pocket screws for face frame construction

[David Zaret]

I believe the Castle pocket cutters have a very low angle compared to drill based systems. But yes, the Kreg is a good system...you just have to have things clamped down really well. Perhaps your pneumatic clamps need adjusting?

jim, funny you say that. i bought this machine at IWF a few years back, and when i was shopping for one, we went to the castle booth, knowing that the drilling angle is preferred. after 20 minutes of hanging out in the booth, right by the $6k machine i was thinking of buying, and getting blown off to a degree that's nearly shocking at IWF. so i left. Kreg seemed high quality, and they paid attention to me.

anyway -- maybe i need to check the drill depth on the machine, and my air pressures.

thanks again.

[Bruce Wrenn]

Let the screws do the work Don't try to force them in. When screw exits first piece, it has to start a new hole in second, but it's advancing forward with every turn. A thinner shank screw may help as it will be looser on hole in first piece. Are you sure you have drill bit set to correct depth? Bit should just protrude through first piece.

[Kevin Jenness]

I have found I get the best results by clamping endways as well as down across the joint.

Splitting in maple or harder woods can be eliminated by predrilling with a 1/8" aircraft drill.

I use a Castle type machine and the lower angle definitely helps with alignment, but I think you will find that clamping in both directions will work with the 10 degree Kreg angle. The key is to keep the parts from moving as the screws are driven. You might experiment with the drilling depth or with another brand of screw. I never really liked the Kreg setup which doesn't drill the pilot hole all the way through the rail, leaving it to the screw to complete that step. I think the screw may be pushing the pieces apart with that last bit of swarf.

[David Zaret]

bruce i'll definitely check the drill depth. i'm using the #7 fine threads, i believe, not the #8. i'll check my technique to ensure i'm not pushing too hard...

[John TenEyck]

Let the screws do the work Don't try to force them in. When screw exits first piece, it has to start a new hole in second, but it's advancing forward with every turn. A thinner shank screw may help as it will be looser on hole in first piece. Are you sure you have drill bit set to correct depth? Bit should just protrude through first piece.

Pocket holes with the Kreg jig do NOT break through the drilled piece (rail, in this case). If they do, it's not set up properly.

John

[Thomas McCurnin]

+1 for Kreig, but I use a dedicated Kreig clamping jig and their screws. I pay close attention to the length of the screws and the stock and run 1-2 practice pieces to see if I get any blowout. Usually with properly sized stock and Kreig screws, and not going whole hog on the driver drill, I get good, quick results.

[Rick Potter]

I have only built two kitchens with pocket screws, but seem to have good luck. All my cabinets have been red oak. I can suggest the following which works for me, and much has already been mentioned.

I have used an original Kreg jig for the first kitchen, and a Kreg electric foreman for the second. Only Kreg 1 1/4" fine thread, washer head screws.

1: Plane and sand all members to the same thickness.

2: Light glue, and clamp down to a table. I only do one joint at a time, and clamp it tight.

3: Be careful with drill depth (especially with the Foreman, as it's easy to set it too deep). The hole should not go through the end of the drilled members, and when you drive the screw through the end, it should end up pretty much in the middle.

4: Do not drive it too deep, an impact driver can easily drive it too deep, especially if you are using the regular head screws. I always use washer head for that reason. Of course you never use flat head screws which will guarantee splits. I drive mine in till it seats well, then finish it by hand with a t/handle screwdriver. This way I can feel when it is over tightened. Remember, the deeper you drill the further into the mating piece it goes, and the lower the entry point into the mating piece is.

I have been meaning to make a Kreg table, but so far I am using a sheet of melamine with two strips at a right angle screwed on to square things up. I just lay it on the workbench when needed.

Hope this helps.

[Dan Chouinard]

I started pocket hole joinery with the manual kreg jig. I quickly learned that the vise grip type of clamp supplied by kreg is not helpful. I clamp to a table with a bessey kbody and twist the knob on the clamp as hard i can. Great results in softer wood but have yet to try in maple but we are considering using maple in future paint grade cabinet projects. The part that is counter intuitive for me is the bit about not drilling pilot hole all the way thru. I learned decades ago that if a pilot hole is actually thru the wood and is larger than the screw thread and let the screw head do the holding you get much better results.

[Eric Schmid]

What Kevin is saying has been my experience. After some difficult Birch, I reworked my setup for certain woods.

For clamping, I use a Kreg right angle clamp. Push the two pieces firmly on the table and set the right angle clamp. Then for good measure I’ll clamp the faces of the two pieces down to the bench or table top. Once the first screw is in, one clamp across the face of both pieces should be sufficient. The standard double round pad Kreg clamps work well for this.

Before driving the screw try an aircraft bit as Kevin suggests. Take some care to find the angle initially. I think I cut a small angled block. You don’t need to drill the full depth of the screw in the mating piece. About half that distance should stop the splitting.

I guess I use pocket screws primarily as clamps, just ones that stay in place. The advantage may not be speed in assembly, but rather speed in moving the project along. I don’t need to wait for glue to cure and can move on to final assembly of the cabinet.

[Jim Dwight]

I don't think you have room but in cabinets I find that a domino or biscuit in the same joint as the pocket screw works well to reduce or eliminate shifting. Even a dowel would make a big difference, I think, if there is room. Pocket screw could still clamp the joint.

[Prashun Patel]

I have similar clamping issues in hard, hardwoods like maple and oak too. The issue I believe is the self drilling tip. That has to do a lot of work on harder woods. Hard woods really need to be pre-drilled for me to be consistently successful with screws; this makes pocket holes less appealing here.

So, my advice is use the pocket jig for the softer woods and dominos for the harder ones. For my money, it's not just about the speed, but the effort required to get that speed. Dominos, while requiring double the cuts of pocket screws, make the mating cuts a snap because they don't have to align perfectly if you use the sloppy switch.

[Jared Sankovich]

Castle pocket, but those are a kitchens worth (82 panels) of soft maple face frames. The top pocket centers are about 1/2" from the edge.

No splits, kreg 1.5" screws (7/8 thread engagement) pockets are set for the pilot hole to break through at the exact centerline of the 1" stock.
20210211_131746.jpg

Worst shift is about .004 to .006, on some but I intentionally over drove to ensure a gap free bead miter.
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Clamp setup
20210211_135242.jpg

[ChrisA Edwards]

Castle pocket,

Are these with the Castle 110 machine or one of the more expensive ones?

[Jared Sankovich]

Tsm-10 (porter cable licensed version) generally the same as the current Tsm-12 model. Though I added a pneumatic clamp and foot switch.

[David Zaret]

i think the domino+pocket screw for clamping is the answer. that's what i was doing prior to my theoretical change to gain speed and efficiency, but i think i'll go back to that with hardwoods.

i really like the profile and angle of the castle holes more than the kreg. wish they had cared enough at IWF to take my money.

thanks for all the help and feedback - i'll drop a wax stick in with the screws and use it, and i won't drive them as hard. good ideas.

--- dz