Finger joints

[jeff oldham]

Well I got to watching some you tube videos on making finger joints and I thought I would try it...it looked simple enough watching the videos and making the jig....I have worked all morning trying to dial the jig in to have nice fitting joints like I seen on you tube...I even made 2 jigs thinking I might have been off some....but according to the video I did everything right....but I can't seem to get a tight joint regardless of what I do.....the joints are always sloppy I actually thought I would have had more trouble getting the joints to line up but that wasn't the case...lol...any thoughts would help..getting ready to throw the towel in..lol

[Andrew Hughes]

To me it looks like you didn't add in the thickness of the blade. Don't give up you'll get it

[glenn bradley]

Right, I see you have two blades and those are giving you a specific kerf width. the key should be this same width and the distance from the blade to the key should also be this dimension. A dial caliper is your friend.

[Mel Fulks]

I think it's easier to lay out fingers that are tapered in order to make a permanent joint; then bandsaw them. But perhaps I misunderstood and you want to make a hinge.

[Dave Cav]

I've made lots of box joint jigs, but recently I got an Incra iBox jig, which makes box joints just about foolproof. However, it's limited to fingers about 7/8" deep, and last month I needed to make a bench with fingers about 1 1/8", so I had to cobble up a quick jig. I actually got the joints to fit on the first try with scrap and had the bench rails cut out in short order. I used the two outside plates of my Freud dado jig to make the cuts, and was careful about making the spacing key exactly the right width, and getting the placement correct. It just takes practice and attention to detail.

This is one of the better tutorials I've seen on making a box joint jig. I reviewed it before I made mine because I hadn't built one in a number of years.

https://woodworking.formeremortals.n...box-joint-jig/

20180501_163741.jpg

[Alan Schwabacher]

Your joint is loose, which means you need to move the jig so the key moves away from the blade by the amount of the gap. If they were too tight, you'd move the key closer to the gap. If they were uneven, it would mean the key is not held firmly enough. That is assuming the key was correctly cut to fit perfectly into the kerf before making the jig.

It helps if you make a longer piece from which you cut the key. Then you can correctly set the jig position by putting its key against the longer piece, while the other side of that piece is against the blade, spanning the teeth of the blade front to back.

[Charles Lent]

I've made a lot of boxes with "box joint" corners, which is what you are trying to make. To me "Finger Joints" have tapered pins and are used to join boards end to end to make longer boards. What you are trying to make are "Box Joints", not "finger Joints", where the pins are not tapered. Our woodworking trade media has been mixing these terms quite frequently, causing significant confusion to those trying to understand the difference between these two types of joints.

At one time I had 8 different shop made box joint jigs in my shop, each for making a different size box joint. Some worked very well and some were marginally acceptable. Then I saw a demonstration of a new and yet to be announced, box joint jig. It was the prototype for the Incra I-Box jig. It impressed me so much that I bought one of the first ones to be available for sale. That jig has changed the way that I make box joints and all of my shop made box joint jigs became firewood.

The Incra I-Box jig is easy to set up. As you turn the adjustment knob to change the joint size, both the pin and space width change together with the one adjustment. You just set it for the kerf width of your blade and make one test cut to be sure that it is set correctly, and then make your box joints. I was once told that "you can't cut box joints in plywood", but most of my boxes made recently have been made from Baltic Birch plywood and they go together perfectly. Attached are a couple of photos to show this. These were made with my I-Box jig on my Unisaw using a Freud SBOX8 blade set. The I-Box jig also has a sacrificial strip as part of the jig. You position this strip to an unused position after you have completed the jig and blade height adjustments and just before you begin cutting your box joints. It minimizes chipping and splintering of the cuts. I can get perfect fitting box joints of any width from 1/8" to about 1" wide with the I-Box jig.

The blade that you use is important too. I have the Freud SBOX8 blade set, which is designed for making 1/4" and 3/8" joints with perfectly flat bottom cuts. There are now several other blade manufacturers making this same style box joint blade set. For 1/8" box joints I'm using a Freud ripping blade with an FTG (Flat Tooth Ground) profile. For box joints larger than these blades can make I use a stacked dado blade set and although the resulting cuts don't have perfectly flat bottoms, they aren't as noticeable in these larger joints. Most of the box joints that I make have been with the Freud SBOX8 blade set.

I am not financially connected in any way to Incra, the I-Box jig inventor, or Freud. I'm just a very satisfied customer.

Charley

[Nick Decker]

Agreed on the I-Box jig, amazingly useful tool.

[Bill Space]

Well, you guys convinced me!

When I get back home in a couple weeks I plan on ordering one. Looks very useful and well made!

Related to that other thread, I consider this a blessing, not a curse...

(Not the first time I have bought something after reading unbiased, favorable reports here )

Bill

[Mike Manning]

I did my first box joints last year and they turned out great. I made seven drawer pullouts using box joints with 1/2" Baltic Birch. Even the trial and error ones that I tossed were pretty good. Check out William Ng's video for making a box joint jig. He's very good at explaining exactly what you need to do and why. Good luck!

Here's what they looked like after I installed them in my wife's vanity.

IMG_4039.jpg

[Nick Decker]

Bill, there's a vid posted on You Tube called "i-Box Master" which is, I think, the same that comes on the DVD with the i-Box. Covers setup and use very well.

[Bill Space]

Nick,

I got interested and watched a bunch of videos today including that one. Thanks for the pointer.

In case anyone is interested in this product, here is a link to a short video (About 6 min) that shows pretty well how the unit is set up and used for basic operations.

https://www.youtube.com/watch?v=VK4JYV2YZbA

Looks like a great product.

Bill

[Robert Engel]

The size of the registration pin and the offset are both based on the blade width.

If the gap is too wide, the gap between the registration pin and the blade is too small.

Check William Ng's YouTube video on box joints.

For me the Incra jig was too fiddly until I figured out an easier way. After the jig is set, do a test cut and measure the "tenon" and the gap between two tenons with a micrometer, then adjust the distance between the pin and blade so the tenon is 5 or 6 thou less than gap. This eliminates the need to to repetitive test cuts.

[Mike Manning]

Jeff,
I doubt you've got any play in your sled but if you do and you don't use a consistent approach to pushing your sled when making cuts that can also cause problems. Don't ask me how I know this.

Mike