I want to put my kreg jig to good use .So I am about to start a bookcase project. How much weight can the Kreg joint/screw support ? Do I just need to put a lot of screws ? or do I need more support ? My shelves will be 3/4" furn. Gr Birch ply. 12"deep x40"long. It will have a 1x1-1/2 supporting poplar face frame.
Hi Lou - Kreg has published a set of plans for a bookcase. Follow the "download Kreg jig project plans" link down in the right column of this page. You can take a cue from those plans as to screw spacing and hence the number required for your project.
I'll be finishing up a built in bookshelf shortly. Just finishing touches. My shelves on one unit are approx 44" long x 11 3/4" deep. I used 3 screws on each end and also ran a 44"x1"x3/4" ledger across the back for support. I didn't attach a face frame as I opted to finish it differently. Right now my wife has her pictures on them but soon she will be loading them up with books. I don't anticipate having any problems with the weight as I can pull and push down on the shelves and have no flex.
So you didn't pocket screw the back of the shelf at all ? Thanks for your input.
Lou, glued pocket screws are stronger than any shelf standards or shelf pins. They will support any loads you throw at them. You will need 3 or 4 screws on each end. You can space them evenly or put a pair of screws in front and in back on either end, which I like.
The other issue is the shelf sagging. 40 inch is a little long for 3/4 plywood with heavy books. Normally the back of the book case is 1/4 plywood, so it is not used to support the shelf. I think it's better to stiffen the shelves when longer than about 30 inch. You can attach a 1x2 to the plywood shelf and it will hide the end grain too.
Lou, I used just the 3 screws on each end and the ledger holds the back of the shelf up with a couple wood screws. Here's a pic of how they turned out. My wife decided she wanted to start loading up the shelves already. They're still not quite done. My design changed after drilling the front pocket screws which were originally going to hold the face frame but I opted for a different look. Not worried about them since only a midget/dwarf/baby can see from this angle. From normal height the good side is seen on all shelves.