Slakey Takes a Test
About 2 months ago I wrote about some paint testing, specifically isolating variables related to little white balls that were showing up in the paint (you can find that post here). I finally tested out the soaked Ace lime (Slakey) to see if that had helped to dissolve/breakdown the thicker grit.

It did not.
I mixed up a batch of ultramarine blue and painted 4 coats onto a test board. I didn’t really notice the white balls after the first 2 coats, but it was leaving a bumpier texture than usual1. By the 4th coat, the grit was very visible.
Not to be deterred, I filtered the paint through a tea strainer and re-applied 4 coats to the other face of the board. Still felt gritty after the initial coat and knock down (though slightly less) and still had white grit present, though not as much.
Unfortunately, Slakey has failed the test. I hate to waste anything, but it feels like any more work I put into trying to make this Ace lime work is just throwing good money after bad. When I first soaked it and it released a ton of heat, I should’ve known that something wasn’t quite right with it. If nothing else I can be an example of what NOT to do when it comes to trying out this lime for paint.
Guess it’s finally time to find a 50lb bag of type S…
I’ll have a lifetime supply and can even share it, but please don’t ask me to mail you a baggie of white powder.
I always knock down any raised grain after the first coat with a 320 grit sanding sponge. Subsequent coats feels fine, but the ace lime paint has always felt grittier after every coat.




Thanks for the detailed write-up, I'd call that conclusive.
Glad to hear you're getting a big old bag of type S—that should knock out one main variable.
Do your own math about costs and storage space needs, but I was happy to find Smaller volumes of true Type S are available here: https://atlaspreservation.com/products/type-s-hydrated-lime