Should be good. Unless you've already bought the Bondo, I've had luck with a product called Evercoat Easy Sand. The number is 100421 on the last one I bought. Warning: It isn't cheap stuff. You'll find it at any body shop supplier. Might even find from Amazon but I get a discount at the supply store. Sands in about 20 minutes. I usually start with 180 to 220 grit dry and then finish with 320 wet and go over that with 600 in front of a handheld sponge type pad. I just had to repair a fender that was dropped this morning, in fact. Good luck!

PS...it lasts a long time. I have some that is 6 years old and it there are no problems with it.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end