in this video i'll show you how to make perfect dados grooves and even lap joints without a dado set without a ruler or a measuring tape or any math at all all you need is a clever little tool called a kerf maker you can buy one like i have and there are some homemade versions online if you really don't want to buy one but they do lack some of the nice features my point is don't run away because you don't own a kerfmaker you're going to find this principle very interesting and i'm going to be really quick so stick with me for a minute while i show you a kerf maker is an adjustable tool that works both as a measuring gauge and as a stop block while you make your cuts what makes this idea so clever is it has one adjustment to account for the thickness of your table saw's blade whatever thickness that may be and another adjustment to account for the thickness of the work piece however thick that may be it's simple and it's fast and you really have to see it in action so let's start with the blade's thickness the most precise way to set that is to cut the corner off a scrap of wood if you put the cutoff back in place you can see how some wood is missing from the saw's kerf we turned it into sawdust that's what i want to measure the missing sawdust because only that will account for the blade's thickness any minor differences in any of the teeth any run out in the arbor or anything in the table saw any imperfections that may add up to a loose fitting joint so the orange portion of the tool is set to the thickness of the missing sawdust and locked in place with the orange knob if you always use that blade to cut dados and that saw you never have to change the orange setting again this would be a one-time setup what you will change from time to time between different projects is the thickness of your materials so this is set with the gray part of the tool merely by pinching the work piece inside and locking it in place with the matching grain up that is all the setup there is time to put it to work this particular kerfmaker comes with a nice metal stop block in fact it's all metal there's no plastic parts in any of it there's a magnet on the end of the stop block and there's also magnets on the end of the kerf maker tool this makes it really nice because they snap together and you can easily hold the tool in place on your miter gauge first i snap the tool in position with the orange tab pointing upward slide my work piece against the other end and make a cut then i flip the tool so the orange tab was down slide my work piece against the end and make another cut these two cuts precisely divide the boundaries of the datum all that's left is to nibble away what's left and the result is a perfect friction fit every single time i love the simplicity here's a wider work piece i just reset the gray end and i'm right back to the saw making the same two boundary cuts then nibbling away the waste in between there's no complicated setup no learning curve you can even use it with a dado set or with a router bit as long as they are narrower than the dadoes that you wish to cut if you want to add some extra room in the joint maybe it's too tight for glue then add a slip of paper to your setup and the same steps may be applied to various lap joints as well it's very clever in my opinion so i thought you might like seeing it i'll put a link to the kerfmaker below if you want to check it out see you next time at first glance you may be taken aback by the tool's stunning form or its exceptional heirloom quality but the most common phrase heard in the workshops of bridge city tool users across the world is why didn't i think of that clever ideas innovative features uncompromising quality visit bridgecitytools.com today to see for yourself
