Should I apply painters caulk before or after I wash the walls and trim with TSP? I don't know if the TSP would damage the new caulk.

I'm going to be painting the interior of a 100-year-old house. Some of the existing paint is oil-based, some is latex, and most has lead. Some walls are dirty, and the rest are very dirty :)

We've replaced windows with new inserts and have re-installed the original trim. There are also quite a few nail holes, etc, to fill in. So we have a lot of caulking to do. I was planning to use acrylic latex caulk with silicone.

Thanks for any information you can give me.

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    If you were flipping, caulk would be fine in nail holes, but a better method would be to fill with spackle and sand. (You'll get a flatter surface... caulk will shrink when it dries, leaving a divot.) If your chosen product specifies that it's "paintable", then feel free to use it, but there's no upside that I can think of to using a siliconized product in place of regular painter's caulk. Commented Oct 9, 2016 at 0:43

1 Answer 1


Complete all required sanding, then clean everything including your planned TSP wash of the walls. Then caulk, prime (if necessary), and paint.

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