Knowing how to properly clean your drywall tools of messy caked-on joint compound can extend the life of the tools for years and save you a good deal of time and effort. Professional drywall installers often refer to joint compound as mud because it can create just as much of a mess. Some brands of drywall tools can be expensive, and any DIY-er would want to prevent needing to replace such an investment due to lack of maintenance. Joint compound can harden on the tools in a relatively short time after completing a drywall installation, so cleaning them in a timely manner is also important.
Step 1 -- Scrape and Soak Tools
Scrape off as much of the dried joint compound as possible with the putty knife. You can also use your drywall taping knife for this if you do not have a putty knife handy. Make sure you have a bucket that is large enough to submerge your tools; a clean 5-gallon one should do nicely. After scraping, submerge your tools in the bucket of water for at least 10 to 20 minutes. If there is still stubborn joint compound stuck on them, soak your tools again for the same length of time.
Step 2 -- Scrub Drywall Tools
Once your tools are sufficiently soaked to remove all hardened compound, take them out of the bucket and dump the dirty water from it. Refill the bucket with clean water and then use the scouring pad to thoroughly scrub all traces of joint compound from your tools. Always use a dish scouring pad for cleaning your drywall tools, not a steel wool pad since the abrasive metal from this will cause scratches in the surfaces of the tools. A stiff scrub brush will also work as an alternative.
Remove and rinse the tools, and then dry them with a clean rag. A piece of old T-shirt works well. Be sure to dry all hard-to-reach parts, such as handle joints and fasteners. Be sure to wash off any joint compound from your hands as well. When pouring out water and cleaning your bucket, do not dump water down a kitchen sink; use a laundry room sink if one is available. Some areas have ordinances against dumping drywall residue down plumbing drains, so it is a good idea to check the local codes for proper disposal procedures.
Step 3 -- Apply Rust Inhibitor
Rust inhibitors most often come as aerosol sprays. Spray all of the metal fasteners on the tools with this compound, and be sure to do this in a well-ventilated area. Small screws and bolts on the handles of tools such has taping knives are prone to rust, so make sure they get a coat of rust inhibitor on a regular basis. Wipe off excess rust inhibiting spray from other areas of your tools with a clean rag. If you do not want to purchase more expensive rust inhibiting spray, standard WD-40 spray will work just as effectively. Always store your drywall tools in a dry place.