We’ve all seen it: you open an old can of paint, and it has separated into a thick solids layer on the bottom and a clear layer on the top. Generally, we mix it back up and put the paint back into service, but what if we didn’t?
I have always assumed that the thick layer on the bottom was the pigment particulate, and that the clear layer on top was the latex acrylic blend (or whatever kind of paint you are using).
On other projects, I have used clear acrylic (no latex) to add a gloss coat on top of a flat color paint (I wanted to use up the last of the flat paint but wanted a gloss coat for stain resistance). It worked great.
So, I was wondering if I could pour off the clear layer from a house color we don’t use anymore and use it as a clear topcoat for other projects. Yes, I could (and will) just try it, but this seems like something someone knows the answer to already and could save me a lesson learned.
Not sure about that, but if you buy a “mixing base” paint that says “must have pigment added before use” and use it without pigment you get a bucket of sealant that dries almost clear. Don’t ask how I know…
I stopped in to my local Sherwin Williams and asked about this. The clerk said they “wouldn’t recommend it” but they did so in a tone that made it seem like they weren’t really sure what would happen.
So, I ran simple experiment: I carefully wetted a foam brush with the clear part of separated paint and applied to a three wood scraps of different species. I took pictures intending to show the results but the effect was so underwhelming that there wasn’t anything to see. There certainly wasn’t any kind of “finish” to speak of. Probably it was mostly just water.
I’m glad that I gave it a try because I’ve always been curious but at least for acrylic latex paint, you can’t use the clear part as a clear coat finish.