Which cleaner should I use to prepare an old buffet for chalk paint?

I have used TSP on furniture that is real "cruddy" (a few tablespoons of TSP in a spray bottle mixed with some water) and then thoroughly scrub the surface. Or more often than not, I use a mixture of vinegar and a bit of Dawn dish detergent mixed in a spray bottle. Use a toothbrush in the corners and around the hardware to get old crud off. Thoroughly scrubbing and rinsing well are as important as the cleaning agent you use, so make sure the residue is gone before painting. If there are dings & dents in the surface, you will want to fill those areas with wood putty and then sand and remove dust from those areas before painting. Good luck!

TSP is what I have always used. That stuff is magic!

Hello Pet! This website suggests using mineral spirits to get rid of grease and grime on older furniture before chalk painting. This person has LOTS of experience chalk painting and her website is a very popular one so I would go with her suggestion.

https://www.thepurplepaintedlady.com/2012/09/cleaning-furniture-before-painting-it

Hi, Pet!

TSP (tri-sodium phosphate) or TSP substitute is great for removing grease, buildup, etc. from surfaces prior to painting. I hope this helps!