How to make the perfect box joint jig {finger joint jig } ~ beginner woodworking DIY

howdy I'm Nate and in today's video I'm gonna show you how to make a box join jig for the table saw box joint jigs can be made so they attached to a dado sled your miter gauge or they could be their own dedicated sled in this video I'm going to be making a dedicated box joint jig for one size so that way it's easy to set up and ready to go any time you want this is the best option as long as you have room in your shop for it the first step is to cut the sled board now the measurement should be based upon your needs to be able to fit your work pieces on it as you're cutting the finger joints so go ahead and make sure that whatever pieces you plan on using will fit on whatever size of a sled you need next I'm going to be making the miter bars to fit into the miter slots and I'm gonna use a piece of 3/4 inch oak that fits snugly into the miter slot the Minor bars need to be able to fit into the miter slots without protruding at all so that way when they're attached to the sled they don't lift the sled when it's being pushed to do this I'm going to take a precise measurement and then rip a piece that is a sixteenth of an inch less than the depth of the miter gauge slot with miter bar cut I'm going to test that it slides smoothly in the miter slot as well as that it sits below the surface at all points now it's time to cut the miter bars to length I'm gonna put the sled board onto the table saw so that way I could set up a relative measurement and attach my miter bar stock to my miter gauge with this all set up I can now make my first cut and cut my first miter bar and then repeat that with the same exact length for the second miter bar now I'm going to attach the miter bars to my sled board to do that first I'm going to find the center of my board so that way my board can be centered on the table saw blade then I'm going to attach some double stick tape so that way I could stick my board down to the table saw without having a worry of it moving if you don't have double stick tape you could always use some heavy weights to keep the board from shifting around during this process the neck thing I need to do is dry out some layout lines on my sled board I'm using my combination squared to mark out the center of my miter gauge slots at this point I take one of the miter bars and slide it underneath the sled in the miter slot so that way I could start drilling holes into my miter bars through my sled I do this in a number of steps so that way I avoid drilling into my table-saw itself here I'm gonna put the hole into the sled board and transfer it into the miter bar and then remove it so that way I can add the hole all the way through the miter bar without drilling into the table saw the hole on the sled will receive a countersink so that way the screw can sit below the surface of the board at this point I'm going to put the miter bar back underneath the sled so that way I can attach it with the screw this will hold it in place while I drill the other three holes for this miter bar to ensure that it lines up perfectly with the sled and the slot after drilling these three holes the miter bar is again removed and those holes are then drilled in completely through the miter bar when all the through holes on the miter bar are complete the miter bar is put back into the miter slot and the correct orientation the first screw is then attached the other three screw holes receive their counterbore and then their screws to hold it in place and then this miter bar is done and we move on to the second miter bar and do the exact same steps with the miter bars attached I'll now remove the double stick tape and test how well the sled slides my sled slides well enough so I'll give it a passing grade next I need to make a cut into my sled with the table saw blade this cut will not go all the way across the board the cut will be used to be able to line up a fence perpendicular to the cut line I'm going to be using some construction grade 2x2 pine for my Mae support fence to keep my sled neat I'm gonna have the fence the exact same length as the sled itself the fence itself will go perpendicular to the cut line in about middle distance into the sled I'm gonna hold it down preliminarily with one clamp on one side and then I'm going to be using a square to make sure that the fence is perpendicular to the table saw cut line a clamp down the second side of the fence when I was confident that it was Square to the cut line and I added four screws to the bottom of the sled that went into the fence to hold it still one on each end and a second pair next to each miter bar away from any area in which it might contact the saw or dado blade the next thing I wanted to do is add a blade guard for the exiting blade from the fence so that way my hands would be nowhere near the spinning blade on the table saw I did this by getting some cut off wood blocks and gluing them to the back of the fence I thought it'd be paper down to ensure that I wouldn't glue it to the sled surface as that would be problematic if I needed to make any last-minute adjustments to the fence I ended up having to add a second block for the blade guard because the dado blade was cutting through the side of this one the next piece of wood I'm gonna be cutting is the backer board this board will receive the spacer and I'll go upright in order to support the pieces receiving the finger joints at this point I disconnected the table saw in order to do a blade change and put the dado stack in with the dado stack installed I went ahead and carved out the opening for the dado blade into the sled making sure not to cut too far into it to preserve my blade guard so that way I don't have a slip where I pushed the blade guard easily past the blade the next thing to do is to set the blade height and the blade height is going to be determined by the pieces of wood that you're going to be cutting finger joints into so I'm going to be using half-inch plywood most likely so I'm going to set the blade so that way it just comes up slightly higher than a half inch sheet of ply maybe 1/32 of an inch the next thing I need to do is cut the spacer hole into the backer board I'm going to put the backer board on my sled just a little bit to one side which will be the opposite side into which I want the spacer to sit so I slid it to my left because I want my spacer on the right and I'm gonna cut the spacer hole with the dado blade just as it was set in the previous clip I unlocked my table saw and changed the data blade for the standard blade with my calipers I'm gonna measure the actual opening that the dado is cutting on its width and I'm gonna cut my spacer so that it's a four thousandth of an inch less than that I'm cutting my spacer out of some oak scrap it's great to use hard wood for the