How do you sand tight grooves?

Sanding tight grooves can be tricky, but with the right techniques and tools, it can be done smoothly and efficiently. Here are some tips on how to approach sanding in tight spaces:

Use thin strips of sandpaper

Regular sheets of sandpaper are too thick to fit into narrow grooves. Cut down full sheets of sandpaper into thin strips around 1/2 inch wide. This will allow you to fold or wrap the sandpaper into the groove.

Try round-shaped abrasives

Look for cone-shaped and round sanding heads that are designed for detail sanding work. Attach them to a flexible shaft rotary tool to sand into corners and crevices. The shape allows them to get into tight spaces better than flat sandpaper.

Sand with the grain

Always sand in the direction of the grain, even when working in grooves. This will help avoid cross-grain scratches. If the groove has sections going different directions, change the sanding motion to match.

Use your fingers for leverage

Wrap a piece of sandpaper around one or two fingers on your non-dominant hand. Press it firmly into the groove to add leverage as you sand back and forth. This lets you apply consistent pressure across the length of the groove.

Try small detail sanding tools

Detail sanding tools like the 3M Sandblaster have thin, flexible sanding spindles that can get into grooves. Rotary tools with small diameter sanding bands can also work. Slow the speed down and gently sand back and forth in the groove.

Sand by hand for finish work

Use a sanding block or just your fingers to sand tight spots by hand. This control allows you to smooth out difficult end grain sections and feather out edges without over-sanding.

Work up through grits

Start with a lower grit sandpaper to flatten out the bottom of the groove, then switch to higher grits like 150, 220, 400 to refine the surface. Don’t skip grits, or the sanding marks from the coarser paper will remain.

Watch your progress

Check your progress frequently when sanding tight spots. It’s easy to overdo it, so inspect and feel along the groove to make sure you remove scratches before moving to a finer grit.

Use a hand scraper for problem spots

A card scraper or small cabinet scraper can help level out sections that are difficult to sand, like end grain. Take light cuts and test frequently until the surface is uniform.

Clean out debris

Blow out or vacuum sawdust between sanding grits so it doesn’t clog the groove. Remaining debris will scratch the surface as you sand with finer papers.

Apply finish carefully

Use a small foam brush, cloth, or cotton swabs to wipe on finish. Apply thin coats and wipe up excess to prevent drips or runs which will dry tacky in tight crevices.

Conclusion

Sanding inside of narrow spaces takes patience, the right tools, and a careful technique. But with some practice, you can learn to smoothly sand grooves, channels, and tight corners. The key is using thin sanding media, working through fine grits, and inspecting your progress frequently. Slow down and take your time for best results.