He just described "Bondo" which will work just fine
for what you are doing.

Just remember to make "small" batches cause when it
"sets", it sets in a hurry.




Limey Lurker wrote:


You need a polyester fine surface filler. This you will apply with a
semi-rigid spreader
which will push it into the cracks, and also make it more easy to
control the thickness of the coat. It will also set ready for sanding
in around 30 minutes. Don't buy the wood finishing
type; buy the vehicle finishing type which are just the same but only
half the price. A 4 inch spreader is probably the most comfortable
size for the job.
HTH