No you need gold size to put it on in my experience. It needs to go on one hit and without getting glue on you, the rest of the leaf, anything else in a 30 mile radius.
Gold leaf is ridiculous thin....it basically will float way on a radiator current!
The size stays " open" (tacky) for various lengths of time depending on product. Glue wont work in my experience, because its wet. Size is essentially dry when you apply the gold. Wet glue will flood the leaf and it will ball together on the surface with other bits / get onto the gold / clog up the brush......generally end up with a bloody terrible mess!
Its not hard, but it is a skill and when you see professionals do it.....
You will need a very soft brush....i use makeup brushes......
It also needs a fair long time to dry out after fully, before you put clearcoat over it....light coat mist first, or you will dissolve the size!
With 3 coats of clear, mine handles stones etc, just like paint...so no problems.
Gold is either rose ( copper leaf) or normal ( brass) unless you want to push the boat out and get real gold! The advantage is real gold doesn't corrode and you can engine turn it or buff it to a smooth uniform finish......never done that, as we used fake stuff....even the silver is actually alluminium leaf!