Can you put stain in polyurethane to darken the color?
More important is, that both paints are of the same kind (like: oil-based paint, acrylic paint, latex paint). Semi-gloss is more easily painted over then high gloss, but first better find out what the old paint layer is made of. Check with the help of alcohol - if paint comes off in any way when you rub it with a cloth of alcohol, it's latex or acrylic paint (and can be painted over with acrylics).
Latex paint is an indoor paint, which will not work very well on siding; you can paint it on, but it is going to peel off pretty quickly. Use an enamel paint.
You should never paint a deck, the paint will peel (unless you live in a very arid climate I guess. The deck may be stained, you can put either oil or latex stain over old oil stain.
Yes
Can you put stain in polyurethane to darken the color?
More important is, that both paints are of the same kind (like: oil-based paint, acrylic paint, latex paint). Semi-gloss is more easily painted over then high gloss, but first better find out what the old paint layer is made of. Check with the help of alcohol - if paint comes off in any way when you rub it with a cloth of alcohol, it's latex or acrylic paint (and can be painted over with acrylics).
Latex paint is an indoor paint, which will not work very well on siding; you can paint it on, but it is going to peel off pretty quickly. Use an enamel paint.
You should never paint a deck, the paint will peel (unless you live in a very arid climate I guess. The deck may be stained, you can put either oil or latex stain over old oil stain.
Yes
Yes, you can, but what a waste of money.
put a cover over the over paint then you get get the two paint mixed
yes but you cannot put latex on top of oil based surfaces You actually are NOT advised to put oil over latex surfaces, which is why you're supposed to prime will an oil-based (alkyd) primer. Latex and Polyurethane should always have a layer of oil-base beneath it.
If you are trying to protect a design, use three coats of acrylic polyurethane. If you are trying to repaint a chair that has been coated with acrylic paint, use acrylic paint again.
Yes, but remember that eggshell is already a changed color, so to speak. It's a colored white. Mix small amounts of the eggshell and other color to see your results. You may have to make several mixtures, so be sure to keep track of the amount of color you put into the eggshell so that when you get the color you want, you'll know how you got it and how to get it again.
you can paint over latex paint with latex enamel.
yes you can!