Always cut away from yourself when working with a utility knife, especially when cutting through something sturdy like wood. You may need to make the hole or crack slightly bigger before you can begin repairing it. It’s much easier to repair a larger hole free from damaged wood than it is to repair a smaller one that’s fragmented or broken, though!
The door isn’t actually 100% hollow. There are a series of diamond-shaped pockets inside the door. If your first bunch of material falls inside the door, keep adding more. You’ll eventually fill the section up. [3] X Research source
Don’t worry about the foam flowing out of the hole a bit! You’re going to cut the extra off. Look for the “low expansion” or “low rise” foam if you want something a little easier to work with.
Check the instructions on your own brand of insulation foam for more guidance on how long it will take to dry. Some foams may require longer drying times.
If it gets difficult to trim the foam near the face of the door with your utility knife, switch to a razor blade. Don’t worry if you remove a little too much foam. You’re going to fill it in.
Auto-body filler is a compound that will give you a very strong door, but it can be quite difficult to work with. It will normally come packaged with a hardening catalyst designed specifically to activate it. Some auto-body fillers do not need to be mixed.
Spackle is readily available, affordable, and very easy to work with. This repair won’t last decades the way auto-body filler will, but this will 100% get the job done. If you don’t have spackle or auto-body filler, you can use wood filler instead.
Check the instructions on your spackle or auto-body filler compound for more information on how long it will take to dry.
Repeat this entire process for each hole or crack on the door.
If you only want to paint or stain the repair, that’s totally fine. It may stand out a bit but if it’s not a commonly used door or it’s in an inconspicuous area, that may not be a big deal. If you want to remove the door from its hinges entirely, you can do that as well. Alternatively, you could use painter’s tape to tape off areas you don’t want to paint over.
If you can, bring in a sample of the door to help match it—such as a piece of the door you cut away when first repairing it.
If you’re worried about making a mess, lay down a drop cloth or some old newspaper underneath the door before you begin painting.
Check the instructions on your chosen paint or stain for more information on the expected time it takes for it to dry.
Many interior paints and stains will take several days to cure completely. Be careful with your repaired door for 1 week after painting it to avoid damaging your coat of paint. You can apply as many coats of paint or stain as you want, but 2 or 3 coats will normally be plenty to make your door look fantastic.
