Tips needed with Kreg pocket holes

[carbonejim]

Read this post a few days ago

, now I'm putting together face frames and want to give feedback and ask for tips.

I'm using 3/4" cherry on rails and stiles. Drilling the pockets in the rails. The torque on my drill is very low (at 4 of 20 setting.) I'm using Kreg 1 1/4" fine tooth screws. I'm having two issues:

1: If I don't pre-drill 1/8" holes in my stiles to accept the pocket screw, the stiles will split almost everytime at the ends. 2: When I pre-drill, I think my angle has been a lilttle off which results in the faces mis-aligning. This will lead to much more planing/sanding to even them up. Should I clamp both pieces down really hard?

Any advice?

-Jim

[Robert Allison]

I always clamp the two pieces together when installing pocket screws. I have never found a system that will keep them flush if I don't. And sometimes they will still move a little, especially with predrilled holes.

[Frank Boettcher]

Are you using the face clamp and the 90 degree clamp? I've used mine to put together dozens of face frames, most of them cherry and have never had a stile split, with a torque setting of 8 on a 19.2V driver. And never had any misalignment, without any predrilling. Predrilling the holes, not only not necessary, can cause problems.

I'm truly surprised, with a .125" pilot hole that you are getting enough bite on the screw to slip the torque clutch much less to cause a split. Major diameter on the thread is only .156"

Frank

[Leon]

Make sure that the drill collar is set to the correct depth. The pilot hole should be just shy of fully penetrating the end of the rail. Pilot holes are not necessary in the mating piece. CLAMP the two pieces together with the Kreg clamp. Center the wide side of the clamp over the pocket hole side joint line. I cannot say that I have ever had a splitting problem unless the screw was less than 1/8" from the end of the wood. If your rails and stiles are 3/4" wide, this may be a problem with the larger screws. You may want to make certain that you are using a #7 or smaller diameter screw. Can you post a picture of the problem?

[carbonejim]

My stiles and rails are 1.5" wide (and 3/4" thick)

I initially put the stile and rail in a 90" clamp, but got the split issue. Now I'm face clamping the stile to the table and another face clamp on the rail. The two pieces separate while driving the screw before they pull together. Maybe I'm driving them too slowly? I might be a bit gun shy now that I split 3 stiles.

I was using some of the Irwin quick clamps - but have a Kreg Bench Clamp that might have more holding power. Funny - the picture in this link shows what I could do -- is this a hint!!

Is this the Kreg clamp that you use? Kreg Face Clamp Tonight I'll double check my drill bit stop to insure correct depth. Snap a few pics of what I am trying. I'll also try a few different techniques of driving speed, drill torque and clamping techniques.

Thanks for the tips - I'll work on my technique now that I hear that others do not need pilot holes. I agree that pilot holes are not the best scenario. I worried about holding power too, so I also glued the rail and style together.

-Jim

[Frank Boettcher]

had a split or a misalignment. See the link.

I like irwin quick clamps for a lot of things, they are prone to slip and it is hard to get them perfectly aligned for something like pocket hole work. The clamps you've shown and the 90 degree will do the job. It will make a world of difference.

Frank

[Jay Pique]

Try drilling your pocket holes near the inside of the rails so they sit further back from the end of your stiles. I pretty much use only coarse thread screws b/c the washer head is larger and they don't pull through the pocket as much. Also, it *seems* that I have more success (less splitting) when I set the clutch and drive them in as fast as I can spin them. Maybe it drills out the hole better or something. And definitely, definitely follow the clamping tips that others have posted.

Or you can just go buy a Domino.

JP

[Leon]

That should not be a problem unless the screw is too close to the end of the stile. If the screw is a good 1/4" from the end you should have no problems.

The 90 degree clamp may be the problem. It is not unusual for the pieces to slightly seperate when driving the screw and using the Kreg clamp. If your clamps do not clamp the pieces tightly together and there is by chance a gap at the joint that cannot be easily pulled shut by the screw you may split the mating piece. It is important that the joint can be pulled closed by the screw. The common Kreg clamp typically will allow some slight slippage and it's function is more to keep the bottom faces of the rails and stiles on the same plane. Let the screws pull the joint tight. Do not clamp so tight that the screws cannot pull the joint closed if there is a gap.

