2 pocket hole questions

[kenneth fleming]

Hi,
Currently use a Castle TSM 11 tabletop pocket hole machine. Does a nice job but sometimes I get the stile bending down from the rail on a frame. If I was to put a straight edge across the rail the stile would not be flush and it would angle downwards as I move away from the joint. This does not happen often but it has and it does on a few occassions. This becomes extra painful when it is part of a cabinet run that needs stile all joined to one another. I do not feel I have any issues with the clamping as it works fine in most all other joints. Might it be a screw tightness issue that I am pulling the stile at an odd angle ? My joints are all tight and I do in most instances need to add one little twist to the screws to assure the tightness of the joint. Am I making the screws too tight ? The wood is all at 90's on all edges to the front.

Another question is when using a 1/4 x 1/4 dado in the frame to panel construction is anyone having issues using a 1 inch pocket screw with splitting because the screw is near the groove in the frame ? My panel tongue is on the inside of the cabinet and I am going to use pockets from the outside of the panels (all are hidden) to attach the frames after prefinishing all. In my testing I get a little cracking as the screw enters the frame because of the closeness to the grove. Does anyone do this and has anyone had any issues ? I know that I need to go to a 1 inch as the 1/4 deep tongue causes the pocket cutout to already be 1/4 into the frame. FYI, this is currently being tested on hard maple..

Appreciate the feedback...

[Andrew Pitonyak]

Are you sure that you fed the screw at the correct angle? I had a few issues if I do not properly seat the screw before I screw it in.

[kenneth fleming]

Are you sure that you fed the screw at the correct angle? I had a few issues if I do not properly seat the screw before I screw it in.


Hi,
Yes, the screw goes in fine...thanks

[Chris Padilla]

A couple thoughts here:

Check the screw to make sure it is straight and the head is straight..not bent.
Check to make sure there is no debris in the joint.
Finally, do things line back up if you release screw pressure? You triple-checked for squareness of the stock? :)

[kenneth fleming]

Hi Chris,
Yes, all of those things have been checked...I missed the last instance of this until after it was too late and the glue had set. So backing off the screw would have no bearing on it...

thx

[Jeff Duncan]

The machine cutting the holes should have no bearing in the frames not staying flat. If the stock is truly square and the screws go in correctly it should seat flat unless.....your end cuts are not square? I'm guessing that's where your problem is since it's intermittent:rolleyes: Remember you don't need to be off very much on that joint for it to multiply quickly over the length of a rail! Best bet is to clamp the faceframe parts down on a flat surface as you go to ensure they stay flat regardless;)

As far as the dados I only do a 1/8" deep groove just enough to keep things aligned and apply a bit of adhesive. If your doing 1/4" that's a bit deep so I'm not too surprised your getting splitting. Try using 1/8" on a cabinet and I think you'll find it's plenty deep and works without splitting. I use soft maple and 1-1/4" fine thread screws for solid wood.

good luck,
JeffD

[kenneth fleming]

Good points on both fronts Jeff....I do the 1/4 as usually I do not use pocket screws to attach the frame. In this situation the cases are large and I'm planning on dry assembly, prefinish individually pieces, then put back together. I am planning on the screws from the outside hidden panels and the hidden bottom.

thx

[Mark Bolton]

I'd say Jeff has you in the right direction. Whenever youve got a wracking in the joint, and the joint is tight on all faces, it's your cut that's the problem. If it were anything with the screw or debris you would have an open joint on one side or the other.

[Kevin Jenness]

Pocket joints are prone to misalignment due to the angle of the screw engagement- you want a flush joint, but when you drive the screw it tries to pull the rail below the stile. Clamping the two pieces tight down to a flat surface is essential. and I go to the length of clamping endways as well to prevent squirming. The Castle machine with its 6 degree angle is much better in this regard than the steeper Kreg type boring machines. As far as splitting goes, as Jeff says, minimize the groove depth and use fine thread screws. In hard woods like sugar maple or wenge sometimes it's necessary to predrill to eliminate splitting.

[Stephen Cherry]

The machine cutting the holes should have no bearing in the frames not staying flat. If the stock is truly square and the screws go in correctly it should seat flat unless.....your end cuts are not square? I'm guessing that's where your problem is since it's intermittent

This would be the first place to look.

Also, I would try to see if you can increase the depth of the pilot screw part of the cut. It seems like a short pilot hole is easier to get out of whack. This is one of the advantages of the castle machine- that the pocket and pilot are from separate cutters.

Is the clamp really holding everything flat?

[Joe Adams]

If the joint is not open on the front or the back, then the problem is with the rail cut or the stile edge. I've seen plenty of S4S stock that I had to run through the jointer and tablesaw to establish the perfect edge angles needed to make flat stile and rail panels or faceframes. Not to mention using a planer to establish uniform thickness from board to board and sometimes even on the same board. Lumber mills just aren't set up to keep everything dialed in during production so what you buy in the store may need some more work in the shop before you can actually use it.

I prefer the Castle pocket hole machine to the Kreg jig because of the lower angle. I have both. I use Kreg clamps but I also install a Festool Domino in most joints to maintain the alignment.

[Richard Coers]

Are you clamping them really tightly together when driving the screws? If there is even the slightest gap, the screw can pucker the wood inside the joint as it self drills the wood. I will occasionally use a long straight bit to drill out the screw clearance hole, so it gets a really good clamp up. Not good for production, but that is usually not the case for me.

[kenneth fleming]

Thanks again everyone for the great feedback...I did spend some time last night and found a few things. Not going too crazy on the screws seems to help. Using a faster drill to make the initial entry and then either using the clutch or slowing down and a little hand tightness at the end helped. I also did look over the "bad" on from the night before in a little more detail and I did notice a slight out of 90 on the stile. Very slight and probably it appears to of what caused it. Things went better last night and again thanks for the feedback.

[Rich Engelhardt]

Not going too crazy on the screws seems to help. Using a faster drill to make the initial entry and then either using the clutch or slowing down and a little hand tightness at the end helpedI found out that putting pocket screws in by hand the last 1/4 of the way made a lot of my alignment problems disappear.

[Rick Potter]

Snugging the screws with a driver and then hand tightening has improved my joints too.

Rick Potter