What’s a good paint stripper

Nov 23, 2003
I screwed up painting the return air grate. The grate is 67 years old and looked beat up. It had some rust also. I sprayed it with two coats of paint but didn’t sand the rust seeing it would of been a pain getting inside the slates. I painted it during the summer and the first time I put the heat on a loud whistling noise comes from the grate. I removed the grate and it’s whisper quiet. Can two light coats of spray paint effect the air flow? I know I should’ve removed the rust but I just wanted it to look better then it did before.

I called a few soda blasting places and they’re booked up till January. So I’m thinking paint stripper will remove the layers of paint. Any help?


Thinking of the air flow, I bet it's more likely the whistling is from air being channeled and forced around the flashing than the air flowing through the vents proper.

Try putting it back in place with some foam or - to test - strips of fabric or something around the flat flashing area/against the ceiling. Try running it then.
I replaced my old return air grate and the new one hummed at a certain tone. The fix was to take needle nose pliers and bend 1/3 to 1/2 of the louvers a little more open to disrupt the resonance that the air flow was causing with the new grate.
I took down the grate in past years and wiped the build up of dust off and then reinstalled it and it was quiet. I went online looking for a new one but I have a odd ball size and nothing fits. I might be crazy but it also seems there is a increase of air flow into the return?
Unless you messed with the fins, there shouldn’t be a change in noise. A few mils of paint isn’t going to do it.

More likely you didn’t screw it tightly, or something is crooked…
You may want to try a less toxic citrus or soy-based paint stripper. Other than that a product like Jasco, which contains rather toxic methylene chloride and methanol is usually effective but you should avoid skin contact and don't breathe in any of the fumes.
Did you have it turned around the other direction, where the lovers face left instead of right, or vice versa?
I tried it both ways and it still makes the loud intake noise. When I put my hand near the grille the noise gets louder.