When making wide panels from solid wood, usually you'll glue several narrow boards together to make a piece wide enough. There are a couple of main reasons:
First, it's very hard to find stock that wide.
Second, even if you could find stock that wide it usually wouldn't be very flat, and it would almost certainly cup over time. By gluing up multiple narrower boards, this will all be minimized.
When you're building with solid-wood panels, it's also best to leave them free-floating rather than pinning or gluing them in. That's because the wood will expand and contract across its width as humidiy levels change. If the panel is pinned in, it will eventually crack or may even push the door frame apart. That's why solid-wood panels are generally mounted in a groove rather than in a rabbet, and why they should be slightly undersized.
I hope this information helps.
Hey Ryan, KregRep is right, you will have to do glue-ups for your center panels. You also want to leave about 1/8 of an inch less panel so it can contract and expand. Check out Infinity tools on the web, they have the best router sets for doors in my opinion, they also make ones that will work for undersized 5.2mm ply from the homecenters. As far as your lumber options, check around and find a local sawmill or molding shop to buy lumber. Most of these places can mill the lumber to the thickness you need unless you have a planer.
Ryan, both the Kreg Rep and Justin are correct in building raised panel doors. The problem with raised panel doors, as stated is the panel moving form humidity and dealing with warped lumber. Like the Kreg Rep stated the door panel will break apart the frame unless the panel is allowed to float within the frame. My method of controlling the problem is to cut the panel 1/4 inch less in width that the rail of the door. This allows 1/8 inch on each side giving the panel enough room to float without any danger of breaking apart a door frame. Because this makes the panel loose in the frame it will now be loose and will move side to side which should now be controlled to prevent rattling and also maintain its relationship of being centered within the door frame. There is an inexpensive product made that should be used to control movement. This product is called "space balls" and are 1/4 inch dia rubber balls that you fit in the the panel groove of the frame using two to three to each side depending on the door height. There is also another one that is a rubber composite called "panel aline" also known as "panel liners" that do the same thing. Some door building companies will use a couple headless pins in the top and bottom in attempt to hold the panels to prevent rattling and excessive movement however I do no recommend this as the rubber balls or strips are much better.
Something that you may have seen in doors of cabinets is the edges that show the lack of stain on the panels leaving a streak. This is usually caused by the panel floating inside the frame uncontrolled. The panel was once centered and the finish applied. During use the panel has moved and allows the unstained part of the panel to now show. You can often grasp the panel and move it back and forth. Using the space balls and or strips control this yet still allows the panel to move from humidity. On occasions you will also note a door rattle when it is closed and this too is the loose panel. The inserts will also prevent this.
The large width panel made of a single piece of lumber is subject to being un flat and even if planned flat will often become cupped when exposed to humidity. To control this I will make my glue up of multiple pieces and if possible alternate the growth rings. This is where the importance of grain matching comes into play in order to keep an attractive panel and yet insure a stable door. It is good practice to attempt to use the same board color and grain to maintain an even finish color.
A few months ago I made a slide show on making arched raised panel doors and I posted it under "my projects" section. It covers several areas of interest in building raised panel doors that you might find interesting to view. This should be the link:
Ryan, I don't use a router or a jointer to get the glue up joint tight. I use a accurate table saw with a good blade. My blade of choice is a "forrest 40 tooth woodworker II" but there are many saw blades that will give you a nice finished edge. I have found that the best edge for a glue joint is not one that is run over a jointer as the glue bites the best in a accurate cut edge from a table saw. Need more help just ask. Enjoy your work but work safely.
Ryan McAllister said:
WOW!! I knew I'd get help, but all this is awesome!! I feel like I can really do this now. Is it absolutely necessary to joint the panel strips( the edges) on the router table to get a tight glue joint? I can't wait to try this!! By the way Jay, great video, huge help!!
I love the way that members of this community jump in to help! Great job guys! you're wonderful assets to this Community, and we truly appreciate what you do.
Jay is right about Space Balls. They work great and I use them. You can also use small bits of foam backer rod, which is available in any hardware store.
Jay is also right about how much to undersize. Width is much more critical than length, as boards don't expand or contract much in length.
I'd add one more note to the discussion: I usually finish (and stain if necessary) my panels before I install them in the door frame. Since they're not being glued in, the stain/finish doesn't interfere. That way, if the panel does move, there won't be any unstained/unfinished portions that can show.