Currently I am making a woodworking bench of my own design, currently sawing and chiseling dog holes in the front apron boards. The top will be around 2" thick, and am thinking of using four 3/4" allthreads from front to back. I know I have yakked about it with this bench before, but "should I" use them at all? There are plenty of these homemade benches that don't have them as I've seen online and in the books, if I did I would have to drill 43 holes, or maybe half that if I drill after sectional glue-ups...
My bench is one project where I felt mechanical fasteners were necessary. With the kind of abuse it gets, I couldn't convince myself that glue alone would be sufficient to hold that monster together. The top is approx. 90" x 32" x 2 1/4" thick and is held together by 5 pieces of 9/16" all thread running front to back. The 2 1/4" x6" breadboard ends are pegged in slotted holes AND lag bolted in slotted holes. I also double pegged the mortices on the base. I have no doubts this bench will be in use long after I am not! I'd suggest using the allthread if this bench is going to be an "heirloom". If it's just a temporary (only 1 lifetime or so!) bench then do what is easiest for you. I do think that 3/4" allthread is a bit extreme though. 4 pcs. of 1/2" to 5/8" would be adequate. Hey! post some pics! I'd like to see what you've got together so far. --dave
"AAvK" wrote in message news:RZ6Nf.76$123.41@fed1read09...
(Good name, BTW!) The only place I have seen this used is to support a shoulder vise (Frank Klausz bench), where there are significant forces trying to pull the boards apart. And in my bench, I have predrilled (except for the last 1/2" or so) to be able to add that in the future if needed. So far, I haven't needed it even there. On other parts of a bench have no such pulling-apart force that I can see. If your lumber is relatively well seasoned, and you are not subjecting it to huge humidity swings, I can't see what the allthread will add.
And 3/4" seems to be WAY overkill. I'm not an engineer, but what forces could you possibly be dealing with that a 3/8" or 1/2" rod wouldn't handle?
Note: Like any other, this free advice may be worth what you paid for it, so consider it only one guy's opinion.
If you're going to use "store bought" dogs, hopefully you have one to act as a pattern for the dogholes.
If you're going to make your own dogs then you can make them to fit the dogholes.
Either way, making a template and routing the dogholes on the inside of the bench frame is a lot easier, assuming the apron stock is thick enough.
Two inch solide or two 1" layers glued together? The latter will let you route dadoes in the bottom of the top layer and in the top in the bottom layer - for All Thread. Lots easier than trying to drill LONG holes through the bench top.
For the All Thread, if you go with a shoulder vise you really need 1/2" minimum All Thread through the "arm", it's spacer and the front apron to tie them together.
The top is going to expand and contract - no matter what you do. How you join the apron parts together is critical. Dovetails,without an glue, will allow for movement on one axis, but not on the others. This will allow for expansion and contraction where it's needed but limit movement where it needs limiting.
If you're using splines to to aline the core to the apron - don't use any glue. That's where the All Thread through the apron and bench top will hold them together.
Really think through the apron joinery and how the assembly will go - because the splines complicate things a bit.
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Rather than All Thread and holes of somesort throught the bench top, barrel nuts and the bolts that go with them can be used to hold the apron front and back to the bench core. Had to use one on the end of my bench that has the shoulder vise because I couldn't think of any other way to do it (bottom of this page - with a tip on doing barrel nuts)
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Yes, unless it requires drilling 24" long holes. In that case consider barrel bolts to hold the apron to the bench core.
snip Really consider dovetails for the apron. They're strong and yet accomodate movement.
another newbie a few steps ahead of you - my bench is done already.
With the notable exception of securing a shoulder vise,
I can't see why it's necessary. There is just no way that you are going to be able to point apart a lamination that is somehing like 2" by 6' of glue area.
Assuming that your side aprons are allowed to move (tightly secured in only at one point), there is no crossgrain seasonal forces to split the top.
Charlie, did you or did you not glue the dovetails? If you just glued the front dovetails and the twin tennon allowing the side aprons a shift through the unglued rear dovetails, this would allow you to glue the front and rear aprons to the main benchtop , effectively making them part if the main top.
Had you considered this approach, and if so why did you not use it?
It seems to me that this approach would eliminate bolting of the front/rear aprons.
Well that's not EXACTLY true. After I'd dry fit my original arpon it became apparent thea the shoulder vise arm to the end cap needed some beefing up. Added another piece of stock to the end cap by glueing. That made the back end of the end cap look like a half blind dovetail and doubled up the thickness of the tail of the shoulder vise through dovetail. THAT required that I deepen the pin socket on the end of the shoulder vise arm. Since everything is dry fit and the All Threads hold the apron to the benchtop core, I was able to correct this oversite relatively easily.
Some people can foresee ALL the potential shortcomings of their design. Unlike the Pope, who is infammable (malprop an attempt a humor), I'm not. If there's a way to screw up - I'll find it. Which is why I try to leave myself some options. Traditional joinery does that for me. I can dry fit things, see if they work and take them apart to fix unforeseen problems. Sort of nice to have an "undo" option.
Well yes - and no.
The bench top core is two layers of rock maple. The apron is beech. Wood moves. It moves more acrossed the grain than it does with the grain. The length of the maple and the beech will change but maybe not by the same amount. Why tempt fate? (see note about re: If there's a way to screw up - I'll find it)
I used ply splines to align the bench core top to the apron top (and the end caps). The dadoes/ grooves they fit in are a little longer than the splines. Gave me a little horizontal slop which facilitated assembly. I only needed vertical control - horizontal control wasn't important.
