Rectorseal 81880 1-Pound Duct Seal Compound Gray

A wonderful product that fills those difficult gaps. Easy to use and stays flexible. D

Product appeared old and was sticky on my hand skin. Finally, after shaping product and leaving it several days to dry, I found product to have hardened, but not hard enough. I could reshape product and it wasn’t a good seal-used around the sides of ducted diffuser. Back to the drawing board. Or, next time you cut your floorboards to install a diffuser for the ducting heating, make sure you know how to use a hacksaw. Try to cut diffuser housing spot-on or you’ll be forced to search for sealants that perform lower tham expected.

Good

I love this stuff, where has it been all my life? I had an electrician tell me about duct seal and it changed my life (I mean in terms of if I need to cover holes for any cables/wires/pipes that come into or out of my home). This stuff is playdough for sealing holes and making sure no critters get into holes that might remain from wiring, piping or conduit. If you're someone that DIYs around the house, get this for the odd hole you might need to just plug and forget. Great value, it stays malleable for a long time, retains the color and great ease of use.

I used this to cover the hole with my thermostat wires coming into the thermostat this making the readings more accurate! It works really well, very cheap and will last me a lifetime! Highly recommend!