Arrrgh. Can't make tight joint with the kreg jig

[Shift]

I bought a Kreg Jig a couple of weeks ago, and I'm having real difficulties making a decent joint.

 

I'm trying to make a simple right angle joint that looks like: L with the pocket holes on the inside of the L.

 

But the joints are almost always ridiculously weak (I can rip them apart with my hands)  and sometimes the tip and side of the screw pokes through the end grain of the of the mating board. I'm working with 1" (actual thickeness 3/4") pine. I've checked the bit depth and collar depth a zillion times, both are set to 3/4" (using the shelf of the bit not the tip to set the collar).

 

What's strange is that I can drill three or more consecutive pocket holes on a single board, screw it to the mating board, and 1 screw might join perfectly while the other two will have problems ---- even though the bit depth, collar, depth, torque and speed of the drill never changed for any of the holes. And looking at the pockets holes, they all seem the same.

 

I'm at my wits end trying to figure out what's going on.

A weekend project that I could have just screwed and glued is becoming a real problem, and I  may just have to return the Kreg Jig ... even though I'm guessing that there must be something I'm not understanding or doing right.

 

Any advice greatly appreciated.

 

[Jay De Grandis]

Check the length of the screw penetration without the mated board. Holes have debris? Check the online screw chart to be sure you have the  right thread and length...

[Jay De Grandis]

Also try manually measuring depth of pocket w/ pencil

[Shift]

Thanks Jay.

 

Holes are vacuumed out - no sawdust.

I'm using 1 1/4" coarse screws as per the chart.

 

[Shift]

Pocket hole measured with pencil is 1 1/2"

[Shift]

Big thanks for all the details Jay.

 

I tested mine using a Canadian nickel ( so it's probably a slightly different thickness), and the tip of the bit was about 1/32" above the top of the nickel with the bit collar depth that i've using (from the guide on the jig). So that seems to be fine.

[David Roberts]

Also make sure that your torque when driving in the screws is not too strong. If you over drill the screw it will of course come out the opposite side, as well as learning the "feel" of when the screw is set properly. Sometimes with the soft pine or white board from lowes or HD strips out extremyl easily. I usually glue with those kinds of woods also.  Good luck. The Kreg has definitely opened new doors for me so don't give up.

[Shift]

Thanks David.

 

I am using a Ryobi 18-volt 2 speed drill with an adjustable torque clutch. Typically I'm using the faster, less torque setting with the adjustable clutch set to 7 or 8 out of 24 (which is what ryobi recommends with softwoods) when driving in the screws, and I've experimented with both the low and hi speed settings when drilling the holes . Should I be altering this at all? 

 

[Kim C]

Someone may have mentioned this already.  I was having this trouble for awhile.  I had checked everything but my saw.  My miter saw over the years has lost its ability to stay locked into a square cut.  Before I start cutting for Kreg joints I make some cuts on scrap to check for square and adjust if needed.  Not having a good square cut I have found greatly weakens a kreg joint for obvious reasons!

[Alex Shiells]

Hi Shift,

This is rather strange seeing that the "L" joint is probably the strongest joint you can make with the Kreg system.

Check list of things:

1. The settings on the Jig is correct. CHECK

2. The pilot hole on the piece that is being drilled is not exiting the wood. (if no then the settings are incorrect)

3. If you have to test the drilled pocket hole by driving a screw through it (nothing on the other side) you see the screw exiting in the center of the end grain? (if not then your settings are incorrect)

4. Your work piece is cut square and seats flush to the surface of the connection piece? (if you are not square and flush you will never get a good joint ever not matter the type of joining)

5. Slow down the drill. The reason being, and I think this maybe the actual cause of your problem, is that you are stripping the as the screw is cutting into the wood. Basically you are over tightening it and then the screw spins and tears out all the fibers that it is cutting into and making a clean round hole. 

6. Have you tried the same on a piece of MDF or Ply? Then you can be sure if the problem is repeatable.

 

Most important: Can you post pictures of the it all? Makes the process way easier to diagnose. 

 

I hope that this fixes everything for you and you start seeing the joys of pocket hole joinery. 

[Samurai1833]

If all the settings are correct, are you using the right screw for the material?

 

Coarse for soft-woods like pine and MDF, fine for hardwoods like oak and maple.

 

If that is not it, then you may be overdriving the screw turning it into a drill and boring out the bite.  On a scrap piece or hidden area, turn down the clutch on your drill to a much lower senstivity and work your way back up to just drive a screw completely.

 

I stop short and finish by hand with a t-driver. It takes a while but I no longer strip the sites of my work-piece.

 

If none of the above: Switch to Zig Zag "pre-gummed" papers, always good for a tight joint! 

[Shift]

Thanks Kim. All the boards are are square and flush.

[Shift]

Alex ... thanks for the detailed check list.

and Samurai for the advice ... I'm using coarse screws on pine, so no problem there.

 

I think the two of you may be right in suggesting that I'm overdriving the screw and stripping hole. I'm going to do some tests this afternoon using a much lower clutch setting and let you know how that goes.