Any tips on removing spattered paint from old plastic signs without damaging the plaster or painted designs.
Not sure whether the spatter is water based or oil based.
Here is a video showing the spattering:
If it's latex paint, denatured alcohol, paint thinner (mineral spirits) or lighter fluid will remove the paint and shouldn't hurt the plastic.
If you are ever in Minnesota, you can buy Schmidt memorabilia to your heart's delight.
Sometime during my 24 Touring's 48 years in a barn, someone painted the barn and got white overspray on the back of the car.
I removed it by applying spray-on paint stripper then removing it after 10 seconds. I experimented...initially only letting it sit for a second or two and then lengthened that time interval. Since you're dealing with a different surface and paint, this may not be ideal for you...but I figured I'd let you know what worked for me.
My aim was to preserve the beautifully aged, original paint underneath. It was entirely successful.
Most plastics don't allow paint to adhere too well...it's too slick. I'd try something mild first, like hot water and dish soap. Just wet a hand towel with the solution and place it over the paint, letting is sit for a few minutes and see if one of those plastic dish scrubbers that look like steel wool will loosen it.
Oh.....unplug the sign first.
product named Goof Off will remove latex paint and shouldn't hurt the sub straight About $4.00 a can. I used it for years.
My wife uses WD40 to remove black magic marker form many things, and also black shoe marks from the floor.
Worth a test.