Since the door is pretty much a custom size (33 5/8") I had to make a completely new jamb. With a door this massive and this heavy (75Lbs) I wanted a substantial jamb (none of this modern dinky crap that is barely 3/4" thick). My jamb was made from 1 1/2" thick stock. I used cedar since I had it on hand, but looking back, I should have used normal spruce 2x8s instead.
I routed a full 1/2" deep rabbet for the door (like all old fashioned jambs) using 3 passes with a router. If I had a much better, and larger table saw, I could have simply made the rabbets with 2 saw cuts, but with what I have, this was the most accurate method. Shown is pass 1 and 2 on 2 of the boards.
The corners are held together with four 3" screws each.
Fitting Hinges & Hardware
Here is how I precisely fit all my hardware for construction and cabinetry. This is a method I've developed on my own, but I am probably not the only one who does it this way. For the purpose of this tutorial I'll be referring constantly to a hinge, but I use the same technique to fit any kind of hardware that needs to be flush-mounted with the wood surface (locks, strike plates, catches, etc).
Start by mounting your hinge directly onto the wood exactly where it needs to go.
Neatly, and deeply, score around the edges of the hinge.
Because this particular hinge is inset about 1/2" lower than on a normal flat surface, I set up some support blocks on the other side (to keep my router flat).
Remove the hinge.
Set-up a router with a suitable bit and to the correct depth.
Hog-out the bulk of the material, and then carefully pare-away the remaining corners and edges.
If everything was done correctly, you should have a perfect, flat, and tight fitting recess.
The same exact method was used for the complicated shape of the strike plate. This one is done in 2 stages. The main flat portion is done first, then the plate is installed and the deep slots are marked. The plate is removed again, the deep slots are cut, and then trimmed.
Note: all these silver screws are temporary ones.
Door so far:
For even more strength on the hinges, I glued some 1/2" blocks where the screws are.
Next I need to prime and paint the jamb (at least the primer and one coat of white). It will get additional holes and putty when I nail it in place, but I want the bulk of it ready and painted before I install it, since this is the main door of the house.