I got the following question from a reader:
“I’ve used Pactra Aero Gloss paints, sanding sealers, and balsa filler-coat products in my model building hobby for decades. Now that that manufacturer (and subsequently that product) apparently no longer exists, and I’m running out of their brand of thinner, I’m wondering if I can successfully use some other manufacturers’ lacquer thinner to thin the product I still have and for clean up? (Although the product seems to thicken as it sits inside the sealed glass jars, it never seems to fail coming back to life when I add thinner.)
The Pactra label said it contains methyl isobutyl ketone. I notice that lacquer thinners supplied at my local home centers have a different ingredient. What are your thoughts on me using these currently available products as my new source of thinner?”
Here’s my answer:
The short answer is that if you add the thinner and the solution doesn’t separate, curdle or produce a flaw called “cotton blush” when you spray it, the thinner is fine.