a word used to describe a finish, not the formulation of a paint. It simply means a hard reflective surface. Many people mistakenly use the word enamel when referring to oil based paints. So. if you are asking if you can paint latex or acrylic paint over a latex or acrylic enamel the answer is yes, however, I strongly recommend you sand the old paint first to give the top coat "tooth". If you are asking about painting latex or acrylic over an oil based paint the answer is still yes, however you must first sand the old paint and apply a good quality primer to it. Check with a reputable paint retailer for the best brand in your area.
I would use Kilz latex primer.
Close to the same. Enamel just means that it's a hard finish. If you're painting a door, trim or anywhere that will be handled often and you must use a water based paint, an enamel is the way to go.