I have a Dewalt DC725 cordless drill. I was recently drilling some holes through a plasterboard ceiling and I guess the drill has been jammed with plaster dust because the chuck is stuck in the fully open position.
I thought that if I removed the chuck I could replace it, but I can't get it off. I have removed the holding screw from inside, but as it is jammed, I can't tighten it around an allen key to unscrew the chuck.
Thanks a lot in advance!
Best Answer
Prop the drill upside down in a glass filled with warm muriatic acid for a few hours to dissolve the packed calcium sulfate, followed by a couple of whacks on the chuck with a hammer; repeat as necessary. Rinse and dry thoroughly afterwards as muriatic acid is a strong oxidizer that will quickly rust high-carbon steels if left metal surfaces exposed in air.
USE CAUTION as muriatic acid is actually hydrochloric acid and can burn you and your clothes; wear gloves and eye protection. You can find muriatic acid in the pool cleaning section of the big-box hardware stores.
I use this technique to dissolve impacted gypsum dust from my Dremel chucks.