Yes, the coverings all have different temperatures that should be used. I don't know what Ultracoat is, but Monokote is 275°. Now that temperature is only a guide. How you want the material to behave will change that temp a little bit. So do a little experimenting with it before you start applying it to the plane.

One side note on covering. The colors can vary a little bit from lot to lot. So whenever I build a plane I will save the unused covering material and label it for the plane that it was applied to. That way if I have to do any repairs on the plane later I know the repair covering will match the original.

Hope this helps

Ken