Is there a clear finish for walls painted with flat paint?

I need to know if there is a clear satin finish that can be applied to interior white flat paint.Is there a clear finish for walls painted with flat paint?
never heard of one but call some place like Lowe's and ask someone in the paint departmentIs there a clear finish for walls painted with flat paint?
polycrylic makes a satin finish clear


but it would be more cost effective just to repaint it in with satin paint. polyurethane sticks only to polyurethane and is great for floors but not for walls or ceilings
No, normally you would determine ahead of time the sheen of the finished product. There ARE clear varnishes and polyurethanes, but they are for wood..
your best bet would be to just repaint w/ a satin paint. as long the colors match and you have a good roller it should only take 1 thick coat. (and i have painted satin over flat- that flat does not show thru like if u were to paint flat over another sheen)
It would be a lot easier to just put another coat of paint on with the finish that you want. If you put polyurethane or any other type of sealant on, you are most likely going to have a huge problem if you ever want to paint it again. Most poly's don't dry perfectly clear in any case, they then to turn a light yellow or amber.
You can use clear untinted polyeurathane