I'm going to use J-B Weld QuikWood to fill the hole you see here.

Perfect product to fill the hole. Use the full amount you need to fill the hole. It needs to act as a solid plug. Press it into the hole so it gets into every nook and cranny. It's going to be harder than the surrounding wood giving it strength. Give it enough time to harden. You don't carve a new hole for the deadbolt. What you will need is a 1" spade bit and a drill to drill a new clean hole. Put some lipstick on the face of the deadbolt. Close the door and turn the deadbolt. The lipstick will leave an imprint on the door jamb where you need to drill the hole. Find the center and drill your hole. Clean the lipstick off the deadbolt and your all set.

Spade bit:

This installing a new deadbolt. You only need to the last part of the video.

Thanks! I'll check out the spade bit. I have a drill but might see if my neighbor can do that part for me. :-)

No matter what you do I think you need to add some reinforcement to your door.

Something like this.

William's method should work, but you may be able to avoid drilling the hardened filler by using a "softer" two-part putty (Bondo or a JB product that come in a tubes).

This is a trickier process. I am suggesting mixing the filler and filling the hole and turning the deadbolt into the putty before it sets. Details to consider:

- mix up a larger batch of filler and set it aside the extra on a paper plate so you an monitor how the filler is curing/setting up.

- cover the filled hole with plastic wrap or plastic from a plastic grocery bag and smear vaseline over the deadbolt.

- when the filler just begins to stiffen, close the door and turn the deadbolt so it extends into the filler and makes a hole. Continue to monitor the curing of the filler and retract the bolt after the filler hardens but doesn't fully cure. The plastic and the vaseline are intended to prevent the deadbolt from being glued into the hole.

- you can clean up the area around the hole before it sets completely (with a small chisel or flat bladed screw driver) to accommodate the strike plate.

JB weld is the wrong product for wood. The wood has been comprimised to a great extent. I suggest cutting the entire piece out with a jigsaw, replace with a hardwood THEN useing Liquid Nails (which is a construction staple for wood and drywall ) to cement the two CLEAN pieces of wood on all sides except the strick side. PRE counter sink screw holes, 4 at an angle, top and bottom sides and & 1 front of panel.NO MORE as you can weaken and split the wood. When all is dry, fill front screw holes with putty for cosmetic reasons. YES, this is a bit more work, but supper easy and doable for a beginner. I fear the whole you have at the moment is rotted, cracked, to large and to thin at this point to save. The cement of any kind WILL POP OUT at some point and all will be for not. REPLACE the wood with a new piece of 2x4. No exceptions. This will ensure a NEW jam for a strike plate.

Please do not do it. The hole is too large. Cut away all the spongy wood and the thin walls on the inside and outside of the door. Do not even bother to fit a piece of wood into the hole and risk breaking the this walls. Make it one big piece and fasten into place with your JB Weld. Now you will have solid wood to bore your holes for the hardware. Good luck

I would ream the area out square with a hammer and wood chisel and then glue a block of wood into the space. Fill in around the block with a plastic wood putty. Let dry and then sand. Put in new hole for your lock with the wood chisel after you mark out the proper size.

Best of luck William, fill the void with thin layers of JB Weld and allow to dry. I still think it best to make a 'dutchman' to fill the void. That would be a solid piece of wood sized to fill the part of the door you cut out.

Hence, the screws. Good luck on the repair. I hope it goes well!