How to Use Sandpaper During Window Repair

red sandpaper
  • 2 hours
  • Beginner
  • 30
What You'll Need
Sanding block
Soft brush

This simple guide explains how to use sandpaper when repairing windows. Sandpaper is a simple way of removing paint and smoothing the surfaces of window frames. It is also an inexpensive method of restoring wooden window frames that have been damaged by the weather, wind, and rain.

Step 1 - Selecting your Sandpaper

You need to select the correct type of sandpaper for the job you are doing. Sandpaper is graded according to the number of grit particles per square inch. If there is a low number, the grit particles will be coarser and more abrasive on the surface. The type of sandpaper you wish to use will depend on how much repair work the window needs and the type of wood the window frames or sills are made of. The sandpaper can also be open-coat or closed-coat. Open-coat sandpaper has more gaps between the particles and is more suitable for working on wood than closed-coat sandpaper.

There are also several different types of sandpaper that are used for a variety of materials. For this project, you should look to use garnet paper, which is a reddish-brown color. This kind of sandpaper is thick enough to be used on wood without falling apart. If you are using a sanding machine you may wish to use ceramic sandpaper. However, exercise care with this type of sandpaper as it could remove large amounts of material very quickly.

different kinds of sandpaper

Step 2 - Removing Paint

Use a scraper to remove as much of the loose or chipped paint as you can. Use coarse-grained sandpaper of around 80 grit to remove any remaining paint that is flaking or damaged from window frames. You should aim to have the good wood underneath exposed. Make sure that you wear some thick gloves to protect your hands from any chips or splinters.

Step 3 - Sanding the Wooden Frame

The wooden window frame will probably have a curved or grooved surface. The sandpaper is an ideal tool to work on an uneven surface. For the frame, you should use sandpaper with around 80 or 100 grit so you don't damage the softwood.

Step 4 - Sanding the Window Sill

Window sills are usually flat and due to their exposure to the wind and rain, they often decay quicker than the rest of the window frame. You may find that you have to use coarser grit sandpaper to remove any flaking wood or splinters. When you have done this, use a sandpaper with 100 grit to begin sanding the wood to a quality finish. This will help prepare it for painting. When you are sanding the flat window sill, use the correct sandpaper wrapped around a sanding block. A sanding block will help you maintain a flat uniform surface all the way along the sill and also make the sandpaper easier to use.

Step 5 - Preparing your Window for Painting

Finally, you should use a soft brush to remove and wood dust and splinters that are left on the window. You should also wipe the window with warm soapy water to make sure that it is clean and ready for painting.