Choosing Your Varnish
Now is the time to decide what type of varnish you are going to use. Water based varnish is easy to clean up. It dries quickly so you can get more coats on in a day. It does not change the colours. When decoupage a surface that will be subjected to a lot of wear and tear such as a tea tray or table top, I use a water based floor varnish. If you are working on a project with a special colour scheme that must match something else exactly, then water based varnish is the one to use. If you like that warm antique glow, oil based varnish is the answer. There is something very special about a decoupage done with oil based varnish. Then there is Envirotex. This is best used on flat surfaces because it is applied by pouring. If the surface is uneven it will settle in the deeper parts and make a thick pool of resin. not good. It does save a lot of time though as one coat is equal to about 50 or 60 coats of varnish.
STEP 10 ... Varnishing.
Always follow the directions for drying and re-coating times on the label of your product. Humidity and temperature both affect how quickly your varnish will dry. The old rule that thin coats are always better than thick apply. As you apply more and more coats you will have to allow more and more drying time. And do not be tempted to try and speed up the drying by using a hair drier or putting the object by the fireplace. You could ruin it. A fan circulating warm air in the room is OK. You need to keep track of how many coats you have applied so have a sheet of paper handy and keep a record each time you apply a new coat. You must apply 20 coats of varnish to begin with. Don't let this frighten you, it is not that much. With water based varnish and summer weather you could possibly get in 5 coats a day so that is only 4 days. Allow the 20th coat to dry for at leas 24 hours and then sand gently until the entire surface is dull. If you sand through to the paper then you have not applied enough varnish and you must stop, colour in the paper where you sanded through and apply more coats, and more coats, You are going to apply a total of 60 coats of varnish.