Is it my Jig, my plan, or me that is defective?

[Ryan CollinsMinkel]

I recently plunged into the world of woodworking and purchased a kreg master system to build a shelving unit that I designed in SketchUp for my son's room. I tried to do my research to limit wasted material, time and frustration. However, I am unable to make flush 90 angles with internal pockets without the screw blowing out the side of the material. Here is my setup:

Plywood: 1/2" 'Cabinet grade' Sandply purchased from Home Depot. It measures to 1/2"

Drill Guide: Set to 1/2" 

Depth Collar: 1/2" at the step 

Screws: 1" SPS-C1  Coarse Kreg Pocket-Hole Screws. Based on label on screw box.

Results: You can see in the picture, the screw blew through the wood in two spots. You can spot the metal of one of the screws.

Analysis:

1. The drill guide being set to 1/2" is to have the screw emerge from the board through its center. I have attached a cross-section picture of sample ply with bit still in the rig. It shows the bit emerging very close to the outside of the the board. I cannot lower the guide any more to force it more centered. Is my Jig defective?

2. I read in the user manual online (not provided in my master kit) that I should have used a 3/4" screw NOT a 1" screw. This was found AFTER I had purchased, cut and primed everything. My wife will not let me scrap $100 worth of wood to go back and use 3/4" plywood.  Also, Kregtools.com does not show a Coarse 3/4" screw, which is the recommendation for plywood. What should I be using?

3. How do I finish the pocket holes? I purchased the paint-grade plugs, but they are not flush with the wood, nor do they even cover the screw head. The project finish will be a clean white high gloss. How do I get a clean, flush surface?

[james wilhelm]

Ryan , just a though, in your fourth pic. try drilling your pocket hole in the board on the side where your thumb is and screw it into the board the same way it is sitting  , this may help !!   Other option is getting a micro drill guide for 1/2" material , on sale at amazon for $36.25 with free shipping !!  It should fit in your master kit !! And on your plug problem , I take and cut or sand about 1/4 " off the end that goes into the hole , at the same angle that is on the plug !!  hope this is of some help , Jim !!

[David Dean]

Sorry to tale you this but you need to go outside in with your scerws or you well have a lot of blow outs.

Like a lot of folks in the commty I went out and got a microjig and it isnt all that 1. you cant scerw from the in side out and they dont make a camlpe for it but it works great for everything else just not edge's.

And here's what james was talking about the plugs you just trim a little at a time.

[Derek Gould]

I agree with drilling from the outside in. I've built a few things with 1/2" ply, and you have to be very careful to keep everything hidden. The other thing I'd suggest is to reduce the clutch setting on your drill, to avoid over-torquing the screw and driving it in too far.

I'm pretty sure I used 1" screws with the 1/2 plywood, and had no problems. It's always a good idea to do a few test holes first to make sure you don't run into problems.

[Robert Brennan]

Ryan,

I think the members have addressed the effect you are experiencing already so we will leave it there for you to try out what suits you.

So some design tips may be of assistance:

When using the Kreg jig it great for pocket hole joints but you need to place them in the most inconspicuous position as they are a bit on the ugly side, but in their defence work well.

Plywood and just about all other composite materials are notorious for being difficult to work with so you are approaching advanced work working tasks at  a entry or beginner level.

The fact you are using 1/2"ply which is on the minim material thickness is testing every aspect of the project and your skill level to the max.

You could reduce the screw length by 1/4" but you will need to glue the joints as well, so its a trade off.

So in saying that, and the input from the other member, I (and I guess we) will be looking forward to some more of your finished work.

In closing I must comment on the professionalism of your presentation in regard to the photos cut away views and description of your experience, it certainly allowed accurate advice to correct the problem.

Regards

Robert

[Gary roofner]

Plywood  1/2 inch is not 1/2 it is 1/32 to 1/16 short.

[KregCS]

Dear Ryan,

According to the picture that you have provided, the material you are working with is a little under 1/2" thick and this is the reason that your screw does not come out in the center of your material.  Since this is undersized, you will definitely want to drill your pocket holes from the outside toward your material instead of toward the edge of your board.  This will exponentially increase the strength of your joint. 

 

You will also want to use the 3/4" screw due to the smaller thickness as well.  We only offer this in a fine thread since a coarse threaded screw would only have about 1 thread on it.  These will work fine in plywood as long as you are careful not to over-tighten them and cause your joint to strip out. 

 

Unfortunately, using just the Kreg Jig, you will be unable to plug the holes since your screw will not go deep enough to allow this.  Our normal plugs are only designed to work with 3/4"-1 & 1/4" material.  In order to plug these holes, you will need to use the Micro Drill Guide as mentioned by another member.  This will allow you to use the Micro Plugs to completely cover the pocket holes. 

 

If you have any other questions on anything, feel free to contact us and we would be more than willing to further assist you. 

[Tom Smith]

I would add one more thing that may help. I had this same problem. In the quick start guide, under "Depth Collar Adjustment", it states, and highlights one part.

"To get the right Pocket-Hole depth, you’ll have to
adjust the position of the collar on the drill bit. Place
your bit inside the Depth Setting Gauge on the Kreg
Jig®, with the step of the bit at the marking which
matches your workpiece thickness, as shown"

In your third picture you show that you are setting your collar with the mark where the flute begins. There is a small step just ahead of that, to the right in your picture. For me, backing the bit back out to be on the STEP fixed it for me. There is a picture in the manual that came in my kit which illustrates it more clearly, but I cannot find an online picture to show you.  This will make the hole not so deep.

[Wayne]

It appears that your problem lies with the wood you purchased.  If it is cabinet grade wood... the 1st pic I saw seem to be filled with a lot of particle wood (I hate that stuff).  If you feel that the value of your project is worth some form of quality... then you may be spending any were from $48.00 to $54.00 per sheet of plywood.  Or, a 3/4" thick plywood wood be of better use.  Some plywood looks good from the outside.  Its what's on the inside that you can't see.  I like to tinker but the wood I like is expensive.

[Mitchell Collinsworth]

In addition it looks as if you orient you pocket holes on the other side of the piece it won't blow out having more material to bite on. You can cut down Kreg plugs to fit with a pull saw.