Half Lap Joint Picture Frames

I've made several picture frames using a half lap joint instead of the usual 45 degree miter and I really like the look. Several people have asked me how I do it.   A tenoning jig on my table saw makes it pretty simple task. Here is how I make the frames:

Using 1/8" glass plate is good for pictures up to 11"x14" but plexiglass is better for larger pictures because it's lighter. I use 1/8" or 1/4" masonite fiberboard behind the glass and picture to keep it flat.

I have made a spreadsheet that allows me to enter the dimensions of the wood, frame and picture and calculate the dimensions that I need to cut.

Figures 1, 2 and 3 shows the half lap frame joint, dimensions and cutting instructions.
The spreadsheet uses the dimensions and gives instructions on cutting the pieces.
 

PRELIMINARY INSTRUCTIONS

Dimensions
The picture is 11" tall and 14" wide.  The 1/8" plate glass (or plexiglass) for the picture frame is the same size.  Because the picture frame covers the edge of the glass, the viewable area of the picture is smaller than the glass size so you may want to use a larger glass size so you won't loose as much of the picture when it's in the frame. There is a mat around my picture so I've decided that want to frame to overlap the picture/glass by 3/8" and I want to leave 1/16" gap to allow for wood movement. I'm using 4/4 red oak that is 3/4" thick and I want the frame to be 2" wide.
The spreadsheet calculates the final size of the frame will be 14-3/8" by 17-3/8".

Cutting
Rip the 3/4" oak to 2" wide, knowing we will need at least 65-1/8" in total.
Cut the top and bottom pieces to 18-1/4" in length and the two side pieces to 14-3/8" in length.
Then cut the half-lap tenon on each end of the top and bottom pieces by trimming off the back face side  3/8" x 2".
Do the same to the two side pieces, but this time, trim off the front face side.
Finally, rabbet one edge on the back face side of each pieces 3/8" x 7/16"

Glue up
Glue up each if the corners ensuring a 90 degree joint and a close tight joint.  Note: the top and bottom pieces will over hang the sides to the left and right by 7/16", this is normal.

Final trimming
Once the glue is dry, trim off the 7/16" excess overhang from the top/bottom pieces.  I sand all surfaces to remove the glue, round over the inside and outside edges with my router and then sand all surfaces smooth.
 
 
 
 
 
 


Figure 1


Figure 2


Figure 3


Spreadsheet



Click here download the Microsoft Excel Spreadsheet

 

Copyright 1999,2000,2001,2002
Fellow woodworkers can copy and use this information freely, all I ask that if you do just send me an email...I'd love to know if any else made pictures frames like this and I'd like to know what you thought and how they turned out.


© 2008 Mark Goodall