Step Four:The Doors

Solid wood, frame and panel doors are not the most difficult things to make, in principle, but they do require attention to details and are time consuming to do correctly. The most frustrating part of frame and panel construction is that if you do it wrong, you might not know it for a month or more, by which time the piece is finished and sitting in someone's home. So I don't approach doors lightly.

Each step in frame and panel doors can make an extensive blog itself, which I will do later. For now, consider this an overview of the process.

First off, I start with rough lumber. S4S (surfaced on four sides) lumber is fine for face frames, but it is too often warped or will warp when cut to use for doors which have to remain flat all on their own.

I start by selecting the straightest grained 4/4 rough lumber I can, being careful to avoid knots and rotten bits. Then I check the moisture content. If the lumber has been kiln dried and stored correctly at the lumber yard, it should be fine, but check anyway. If the wood is high in moisture, it will have to be dried which is a whole other process.

Next I cut the boards into lengths, allowing a few inches extra for each part. I usually do this with a circular saw. Rough boards are rarely straight and therefor dangerous to cut with a miter saw or radial arm saw. Jointing a shorter board is easier and wastes less material, so cut over sized lengths before jointing.

Once cut to rough length, I surface one face and one edge using a jointer (or in the case of boards too wide for my jointer, I use a surface planer and a jig I found in Fine Woodworking magazine.) Once I have a flat face, I plane the other face until the board reaches my desired thickness. I make sure to plane all my boards at the same time, assuring they are identical in thickness, which will help with a good joint later.

Here's a trick: As you surface lumber you will need to keep track of which sides have been worked. After cutting rough lengths I scribble on all sides of the board with a lumber crayon. Now, as I flatten each side, the marks are removed and I know that side is done.



Once the board is flat and has one flat edge (S3S) I rip the board down to slightly larger than the final width, usually 1/8" - 1/4" wider. Now I move back to the jointer and check both edges. Often after ripping, the board will bow a bit, which will require correction on the jointer.

Simply hold each edge against the jointer's guide rail and look for gaps. Any gap means the edge is not flat. Re-joint these edges, then rip the board again, this time to final size.



Now it's time to glue up the panels. Start by laying out your pieces and arranging them in the most appealing way. Make sure that the growth rings as seen from the board ends all curve in the same direction. This will help reduce warping later.

Once laid out, measure across the total face to make sure it's wider than the finished panel will be. I usually allow at least 1" extra width. Using a lumber crayon, mark the entire face with a "V" so that both lines cross all the board joints. This will help you keep the correct order and alignment during glue up.



Another tip: Before final glue up, joint matched edges together. pick up two boards, folding them together as if you were closing a book, so that the marked faces touch. Holding the boards together, run them through the jointer one time together. Lay them flat and align the edges, this should produce a perfect joint.

Once all the edges are prepared, glue and clamp the panels. I prefer to use a polyurethane glue for panels. A recent test by a Fine Woodworking magazine revealed that poly glues are not as strong as once thought. But they have several other very important features: gap filling, sandability and stainability. And they are still plenty strong enough for this application. But they are a mess to work with, so wear gloves.

Once the panels are cured, they need to be sanded. I prefer to use a wide drum or belt sander to ensure a flat, even thickness to the panel. If you don't have one, call you lock lumber supplier, they will probably run your panels through their machines for a fee.



While the panels are curing, I mill my stiles and rail. Some like to mill the end joints first, to reduce tear out. If that's you, then cut all your rails to final length first. I prefer to mill my edges first, then cut my rails to length and mill the ends.




I leave the stiles a few inches long, they'll be cut after the door is assembled.




Now, cut the panel to final size, making sure to check it for square. Then mill the profile.

Before assembly, I stain the front of the panel edges. This will ensure that no unstained areas are revealed is the panel shrinks in dryer weather.



Now it's time for the glue up. Always dry fit everything first, it's the same as measure twice, cut once. If there are any problems with fit, now is the time to discover them.

Since all the stiles are longer than needed, start by marking two line on each stile to represent where they will be cut to length. I like to mate up a pair of stiles, measure and mark them together using a square. This way I know the pair are identical.


When gluing up frame and panel doors, apply an even coat of glue to both mating surfaces, where the tongue of the rail meets the dado of the stile. Apply glue only to the stile/rail joints, not to the panels, which should be allowed to float freely. I like to install small rubber balls in the groves before the panels, to help hold them in place, this helps to keep them from moving around when they shrink, but allows them to expand.

Once glued up, clamp the doors across the width in line with both rails. Check to make sure the rails are close to in line with the cut marks you made earlier on the stiles. I tend to leave the rails about 1/16" proud for trimming later. If needed, use clamps to pull the rails together, as I have here,




Finally, check the doors for square. Since the stiles are long, measure from the inside corner of the stile/rail joints, diagonally across the panel. Both diagonals should be equal. Make adjustments as needed, then let the glue cure.

After the glue is cured, remove the clamps and trim the stiles. I like to place the door face down and use a circular saw and straight edge. Square the straight edge with one stile and cut even with the rail. Then measure and mark the finished door height to the other end, on both rails. Before cutting the second end, measure the diagonals between the corners and your marks, if they are the same, your door will be square. Make the cut and check for square again. All should be well.

Profile the outside edge if the design calls for it. Now is also a good time to bore for hinges. Finish sand everything and the door is ready to stain.