Sizing a raised panel?

[Tom Jones III]

How do you determine the width to make your raised panels? In the past I've simply left half of the depth of the slot as empty room. For example, if there is a 10" opening with a slot 1/2" deep on either side, then I make the panel 10.5" wide leaving 1/4" open on either side.

I'm asking in general but right now the door I'm making has openings 10-3/8" wide with slots 5/8" deep each. The wood is walnut. According to the almanac the average humidity ranges from 56%-92%. Shrinkulator says this panel will range between 10.63" and 10.15" if it went from one extreme to another.

[David DeCristoforo]

I usually deduct an eighth of an inch from the length of the rail (measured from tenon end to tenon end). This has always been plenty of room for expansion.

[Chip Lindley]

I size my panel blanks to fit exactly the extreme height and width of a door from groove to groove, then raise them. After raising the panels, trim equal amount off each panel side to give expansion room. This way all horizontal and vertical fields are equal when centered in the frame. Spacers of your choice are used to keep the panel centered (spaceballs, or I have used little snips of clear plastic tubing which was on hand)

The entire width of your panel over the width of the grooves of a 10-3/8" opening with 5/8 deep grooves would be 11-5/8". Trimming 1/8" off each side should be sufficient. Your 5/8" grooves are deeper than most. Most commercial cabinet door shaper sets cut only a 3/8" groove.

[Peter Quinn]

I go flat to flat (out side edge of the sticking profile), minus 3/8" which is 3/16" on each side times two, and use 1/4" space balls. I'm working in New England where the RH goes from 28% in the winter to an easy 90% in the summer in unconditioned space, so this is pretty generous spacing. I set the tongue depth on the panels to give me 1/16" of flat before the profile begins to rise, which is important too. Doesn't matter how much space is at the bottom of the groove if your panel profile crashes into the sticking molding!

Seems to me the only door sets I have seen with a 5/8" deep tongue are 1 3/4" doors, and the tongue depth is usually 1/8" deeper than the molding, which changes my formula to flat to flat minus 1/8". Cabinet sets are typically 1/2" or 3/8" tongues, though I seem to recall the Freeborn sets running a groove set deeper than the flat on the sticking for strength. If that is the case with your set I'd measure groove bottom to groove bottom minus 3/8 for my doors if using 1/4" spacers. This leaves the spacers compressed during assembly but with plenty of room to compress further for panel expansion.

[Karl Brogger]

I subtract a 1/4" from the width of the rail, and use spaceballs.

[Steve Clardy]

I subtract a 1/4" from the width of the rail, and use spaceballs.


Ditto.......

[Charlie Plesums]

I saw a spec that said 1/4 inch space balls should be compressed to 5/32 inch during assembly, just under 50% compression. Or put another way, the panel width should be 2 * 5/32 or 5/16 less than the total rail length.

I have an excel spreadsheet to calculate the various raised door pieces, if interested, and am in the process of updating it for curve top doors. Drop me a note if you want it.

[Steve Clardy]

Yes. Spaceball website does say 5/16"

I do both, but usually a 1/4", as its easier for me to remember when I determine the panel size