--- title: "Which sandpaper grit for plasterboard and filler?" description: "120 to 150 grit to level joint compound and 220 for the final pass, ideally on a mesh with a vacuum attached. The ranked options, the technique that changes the outc" url: https://atoneplace.net/which/sandpaper-drywall/ site: "At One Place" --- # Which sandpaper grit for plasterboard and filler? **Which sandpaper grit for plasterboard and filler?: 120 to 150 grit to level joint compound and 220 for the final pass, ideally on a mesh with a vacuum attached.** The commonest fault in this job is not the grit but the pressure: joint compound is much softer than the board's paper facing, so bearing down on a proud joint cuts through the paper, raising a fuzz of fibres that swells when painted and shows as a rough halo around the joint. That damage cannot be sanded out — it has to be sealed and skimmed. Better to apply thinner coats and sand less. Dust is the other issue. Gypsum dust is extremely fine, travels through a house and irritates airways, and some joint compounds have contained crystalline silica, so a mask and extraction are worth using even though the material feels innocuous. ## The options, ranked *Ranked best-first for the stated job. The third column is why the others exist.* | Option | Good at | Bad at | | --- | --- | --- | | 120-150 grit | Cuts dried joint compound quickly without scoring it into ridges. | Will cut through the paper facing of the board if you press on a high spot. | | 220 grit | The finishing pass that removes the previous scratches so the paint does not telegraph them. | Too fine to level anything. | | Abrasive mesh with dust extraction | Does not clog, and the vacuum takes most of the dust before it reaches the room. | Needs a vacuum and a compatible sanding head. | | Damp sponge sanding | Almost no airborne dust, and gentle on the paper facing. | Slower and it can soften and smear the compound if it is too wet. | ## Technique that changes the outcome 1. Apply thin coats and feather them wide so there is little to sand 2. Use a light touch and a flat block or pole sander to avoid dishing the joint 3. Check with a light held flat against the wall — raking light reveals every ridge 4. Prime before painting: bare compound absorbs paint far faster than board paper and flashes differently ## What goes wrong - Sanding through to the board's paper facing - Sanding without a mask or extraction; gypsum dust gets everywhere and irritates the airways - Painting straight over sanded compound without primer > Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here. ## Other sandpaper grit questions | For | Use | | --- | --- | | Bare wood | 80 to 120 to 150 on softwood, finishing at 180 or 220 on hardwood — and stop there, because over-sanding ruins stain. | | Stripping paint | 40 to 80 grit open-coat aluminium oxide or ceramic — but test for lead paint before sanding anything painted before the 1990s. | | Rusty metal | 60 to 80 grit to strip scale, 120 to 180 to blend — then prime the same day, because bare steel flash rusts within hours. | | Between coats | 220 to 320 grit with almost no pressure — you are knocking off dust nibs, not removing the coat. | | Plastic | Start at 320-600 wet for scratches, work up to 2000, then finish with a plastic polish — and keep it cool. | | Car body filler | 80 grit to shape, 180 to refine, 320 before primer and 400-600 on the primer before paint. | | Final finish | 400 to 600 dry, or 800 to 2000 wet on a fully cured film, followed by a polishing compound. | | Wet sanding | Silicon carbide wet-or-dry paper, water with a drop of detergent, a rigid block, and 800 grit upwards. | ## Common questions ### Which sandpaper grit for plasterboard and filler? 120 to 150 grit to level joint compound and 220 for the final pass, ideally on a mesh with a vacuum attached. ### What should I avoid? Sanding through to the board's paper facing Sanding without a mask or extraction; gypsum dust gets everywhere and irritates the airways Painting straight over sanded compound without primer ## Related pages - [Which sandpaper grit for bare wood before finishing?](https://atoneplace.net/which/sandpaper-bare-wood/) - [Which sandpaper grit removes paint?](https://atoneplace.net/which/sandpaper-stripping-paint/) - [Which sandpaper grit removes rust?](https://atoneplace.net/which/sandpaper-metal-rust/) - [Which sandpaper grit between coats of paint or varnish?](https://atoneplace.net/which/sandpaper-between-coats/) - [Which sandpaper grit for plastic?](https://atoneplace.net/which/sandpaper-plastic/) - [Which sandpaper grit for car body filler?](https://atoneplace.net/which/sandpaper-body-filler/) - [Which sandpaper grit for a final finish?](https://atoneplace.net/which/sandpaper-final-finish/) - [Which sandpaper should I use for wet sanding?](https://atoneplace.net/which/sandpaper-wet-sanding/) ## Sources - Typical range compiled from manufacturer specifications — At One Place (/about/)