Several folks in this very helpful thread suggest using putty to fill nail holes during baseboard installation. I've got multiple contractors doing work on my remodel and one says caulk isn't a good choice because it will shrink and be noticeable later on.
The contractor who will be installing the baseboard wants to use caulk because he's using it to fill the gaps along the top edges between the baseboard and wall.
Does anyone have experience using caulk to fill holes in MDF baseboard?
Caulk is a bad choice, because it can't be sanded. You can't get it perfectly even with the flat surface, because it stick to everything it touches. You will end up with a slightly raised area around the hole, and it will show more readily than putty, because caulk has such a different consistency. And, yes, caulk will shrink just like putty, but unlike putty, you can't put a second coat on.
I did all the baseboards in a four bedroom house with large dining and living room about 10 years ago. This included cutting, installing, caulking, and painting. The house was sold about two years ago at which time I looked carefully at the baseboard work from before. It still looked great.
I had countersunk the baseboard nails by at least 1/8 inch (3 mm) and filled them flush with general purpose caulk at the same time as caulking the top of the baseboard to look finished. I used a bare finger on all the caulk to smooth. The caulk had at least 48 hours to cure before being painted.
I would recommend cold water putty.