The Kreg bench clamp is very useful and IMHO is better than the single hand clamp. If you will notice, even the bench clamp will allow some slight movement but absolutely keeps the opposite surfaces on the same plane. When driving the screw you may still see some slight seperation when the screw penetrates the mating piece however the gap will close when the screw tightens. If the pieces cannot move you stand the chance of splitting the mating piece.

I use this one also but more often use the above clamp.

The screws by themselves make a strong joint and especially when joining edge grain to edge grain however unless you plan to disassemble the joint I would always recommend adding glue tot he mix.

[Swingman]

Among the other responses, be aware that proper stock selection can also play a role in mitigating splitting.

Go through your stockpile and try to pick stock that is less flat sawn for your stile stock. IOW, pick those pieces that have more vertical grain and you will hopefully see a reduction in splitting.

I purposely do this when buying a load of stock destined for face frames, and still have the occasional split. ... it comes with the territory, and how well you recover is the key, so don't necessarily give up on the ones that are split. If you haven't already done so, you may be surprised at how many FF's can be rescued when repaired, in situ, with yellow glue and good clamping pressure.

[carbonejim]

Everyone - thanks for the great info. I took some pics, but can't get them off the camera yet - forgot the wire to pull them off my memory card.

I've had much better luck following some of the advice. This was my process:

1: Glued both pieces

2: I used the Kreg Bench clamp to pretty strongly clamp down the two pieces. I clamped the rail and stile with about half the clamp on both pieces. I think this clamp was better than a few Irwin quick clamps because the clamping pressure was delivered directly over the pocket screw area. The stile was clamped several inches away from the pocket screw area with the multiple Irwin clamp approach.

3: I set my (18 volt) drill to a torque setting of 8.

4: I drilled the screw in at full speed, stopping when the torque clutch started clicking

Last night I had no stiles split using this process! I think the combo of the clamping pressure not on the stile above the pocket screw and slower driving of the screw caused the issue.

The cherry stock I'm using is a combo of some tight grain and flatter grain. I created pocket screws on both types of grains, but agree that a tighter grain will probably hold better because the splitting lifted the face opposed to breaking off the end grain.

The end result was the faces aligned closer than before, but I still have a little work to smooth out the joints.

I still think pocket screws are the best way to join these pieces. I love the fact that the screw pulls together the joint so I don't have to wait for the glue to dry before moving to the next joints. Wouldn't the Domino require some drying and clamping?

I'll get those pics posted ASAP - I need to fing that dang cable. Thanks for all the comments! A big help!

[Swingman]

Because I do so many FF's, I use Kreg's big steel clamping plate inlaid in a flat piece of ply. This is possibly the best investment to insure that you don't have a lot of that kind of cleanup work to do, but most would likely need to do enough on a regular basis to justify the expenditure, although it's not that much considering the time it saves.

Actually, gluing the end grain of the rails to the stiles probably doesn't give you much bang for the buck gluewise. Depending upon how you apply your FF to the cabinet casework, you may be better off not bothering to glue.

If your FF is going to be glued to the casework, and particularly if there are grooves involved, in most cases I wouldn't bother with glue.

I've got pocket hole joints on jigs that have have seen a lot of abuse that were not glued and they're still strong years later.

The Domino is "loose/floating" tenon joinery and will absolutely require high standards of glue-up to work at all.

[carbonejim]

I finally got a link between my camera's compact flash and my computer, so here are some pics of the setups. Hope this helps:

Here is my failed setup using Irwin Quick clamps:

is the setup using the Kreg Clamp: difference was the clamping pressure. A tight clamp has always been best with my pocket screws. It seems like the clamping pressure doesn't allow the rail to split. In the pics you can see that I routed a 1/8th inch rabbit to help align the face frame to the cabinet box. In one case I needed to have the rabbit on the inside of the face frame which meant the clamp wasn't providing the pressure. That rail split.

Half way done with the face frames! Thanks for the help. Hope these pics help someone else.

-Jim