2 1x3x8' or 1 1x6x8' ripped in half
1 lb. 2" screws (I like the 1 ¾" GRK screws. They are brass-colored and the head is decorative.)
18 1 ¼" screws (or 1 3/8" GRKs)
The dimensions in these instructions will make a coffin with inside measurements of 78" long, 22 ½" wide and 14 ½" deep. The width and depth measurements work for most people, and the length should be about four inches longer than the person is tall.
Cut the 2x2 into four 14 ½ inch long pieces and four 9 inch pieces. It's a nice touch to cut a miter on the ends of the nine inch pieces. Leave the 14 ½" pieces square.
Cut all four 1x8s into two pieces, one 78" long and one 27" long. Take two 78" pieces, put them side-by-side with the good side down and slide a 14 1/2" 2x2 under the ends. Align the ends of the 1x8s with the edge of the 2x2 and drive two or three screws through the 1x8 into the 2x2. Then screw two of the nine inch 2x2s spanning the joint between the two 1x8s and about 27" in from each end.
Here's one assembled side standing upright and the other in process.
Now screw a 27" 1x8 to the bottom end of the 2x2 on each end of one of the assembled sides (the 2x2s go on the outside of the coffin). Put the second side in place and screw through the end pieces into the 2x2. Set the other two 27" 1x8s on top of the ones you just installed and screw them into place.
The first end piece attached to a side.
One more end piece to attach.
If there is an up side and a down side to the coffin at this point, turn the assembly bottom side up. Cut three of the 1x10s into nine 27 1/2" long pieces. Screw these pieces to the bottom of the coffin running perpendicular to the length of the coffin. Let the first piece hang over the edge of the end by 1 1/2", and then put the piece on the other end in place, also with 1 ½" overhang. Put the other pieces in place and screw them in. You may need to play with it a little.
Attaching the bottom pieces.
Cut the 1x4 into three 22 ¼" pieces. Cut the remaining three 1x10s to 82 ½" long. Butt the 1x10s to one another, bottom side up. The three 1x10s will give a top that will measure a little more than 27 ¾" wide. You may cut one of the boards to a narrower width so the top is just 27 ½" wide when assembled. The 1x4s are cleats that will hold the top together. Place one cleat 2 ½" in from each end of the top, centered between the sides of the outside boards, and screw them into place using the short screws. Screw the third cleat in the middle of the top.
The top, bottom side up, being assembled.
Cut the 1x3s to 79 ½" long. These are the handles, so round the edges to make lifting the coffin comfortable. Screw the 1x3s to the 2x2s on the outside of each side of the coffin. The coffin is now ready to be sanded and decorated. Before it is used, you may want to put a piece of plastic on the inside bottom and run it a few inches up the sides and ends and spread a few inches of sawdust or wood shaving in the bottom of the coffin.
The finished product.