What am I doing wrong.

[David C]

What am I doing wrong. Got the brake on my drill set light and all of my screws are coming through the back side. Attaching 3/4 ply to 3/4 ply and using 1 1/4 course screws. HELP!!!

[Jeff Bumgarner]

I'm far from an expert, but the only time this has happened to me is when I changed to another size material without re-adjusting the set collar on the drill bit.  Take a look at the depth setting on the drill bit and I will bet you will find your set a little too deep.  Hope this helps.

[David C]

Joined them the same way and no issues. Can't believe a 1/16th would do this. Thinking about using 1" and glue.

[David C]

Jeff,
Sorry , here is the 1st part of the post. Checked the collar 4 times, all good. Ply is 1/32 thinner than true 3/4 stock. So between the 2 pieces a 1/16th. Can't believe that was it but joined 2 pieces of 3/4 pine the same way with no issues.

[KregRep]

David, you might want to double-check that you aren't over-driving the screws. Are you using the clutch on your drill? If so, what setting are you using? I usually start at a setting around 4 in plywood. Depending on the plywood, it's possible that the screws are crushing the plies as they seat into the pocket. That causes them to drive too deep. Inexpensive plywood and sheathing plywood can be especially problematic. Usually sanded ply or hardwood/cabinet-grade ply have tougher materials that don't crush as easily.

You could back down to 1" screws and still get good holding power. Or, you could try backing the drill guide block up one setting to 5/8". 

KregRep

[roy smith]

Hi David,

just another thought, and i have done this by mistake before is driving the screw at a higher speed than needed. this prevented the torque driver to stop the screw as desired. 

Roy

[Russ Haynes]

+1 to KregRep's suggestion and +1 to Roy's also.  I routinely set my bit collar a little shy of the mark when screwing plywood, just to leave a little extra material in the piece that houses the screwhead.  The Kreg screws are pretty powerful and plywood can crack at the edges.  The heads of the Kreg screws really exert a lot of force toward the joint, so having a little more material for the head to exert force on can prvent cracking at the edges, especially if there's a void there.  The other thing I do with plywood is glue the joint too, using two applications of glue on the "end grain," the first to fill the endgrain and any voids, and the second application to stick the two pieces together.  

If you're using crappy plywood, it probably has voids in it between the layers.  When a screw goes through one of these voids, it compresses the plywood around the void, causing the material to wind up thinner than it should be, in addition to the mill cheating you out of 1/32" of thickness as it is (which is BS, I agree).  The alternative in the future is to stay away from bad plywood except for shop and garage projects.  It's much better to spend some extra money and buy the mdf-core veneer ply from your hardwood dealer or solid veneer core ply.

[David C]

Thanks to all for the help. Went with the 1" screws and glue. The ply was 3/4 oak ply from Lowes and upon further inspection it looks like voids in the ply was the issue. Wow they sure don't make plywood like they u

[David C]

Used to!!!

[Jim Gentry]

David, I have set my stop exactly several time s and the same thing happened. I moved my collar down and it stopped. If I have already drilled several holes I simply switch to 1" screws for that board. Good luck.

[SFlorida]

Not to change the subject but how can u tell the difference between the 2 plywood's? I'm building a closet and need 3/4 plywood but unsure what to get. I'm not a wood expert so any help  or info would be great. Im

Russ Haynes said:

+1 to KregRep's suggestion and +1 to Roy's also.  I routinely set my bit collar a little shy of the mark when screwing plywood, just to leave a little extra material in the piece that houses the screwhead.  The Kreg screws are pretty powerful and plywood can crack at the edges.  The heads of the Kreg screws really exert a lot of force toward the joint, so having a little more material for the head to exert force on can prvent cracking at the edges, especially if there's a void there.  The other thing I do with plywood is glue the joint too, using two applications of glue on the "end grain," the first to fill the endgrain and any voids, and the second application to stick the two pieces together.  

If you're using crappy plywood, it probably has voids in it between the layers.  When a screw goes through one of these voids, it compresses the plywood around the void, causing the material to wind up thinner than it should be, in addition to the mill cheating you out of 1/32" of thickness as it is (which is BS, I agree).  The alternative in the future is to stay away from bad plywood except for shop and garage projects.  It's much better to spend some extra money and buy the mdf-core veneer ply from your hardwood dealer or solid veneer core ply.

 

[Russ Haynes]

The best way to tell is where you buy it.  If you have a hardwood dealer nearby, I recommend going to see him/her for your sheet goods just like you do for solid lumber.  It's usually higher quality and with a wider selection than the big orange or big blue store.  Here's an article from Popular Woodworking you should check out also.  I prefer MDF core plywood for furniture because it is very stable and a little cheaper than solid ply.  Good luck!