spacer as it is gonna take some abuse now it's really hard to get to a thousandth of an inch accurate on width so I went ahead and did best I could and I was pretty close but I needed to shave just a little bit off and I used some sandpaper on a flat piece of melanine to take off about six thousandths of an inch in order to come up with a very close measurement I took the backer board and put the spacer into it to both check its width and to mark out its height now the height of the spacer needs to be just a little bit maybe a thirty second or less than the actual height of the opening the is done so that it'll not be lifting the backer board or the work pieces from the sled surface I failed to mention that I made my spacer longer than needed because I'm going to be using the cutoff I'm making right here later now it's time to add the spacer to the backer board notice how I cut mine a little bit too short on its height however I did not find that to be a problem with attaching it to the backer board before attaching it I did miter the top two corners this is to ease the work pieces on to it as if there are two square and rigid it might be hard to get your freshly cut finger joints to fit snugly over it it's now time to attach the spacer to the backer board I'm gonna first clamp the backer board to the sled with a piece of paper separating the spacer area from the sled the paper is to keep from accidentally gluing the spacer to the sled glue is then added to the spacer to the areas in which you want it to be glued which is the top and the two sides I went ahead and removed the glue from the end with my finger in just a minute when I realized that it shouldn't be there with the spacer all glued up properly I inserted it into the spacer hole I wiped off all the excess squeezed out and made sure that the spacer was sitting both all the way in the hole and flush with the sled it's now time to change the blade for the dado stack again now it's time to attach the backer board to the sled when attaching the backer board to the sled and what you're trying to do is accomplish the appropriate gap between the dado cut and the spacer now that gap can be equal to the width of the dado cut or it can be less if it's a little less than it should make assembly easier I'm gonna go for a target of six thousandth of an inch less than the dado cut now the dado cut is 0.6 Tuesday my spacer is point six one six and my target is point six one four I'm going to get my gap as close as I can to my target using my cutoff and then I'm going to test it so that way I could see what adjustments I need to make when testing the cut I go ahead and push my workpiece up against that spacer and I make the first cut with the dado and make a little finger and a recess that recess will go over the spacer to make my second cut and this cut will create another finger and that finger between the two cuts will be measured with the calipers I can measure the gap and see what we're hitting at we're hitting pretty close at 0.6 1 7 that's really good that's not quite three thousandths of an inch less than 0.6 to zero so I wanted to make a little shift then I go ahead and I do that shift with a feeler gauge I've got there a mm of an inch feeler gauge and I have a piece of wood here it has been cut to have a point and I need to move my spacer to the right to make the gap a little bit smaller so I'm going to go ahead and push that pointed wood block up against my spacer and I'm going to clamp that down with that clamp down and go ahead and remove the other clamp to slide the backer board and spacer over just a little bit and I'm gonna put my feelers age in and move the backer board back with a backer board back I'm going to go ahead and tighten up that clamp there to be able to hold the backer board in place as you see I had previously attached the backer board with screws to my fence so I'm not going to be able to use those screw again because they might shift the backerboard back to its original placement with both clamps on I'm gonna go ahead and go back to the table saw and do another test cut before I attach the backer board to the fence with screws I'm going to go ahead and make the two cuts so that way have a nice clean finger there in the middle to measure and just like that I had accomplished the exact gap that I would like for my jig and so I'd be able to make a point six one four wide gap it's now time for me to fully test the gapping without attaching the backer board to the fence now if you're a detail-oriented person you will have noticed that I have removed the holes from my backer board well that's because the segment about correcting the gap was shot after this so my suggestion is to do things as they are done in the order of this video where you correct the gap before attaching the backer board to your sled and not as I actually did now I just finished putting fingers into one side of this board I'm gonna go ahead and cut it in half so I can use the other half for the matching fingers so I'm referencing that first finger over the spacer and I'm doing that so that way the recess can go first on the second board adds its complimentary board so that way you have finger recessed matching up perfectly every time now that the recess is cut on to the second board I can go ahead and line it up with the spacer and continue just as a normal board would where I'm moving it over to the spacer on each recess one after another the test fit here is for the correction I made earlier and it fits together really nicely it's snug yet easy to put together when you're happy with the gapping go ahead and countersink some screws through the backer board into the fence make sure to pre-drill and counter seek before doing that if you've had to make an adjustment make sure to use new holes so that way the board doesn't revert back too the pre adjustment I added a little mark for ease of reference for the width of the finger joint I made the blade guard wider and as you see I did not cut through the board of wood so that way it becomes more difficult to push the blade into that guard area on the bottom of the board I added more information including the actual blade arrangement to use in case you have multiple dado blades and the actual specifications on the spacer and gap the last thing to do to tune up this blade now that I've written all those things out is to add some paste wax this paste wax will make this sled glide much smoother over my table-saw see a lot nicer there please subscribe to my channel if you found this video useful consider saving this video to a playlist so you can find it later and I'll see you guys next time

Channel: Nate Large - Woodworking DIY & More

Views: 1,439,427

Keywords: Woodworking, DIY, box joint gig, figner joint jig, fenger joint

Id: AT05FxUbMto

Length: 16min 3sec (963 seconds)

Published: Thu Jan 31 2019