Use with plywood

[R Ball]

Hey guys,

Newbie here.  I love the product (probably buying a kit tomorrow).  I am building a podium and will be attaching two pieces of 3/4" oak plywood.  Will this work well for that?  All the examples I'm seeing are of smaller pieces of wood. 

Since it's plywood, would I use the larger thread screws, or since it's hardwood, the smaller?

How much space should I put between set screws (in a 4' span)?

Thanks

[R Ball]

1 More thing:

I would like to use a router to round off the edge once completed. How much leeway do I have before I get to the screw tip? Or should this not really be a problem?

[Derek Gould]

It will work perfectly with 3/4 oak plywood. I built kitchen cabinets for my cottage using 3/4" maple plywood. Probably could have gotten away with lighter, but I know it's strong.

Use the coarse thread screws; even though the surface veneers are oak, usually the other layers will be a mix of softer woods. Kreg recommends screws 2" in from each end, and then roughly every 6".

[Nick Decker]

I'm a noob at the Kreg stuff myself, and will share my first experience with using it with plywood.

I had just received all my pocket hole stuff and just wanted to try it out. Grabbed a couple of scrap pieces of 3/4" construction grade plywood and attempted to join them into a simple right angle. Worked great except for one thing: Of the three 1 1/4" screws that I drove in, two were perfect. One poked through the opposite side just a tad. Pretty sure what happened was that the pokey screw hit a void in one of the inner plies. You'll notice the gaps sometimes in end cuts. So, the screw compressed the wood more at that point, and kinda poked through.

That said, you may not ever run into that situation with decent oak plywood.

[Derek Gould]

Good point, Nick; in my experience pulling through is usually due to one of;

1. Improper setup; the position or depth is off. With all wood, it's a good idea to measure the actual wood size. The plywood might be thiner than the nominal measurement, and a sixteenth is enough to get a screw popping through;
2. Not tightening the collar on the bit firmly enough, so that it moves. Happened to me a few times.
3. Over-torqueing the screw. I usually set the driver clutch to the lowest setting; a higher setting, especially in softer wood and plywood, can pull through more than it should.

[Don Foley]

In addition to the above suggestions; if I'm building a project using 3/4" plywood, whether faced with a hardwood veneer or not, I use 1" screws, especially if the piece is readily visible, such as a tabletop.  This provides an extra measure of safety against the screw accidentally poking through.  I also glue all my joints, which would offset any loss of holding power caused by using the shorter screw.

Hope my two cents worth helps, Don

[Tim Grace]

When working with plywood, I set the stop collar on the bit about 1/16" shy of the mark because plywood thickness is usually about 1/32" shy of the stated dimension, e.g.: 3/4" plywood is actually 23/32" thick.  I'd still use the 1-1/4" coarse screws, even though I will usually glue the joint, also.