Raised panel thickness

[Todd Laubach]

I need to build some raised panel doors that will be painted so I want to use MDF for the panels. I am reading that most panel bits are sized for 5/8" thick material unless getting one with a back cutter then you can use 3/4" (same as rail and stiles).
I want to use as thin as possible to keep the weight down. I don't care about the recess in the back and want to keep the panel flush with the stiles and rails on the front.

Could I get by with 1/2" MDF?

What is confusing to me about 5/8" material is if there is a 1/4" groove in middle of stile/rail, that would leave 1/4" above the groove on the frame. Since the panel is flat on the back and is 5/8" thick, the groove takes 1/4 with 3/8 remaining, wouldn't it sit above the frame by 1/8"?
With 1/2" material and the panel routed to a 1/4" edge, I would think the outcome would be flush with the frame.

What am I missing? Maybe the groove on those sets is not centered?

Thanks for your input,
Todd

[Mel Fulks]

Todd ,I’m not understanding all of that . If you don’t get a helpful answer , rephrase. MDF makes a lot of dust . Look for the ultra-lite type.
I don’t see any reason why you couldn’t use MDF.

[Bill Dufour]

Is mdf english or is it metric like most plywood these days?
Bill D

[Keith Vertain]

Todd, your logic is essentially spot on - except for the fact that the panel is not 1/4" at the very narrow edge, it needs to be less than that in order to fit into the slot in the rail/stile, and therefore will be right around maybe 3/16" thick at the very edge.

Note you can also make the panels using the table saw, set the blade angle at 10 degrees (or thereabouts) and set your fence to the thickness you want for the edge of the panel (say 3/16"). The blade height will be set to just enough to break out the front of the mdf, leaving you with a nice raised panel look.

Hope this helps!

[Warren Lake]

groove width will be whatever the cutter head dictates or how you set it up. Groove will be behind the profile. Panels are lower than rail and style because most shops run the doors through wide belts after assembled.

What rail and and style thickness does the cutterhead say? Show a side view of it with the profile and panel profile otherwise everyone is guessing.

[Kevin Jenness]

Groove location depends on the cutters used and where you want the panel face located. You are right that holding the panel face flush with the frame requires locating the groove off center. Production shops often produce 3/4" thick doors with only a 1/8" shoulder at the back of the panel groove. You can have a thicker shoulder by using thicker frame stock, finding a panel cutter with a lower profile or leaving the panel face proud of the frame.

[Jim Becker]

Is mdf english or is it metric like most plywood these days?
Bill D

In general, MDF is often the one kind of sheet goods that are the thickness represented.
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OP, 1/2" MDF is commonly used for your application where you want a flush front with a shadow line by rabbiting the panel such that it fits in an appropriately sized groove down the "middle" of the rails' and stiles' edges. You calculate the rabbit depth based on the location and width of your groove so that you end up with the flush look you want and tailor the reveal/shadow line groove with the width of the rabbit.

[Todd Laubach]

I like this, but need to do a raised panel to match other doors across the room.

[Jim Becker]

I like this, but need to do a raised panel to match other doors across the room.

Perhaps there's confusion with your description...I guess I misunderstood, probably taking others' comments into my head. Your actual profile is going to influence the thickness of material you need for the panel and where your groove is placed will determine the front to back position which it sounds like you will want such that the front of your panel is level with the rails/stiles to match the room. "You" have to do the calculations here to achieve what you want.

[Todd Laubach]

Thanks everyone for your input.
Attached is a picture to try and help explain my question.
If using 3/4" stock for stile and rail and 5/8" stock for panel, wouldn't the panel be 1/8" higher than the stile and rail if the panel groove was centered on the stiles/rails? (I think the picture is using 7/8" stock because it looks flush)

So my question was, could I use 1/2" mdf for the panel? I don't think I could using router bit sets, but could make my own on the table saw as suggested. The 7/8" stile and rails would also make them come out flush, but IMO I think that makes the doors a bit "chunky".
door.jpeg

[Steve Demuth]

So my question was, could I use 1/2" mdf for the panel? I don't think I could using router bit sets, but could make my own on the table saw as suggested. The 7/8" stile and rails would also make them come out flush, but IMO I think that makes the doors a bit "chunky".

Whether the panel is proud relative to the frames is a product of both the depth of the panel, and the location of the groove in which it fits in the rails and stiles. Generally, rails and stiles are cut with the groove deeper than 1/4" from the face of the rails, because 1/4" doesn't leave enough depth for the molded profile of the rails and stiles.

[Jared Sankovich]

Thanks everyone for your input.
Attached is a picture to try and help explain my question.
If using 3/4" stock for stile and rail and 5/8" stock for panel, wouldn't the panel be 1/8" higher than the stile and rail if the panel groove was centered on the stiles/rails? (I think the picture is using 7/8" stock because it looks flush)

So my question was, could I use 1/2" mdf for the panel? I don't think I could using router bit sets, but could make my own on the table saw as suggested. The 7/8" stile and rails would also make them come out flush, but IMO I think that makes the doors a bit "chunky".
door.jpeg

.187" is more typical than .250" for the distance from the groove to the back of the door. Even on thick doors (1.125") I'll put the groove closer to 0.200" than .250" I don't build doors thinner than 1" (~.980") and those get the std .187"

It's all about a deeper face mould/profile in the sticking.

I will say my panel raising heads won't cut the full profile in 1/2" stock and leave 1/4 tongue.

[Todd Laubach]

That would be great. I just was assuming it was centered, but that doesn't sound like a safe assumption.

[Jim Becker]

Where you locate the groove for the 5/8" panel will determine if it's flush or proud...as I noted previously, this is a math problem.

[Todd Laubach]

That makes sense, but I thought I was locked into the groove location by the stile bit. If I move it, won't it also change the profile?