The Basic Kit
Everything you need to finish a room, nothing you don't.
6-inch knife: Your workhorse for embedding tape, filling, detail work. Flexible blade, comfortable handle, this is the tool you'll use most.
10 or 12-inch knife: For spreading finish coats and feathering edges. Wider blade covers more area and leaves fewer ridges.
Mud pan: Holds compound while you work. Metal edge cleans your knife with each load. About 12 inches long works for most knives.
Sanding supplies: Sanding block or hand sander, sandpaper in 120 and 150 grits, sanding sponge for corners.
Paper tape: One roll handles a typical room.
That's genuinely all you need to start. Total cost maybe $50-75 for decent quality.
Knife Quality Matters
Cheap knives have stiff blades that don't flex with wall contours. The mud doesn't spread smoothly because the blade can't follow the surface.
Quality knives have blades that flex evenly across their width. They glide over bumps instead of catching. Edges are ground smooth to leave clean lines in the mud.
Stainless steel blades resist rust and clean easier. Carbon steel is fine but needs more care to prevent corrosion.
Handles matter for comfort during long sessions. Cushioned handles reduce fatigue. Cheap plastic handles get slippery when sweaty.
Major brands like Marshalltown, Kraft, and USG make quality tools. The mid-range options from these brands outperform cheap brands' best offerings.
Expanding Your Kit
Once you've done a few projects, additional tools make work easier:
4-inch knife: Detail work, embedding tape in tight spots, scraping.
14-inch knife: Wide finish coats, skim coating. Not strictly necessary but helpful for large walls.
Corner tools: Inside corner knife or roller speeds up corner work. Not essential but nice for rooms with lots of corners.
Pole sander: Extends your reach for walls and ceilings. Much faster than hand sanding from a ladder.
Mud mixer: Drill attachment for mixing setting compound. Not needed for pre-mixed, essential for powdered compounds.
Hawk: A flat platform to hold mud in your off hand. Lets you load your knife without constantly returning to the pan. Taping contractors consider this essential.
Professional Tools
These make sense for high-volume work or contracting:
Automatic taper (bazooka): Applies tape and mud simultaneously. Expensive ($800+) but dramatically speeds production. Not worth it for DIY.
Flat boxes: Automatic finishing boxes that apply consistent coats in one pass. Various widths for different coat stages. The time savings are real for large projects.
Corner roller: Rolls tape into corners quickly and consistently. Faster than knife work for production environments.
Power sander with dust collection: Makes sanding large areas faster and cleaner. Good ones cost $300+ but pay for themselves on whole-house jobs.
Stilts: Eliminate ladder work for walls and low ceilings. Learning curve but massive time saver once proficient.
Tool Care
Tools last when you maintain them:
Clean immediately after use. Joint compound is easy to wipe off when wet. Dried compound requires soaking and scraping.
Never let compound dry on knife edges. The dried buildup makes your next work rough and uneven.
Store clean and dry. Rust spots on blade edges affect mud application.
Replace worn blades. Bent, nicked, or corroded blades don't produce smooth results. New knives are cheaper than spending hours fighting bad tools.
Keep handles tight. Loose handles make control difficult and fatigue your hand faster.
What I Actually Use
After years of accumulating tools:
Most used: 6-inch Marshalltown knife. The blade has developed a perfect flex from use. I've refused upgrades because this one just works.
Second most: 12-inch knife for finish coats. Good blade, nothing special, does the job.
For corners: Basic inside corner knife. Could live without it but it makes corners faster.
Sanding: Pole sander for walls and ceilings. Sanding sponge for corners and detail.
Specialty: 45-minute setting compound mixing paddle. Use it every time I mix hot mud.
Almost never used: Most of the other stuff I've accumulated. The basics handle 95% of situations. The rest sits in a bucket in the garage.