I like to share this tip with you. One of best product I have ever used for fixing dents and filling joints is Patch-N-paint by Custom. This product goes on smooth, very light, it does not crack when drys, and has the same hardness as balsa so it sands beautifully. Next time you are in the process of preparing the surface for paint or covering try it. I got mine from home depot.

or, if you dinged your bit of balsa, you can wet it and iron it

Foxx,

Is this the same stuff as light weight spackling compound?

Chook you are right, that is what it says on the container , "lightweight spackling"., but I have used spackling compound before and never liked them because they are too soft and upon sanding it gives you a low spot. This particular brand must have a different formulation that works really well, it drys very fast ,won,t crack and sands well. I know you are a professional model builder so let me know what you think.

ditto. might need a bit of light sanding too after the balsa is ironed to get rid of some "bulge" in the surface

Red devil light weight spackle,buy the 1qt size and add 15 drops of yellow food color and 5 drops of red,,,mix it up for a good balsa match...take a damp cloth and lightly dampen area to be filled and then apply with flexable bondo spreaders,drys fast,no cracks,no shrink,sands perfect and lighter than balsa!!! can be thinned and cleaned up with water.