marc: the wood whisperer is sponsored by powermatic, the gold standard since 1921. and by rockler woodworking and hardware, create with confidence. (lively jazz music) well my new split-top rouboworkbench is nearly complete, and this was one heck of a project. i had a great opportunity to practice some old skills and learn some new ones.
in fact, one of those new things i learned is the concept of tapping holes in wood, basically cutting threadsso that we can use bolts instead of using thingslike nails and screws. there are some powerfulapplications for something like this so let me show how we used it on the bench and thenwe'll cut some together. pretty much all of theleg vice components from benchcrafted attach viabolts that go into threads.
it's really a cool thingif you think about it. these are movable parts, things may break. at some point we mayneed to replace the chop. you may need to make anadjustment to the hardware. it's good to be able to take it apart. here's another example. this roller guide down hereneeds to adjust to hold the parallel guide injust the right position, so we need to make fineadjustments up and down.
having threaded bolts hereallows us to loosen things up, make the adjustment,tighten it back down and know that we're notreally doing any damage to the wood because it's in a thread. let's take a look at sometraditional ways of using hardware to hold woodpieces together and why they might not be asgood as a threaded hold. let's look at nails first.nails are pretty much a brute force way of holding things together.
a nail is driven into the wood, splitting and compressingthe fibers the whole way. over time, natural forceswill cause the wood to compress even further andeventually the two pieces will come loose because the nailhas nothing to grip on to. one step up from a nail is a screw. when you rotate the screwinto the wood it pulls itself in and essentiallythreads itself into the fibers. the good thing about screwsis they are removable,
but over the course ofyears if you loosen and tighten one you wind upwidening those threads. you may even wind updestroying the threads, which whole thing goesto poop at that point. now the star of ourshow, the threaded bolt. once the threads are cutinto the wood you could put this bolt in and outas many times as you need to and it really doesn'tdo any damage to the wood, because the bolts threadsare sized perfectly to fit
nice and smooth into the threadsthat are cut into the wood. this is perfect forapplications where you may need to loosen and tightenthis thing over and over. it's going to last much, much longer. (groovy music) all you need to make a threaded hole is a drill bit and a tap. these are basically a matched pair. you want to make surethat the drill bit clears
most of the material outand leaves just enough so that the tap can cutthreads appropriately. if you want, you can actuallybuy the tap and the bit in a set so you know youhave the perfect match pair, but typically these aresized, you can look them up, and you can make sure you get the right tap set with the right bit. and of course, you wantto make sure that the tap, the threads it winds up cutting,
are perfect for the boltthat you're going to use. because i was my hole tobe nice and straight and perfectly perpendicularto the surface i'm going to use my drill press todo the initial drilling. (drilling) now this is where the magic happens. typically you would take the tap and put it into a special tap wrench. it's basically a t-handled wrench
that gives you lots of leverage, and you can twitch this guy down and slowly but surely cut the threads. i think we can do better than that. if we take our time wecan use a power drill and get this done with quitea bit less elbow grease. i'm just going to verycarefully place the tapered tip into the hole andvery slowly start to turn. let the threads do the cutting,
you don't really have to push down. you could speed up once you get started. obviously you want yourdrill on its slowest setting. once you get going ... let's pick up the speed a little bit. now we're pretty much atthe capacity of the tap so now we can reverse the directionand slowly pull it out. you can't go too fast here, if you go too fast youwill strip everything
out and just have a nicehole, what you don't want. you're backing out these treads as if you were backing out an actual bolt. here we go. let's give it a shot. (squeaking) just as an example ijust took a scrap piece of wood and put a hole in it that's big enough to take the bolt without catching. this will serve as ourexample of something you might
want to connect when you'reputting two pieces together. kind of like our rollerbrackets for the workbench. one you get down to the bottomof the hole and your bolt starts to make contact withyour washers, you're going to find this thing gettingreal tight, real fast. that is going nowhere. check it out. just one bolt, these two pieces aretogether and this is no joke. these things are reallytight. i can't even move them.
again, one bolt. imagineif you had multiples, you would have an incredibly secure fit, and you would be able toloosen it and move this piece if you needed to.incredible possibilities. of course one alternative here would be to use threaded inserts, and i've used those in the past too. the problem is they tend to come loose, and not the threads themselves.
the threads themselves are made of metal. you basically drill a hole and drive the threaded insert into the wood. it's the method that theinsert is attached to the wood that tends tocome loose over time. i don't really think thoseare the best solution either. i think now that i knowabout this method i think i'm going to use this alot on jigs and fixtures, and any project that ihave a part that needs to
be loosened and tightenedagain, and i want to make sure that it lasts for a good long time. here's the other thingthat's great about this. these taps are very cheap,only a couple bucks a piece. and they're going to last forever because you're not drilling into metal,you're just tapping wood. you should have no problem with these taps lasting for decades. you'll probably pass themon to the next generation.
spend a few bucks, get a couple taps. let me know what you think if you include them in your project. i'd like to thank benchcrafted by the way, because they introduced meto this entire technique. i would have never thought ofdoing this in wood projects, so i'd like to thank them for that. by the way, if you're interestedin this roubo workbench build we're doing itright now in the guild.
go to woodwhispererguild.com and you can see what it's all about. we have a plan and we'regiving you just a ton, a buttload, i like that phrase, a buttload of video contentfor you to check out. that's at woodwhispererguild.com. thanks for watching.