first, you may want to try something else other than elmers glue. i've had no end of trouble using it.

i'm not sure what the situation is as i don't know what the surface looks like, but bumpiness can be caused and remedied by a number of things. if by bumpy you mean wrinkly, and you are using the paper stips method, it may be because your strips are too wide. if you put a sheet of paper on a table, it stays flat against the surface. if you put a sheet of paper into a cerial bowl, it's no longer smooth. it can't contour to the surface. the thinner the stip, the less it warps.  bumpiness can also  be caused by air bubbles. you might not see then when laying down strips, but they may show up and warp the surface when it starts to dry. many bumpy issues can also be solved by sanding.