April 25, 2017 by Scott - Saws on Skates
Setting up the Kreg Pocket Hole Jig and using it to build DIY furniture is sooo easy! Despite that mistakes are easy to make, and trust me, I’ve made most of them! Today I’m sharing with you 9 pocket hole mistakes you don’t want to make.
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If you have been following for a bit you know I use my Kreg Jig for nearly every DIY furniture project I build. Over the years I’ve had a lot of pocket hole successes, but I’ve also made a few pocket hole mistakes along the way. Today I’m sharing those mistakes with you, so you don’t make them too!
9 Pocket Hole Mistakes You Don’t Want to Make
Kreg Jig Overview
First, let’s review what a Kreg Jig does and how to properly set it up for building DIY furniture, Then, we’ll look at the pocket hole mistakes we want to avoid. The jig uses preset holes to drill angled pocket holes in a piece of wood. A pocket screw, specifically designed for use with pocket holes draws the two pieces of wood together.
The most common joints made with the Kreg Jig are a butt joint or edge joint. A butt joint, joins the end of one piece of wood to the edge of another piece of wood. Common uses for butt joints are frames for side assemblies and door frames. An edge joint joins the edges of two boards. Common uses for edge joints are panels and furniture tops.
Kreg Jig Setup
Step 1 – Set the Drill Guide
The first step to using the Kreg Jig is to adjust the drill guide to the thickness of your board. If your board is 1-1/2″, set the jig for 1-1/2″. For this example, our board is 3/4”, so we’ll set the drill guide to 3/4”.
Step 2 – Set the Drill
The next step is to set the drill depth. Again, you’ll want to match the drill depth to the thickness of your board. For this example, our board is 3/4”. Loosen the collar with an Allen key and move the shoulder of the drill bit (or the bottom of the stepped area of the drill bit) to correspond with the 3/4” mark and tighten the collar.
Step 3 – Drill Pocket Holes
Next clamp the board in the jig to correspond with the appropriate drill holes. Chuck the drill bit in your drill and insert the drill bit into the guide block until it hits the wood. Slightly raise the drill bit and bring the drill up to full speed. Then gently lower the bit into the wood and start drilling the pocket hole. Keep drilling until the collar on the drill bit contacts the drill guide.
Pro Tip: For wood that is 1-1/2” wide, center the wood between holes B and C, and drill in holes B and C. For wood that is 2-1/2” wide, center the wood between holes A and B, and drill in holes A and B. Wood that is 3-1/2” wide, center the wood between holes A and C, an drill in holes A and C.
For all other widths of wood, make sure your pocket holes are set in a minimum of 3/4” from the edge to avoid possibly cracking the wood.
Avoid End Grain
You should only drill pocket holes into the ends of a board. Let’s say we are building the side assembly for the patio garden cabinet. The pocket holes should be drilled into the rails (horizontal pieces) not the stiles (vertical pieces).
The reason we don’t want to drill pocket holes into the edge of a board (vertical piece or stile) and screw into end grain (horizontal piece or rail) is because this would not create a strong joint. The grain of wood runs the length of the board. The end of the board is referred to as end grain. Think of the wood grain or wood fibers like a box of drinking straws. Imagine driving a screw into the end of a box of drinking straws. What would happen to the screw? That’s right, it would just spin around in the ends of the straws. Screwing into end grain does not create a strong joint.
There’s an exception to every rule, so there is a time when it’s OK to drill pocket holes into the edge of board and that’s when you are edge joining wood for table tops, etc. This joint works because the screw is driving through the edge of the wood and makes a strong joint.
Change Setup for Different Wood Thicknesses
Many furniture projects use different thicknesses of wood. It’s important to change the drill guide and the collar on the drill bit match the thickness of the wood you’re drilling pocket holes into.
Let’s say you’re drilling pocket holes into a 2×4. You’ll set the drill guide to 1-1/2″ and drill bit collar to 1-1/2″. Then let’s say after you drill the pocket holes into the 2×4 you need to drill pocket holes into 1×4 and you do that without changing the drill guide and drill bit collar. Well, you’ll drill all the way through the end of the board. Not Good! And yes, I have done this on more than one occasion!
How can you prevent this pocket hole mistake from happening? If I’m batch drilling pocket holes, I may use one of my 5 Unexpected Uses for Painter’s Tape tips and label the parts that require different depths of pocket holes.
Set Bit Shallower for Plywood
Plywood, like 3/4″ plywood is actually little thinner than 3/4″. So if you set your drill guide to 3/4″ and drill bit collar to 3/4″, then attach the two pieces of plywood with a pocket screw, the screw will actually poke through the edge of the plywood. Exposed screws are not an attractive look for DIY furniture! Yup, I’ve made this mistake too when I was building the Mid-Century Modern nightstand.
To avoid screws protruding through the edges of your plywood furniture projects set the drill guide to the thickness of the plywood, so for our example, set the drill guide to 3/4″. Then set the drill bit collar, so it’s shallower than the thickness of the wood. For our example set the drill guide between the 1/2″ and 3/4″ mark.
Replace Worn Bits
I use my Kreg Jig to drill pocket holes for nearly every furniture project I build. It only makes sense eventually the drill bit would become worn. It’s important to know the signs of a worn drill bit because worn bits drill more slowly, get hot quickly and produce a “fuzzy”, jagged looking pocket hole.
