Woodland Scenics Foam Putty

Just on principle, if you received it with that "expiry date" I say send/take it back. You probably will not get the results you want.

From the info on the Woodland Scenics web page, it looks like you've bought lightweight spackle compound. It's a very light, foamy texture kind of like dessert topping.

If you do go ahead with it, you might be able to soften it a bit with water, but usually once that stuff starts to dry out, there's not much that can be done.

Andrew
 
Sounds to me like you have dealt with someone you don't want to do business with again. If the Woodland Scenics product is light weight spackle, get a tub from your local home improvement store. It is probably less expensive for more product that way than from Woodland Scenics anyway.