A jagged pocket hole is a particular concern if you’re going to use a pocket hole plug cutter to fill the pocket holes with plugs. With a crisp, clean pocket hole you can place the plug in the pocket hole, sand the plug flush with the surrounding wood and the pocket hole will virtually disappear. With a jagged pocket hole you can place the plug in the pocket hole, sand the plug flush with the surrounding wood, but edges of the pocket hole will still appear jagged. It’s time to replace your pocket hole drill bit if your pocket holes look fuzzy or jagged.
Use Wood Glue
Pocket hole joints don’t require wood glue, but that doesn’t mean you shouldn’t use glue when assembling your furniture projects. When a pocket screw is screwed through an angled pocket hole it draws the two pieces of wood together tightly. The pocket holes make a strong joint, but it doesn’t take into account the wood itself. Wood is a living thing.
Wait, did I just say wood is a living thing?! Well, not exactly living, but it is hygroscopic. Wait, did I just say hygroscopic – what’s that? Simply put, hygroscopic means it absorbs moisture from the air. Wood is constantly absorbing and giving off moisture, just as it would when it was alive. Remember earlier how I described wood like a box of drinking straws. When the drinking straws, ummm wood, fills with moisture it swells and gets bigger. When it loses moisture it shrinks and gets smaller. If you build a project when it’s humid, you may notice when the air is drier that some of the joints don’t fit as well as it did when there was more moisture in the air.
I’ve noticed this joint issue when edge joining tops for furniture projects. I built my air conditioner dresser in the summer when it was humid, but I didn’t edge glue the top pieces. The top looked great in the summer, but in the cooler months the joints of the top just ever so slightly pulled away from each other. And the edge of one of the pieces even started to slightly curl up.
Can you stop wood movement? The short answer, NO! But you can help reduce some of these issues by gluing the joints. If I glued the top of the air conditioner dresser it wouldn’t be moving like it does. Why didn’t I glue it? Well, I knew I wanted to stain the piece and regular glue doesn’t accept stain.
Almost all of us have had a finish ruined by glue squeeze out. The glue squeezed out, we stained the piece and the glue prevented the stain from soaking into the wood. What we’re left with is what looks like a big bleach stain on our project. Regular glue just isn’t stainable. Since then I found Elmer’s Wood Glue Max. This glue creates a strong bond, is stainable and now the only glue I use for my furniture projects! Pocket holes create a strong, lasting joint, but that joint is made better by adding wood glue.
By now we know how the pocket hole joint works, right? A pocket screw is screwed through an angled pocket hole and the screw draws the two pieces of wood tightly together. Despite this, you still need to use clamps to properly align the joint before attaching it with pocket screws.
Don’t try to properly align the joints with your hands. You’ll end up with glue all over your hands (you did use glue, right?) and you’ll likely end up with misaligned joints. Nothing beats the mechanical advantage of a clamp. Your joints will be stronger and your furniture projects will look more professional.
Specifically designed pocket hole clamps are available, but in my How to Clamp Your Project Like a Pro I described that I prefer to use an assortment of bar clamps. This way I can layout the entire piece, get all of the joints the way I want them, tighten the clamps and attach with pocket screws. Use clamps when you build and the look of your furniture will go from amateur to professional.
Use Pocket Hole Screws
Pocket screws are specifically designed to work with pocket holes. Pocket screws have threads only on the lower portion, while the upper portion, or shank is not threaded. This design allows the shank of the pocket screw to slide through the pocket hole and pull the joint tight. Unlike pocket screws, regular screws have threads along the entire length. A regular screw won’t slide through a pocket hole. The threads may not only crack the board with the pocket hole, but it might not pull the other board tight, yielding in an ill fitting joint. Use only Kreg brand pocket screws or another authentic pocket screw by another brand.
Pocket screws are available in two varieties, coarse and fine. Coarse pocket screws are used for soft woods like pine and plywood. Fine pocket screws are used for hardwoods like oak and maple.
Use the Correct Length Pocket Screw
Always use the correct length pocket screw for the pocket hole you have drilled. Using a pocket screw that is too short won’t connect the boards together and using pocket screws that are too long could drive the screw through the edge of the other piece. Check out the pocket hole screw guide below to be sure you’re using the right pocket screws for your project.
Pro Tip: When I use different length screws for a furniture project I will sometimes write lightly in pencil next to the pocket the length of screw I need to use. Other times I will use painter’s tape to write a note of the length of screw I need to use.
Avoid Over Tightening
The pocket holes can easily be stripped, so it’s important to set the clutch on your drill to a low setting – my DEWALT drill works well on 3. When the drill meets a certain amount of resistance, the clutch prevents the drill from driving the screw any further and prevents stripping the pocket hole.
Pro Tip: Over tightening a pocket screw is just one way a pocket hole can become stripped. Another way a pocket hole can become stripped is if you remove a pocket screw and then reattach it. Fixing a stripped pocket hole is as easy as grabbing some wood glue and heading to the kitchen for some toothpicks.
Bonus Tip – Make Your Pocket Holes Virtually Disappear
The Kreg Pocket Hole Plug Cutter will take your furniture building to the next level! The plug cutter makes plugs to fill pocket holes. The plugs are cut from leftover scrap wood from your project, so the plugs will exactly match the wood color and wood grain of your project.
The plugs are glued into the pocket holes and then sanded flush. With a pocket hole plug cutter, your pocket holes virtually disappear and you’ll make your DIY projects look more professional. This a “gotta have it” tool for the DIYer! Check out my plug cutter setup tips and video!
I hope reading about my pocket hole mistakes will help you avoid making mistakes of your own. Do you have any pocket hole tips? Please share them in the comments.
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