Basically I'm saying Don't Sweat the Small Stuff.
I have enough "challenges" getting the critical things right. When I get to where I can get the critical stuff right consisently THEN I'll work on the non-critical stuff.
Once again - yes - and no.
Now that I've used this bench for a while I'm considering splitting the top into two pieces lengthwise to permit clamping down the center of the top like a can at the aprons.
I could cut a series of slots down the middle, wide enough to accomodate a clamp head - but the core is 3" thick - rock maple. Would be a LOT easier to take things apart, rip the core then rip half of the desired gap width off each of the two sides. Glue in some spacers and put the thing back together.
OR I could get some of the clamps that go through holes n the bench top
See what I mean about leaving room for options? Glue doesn't leave much room for options. I use it when I need to and don't when I don't.
C&S wrote:
see response above re: rock maple core and beech apron.
Not sure where the "secured only at one point" point is If the apron is secured to the bench top core only at one point - say at the center of the length spline - ever have a board twist, bow or crook (see first illustation on this page)?
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Think of the All Thread as insurance - you only need it when you need it. If going with All Thread isn't a major hassle to do - why not have the insurance? Paint the washer and bolt if you don't want to see shiny metal.
I only wanted to go through the Agony and Ecstacy (sp?)of making a real woodworking bench once. But I knew and know enough to know that there's a lot I don't know. As a result, I try not to burn many bridges behind me. (Why anyone, going anywhere, would even think about burning a bridge, let alone take the time to actually do it - bridges are hard to get lit - is beyond me. OK - maybe in a war it might make sense during a "strategic advance to the rear" - but explosives are far easier and quicker)
glue alone would be sufficient to hold that monster
5 pieces of 9/16" all thread running front to back.
slotted holes. I also double pegged the mortices on
If it's just a temporary (only 1 lifetime or so!)
bit extreme though. 4 pcs. of 1/2" to 5/8" would be
far. --dave
Thanks Dave and MAN your bench is HUGE! With bread board ends it is TOO substantial! I did save the images you posted last year and the recent ones, it is awesome. I think the size of my bench and how much drilling there is to do for the allthread, can't justify it. Thanks for the expert advise tho...
Thanks Alex that all makes a lot more sense. I think the Klausz bench is practicaly a science project... in order to win a phd, that thing is 'so tech'. But where I live is known for "the best weather in the world" (as it were), the changes are mild. We are on the US southern west coast as a mild desert with rain in the winter, NBD.
Yeah they will be wood, too classic to me, I couldn't help it. Lignum Vitae with white oak springs.
The tail vise will be a double ended John Nyquist, 8/4 maple splined to the front, 47" or 48" long. The right end acts as a left jaw. It's dog holes will be 1" square, each edge 4" apart, the bench is for small work.
Not like boards are laminated one on top of the other, but rather standing up faces glued side to side. For reasons of others in this small thread I have decided no allthread. The bench is too small, and not a radical level of humidity changes occur here. I am using a Shark fine cut Ryoba, a few chisels and a Stanley 71. I do it this way to create a little tradition for myself in learning hand tools.
As above. But it is a tail vise, not a shoulder vise. It's actually "L-ed" into an end vise with one large dovetail using two LV bench screws (cheaper than...).
The front apron is all hard maple, so the spline will be the same wood. For that I will use the dado set on the table saw. If I have a #45 I would use that instead. I really cannot figure out what you mean by dovetails without glue...?
In California? Not much humidity here. It only effects "white pine" door jambs.
Can't find them big enough. I like the idea though, and I can picture it. You do mean steel cross dowels, right? Machine screws would go to them in the main core of the top? That's a bit hard to work though. For "me" that is.
Okay I will, where can I gat a good look at such an assembly?
The unglued splines will align the top of the apron to the top of the bench core - assuming you made them so they do that. So the apron will be fixed - vertically.
To hold the apron to the core I suggested barrell nuts in vertical hole from the underside of the bench so they won't show and the bolt into them through the apron and accessible from the face of the apron. They don't need to be big beefy ones - they're just holding the apron to the core, if you dovetail join the end caps to the aprons
Look at the Apron Assembly Order illustration.
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Because you're not going with a shoulder vise, the left end cap can have dovetail pins on both ends, just like the other end cap. The dovetail joint will prevent the apron from moving when clamping using dogs in the vise's moveable jaw and a dog in the bench apron. Theoretically you wouldn't even need the bench core other than to support whatever you're clamping - except to act as a back side wall for the dog hole.
So, if the aprons are barrel nut sand bolts attached to the core the apron can't move away from the core. By having the tails of the dovetails on the apron, if the core expands or contracts, the aprons can move with the core AND maintain the dovetails strenghth (sp?)
Look at Tip #2040A at the bottom of this page
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Flip the illustration over and imagine the barrel nut is in the core and the bolt goes through the apron. The bolt only needs to be maybe 3 inches long - 1" for half of the apron's 2" thickness, plus an inch in from the side of the bench core plus the diameter of the barrel nut plus a quarter to a half and inch. Note that the hole for the bolt extends beyond the barrel bolt. That gives you some slop for the location of the barrel nut.
Barrel nut and bolt layout and accurate drilling are critical. The center of the barrel cut MUST be directly in line with the centerline of the hole for the bolt. and BOTH holes must be square to the faces into which the holes will be drilled. You can make the bolt hole a little oversized to provide for a LITTLE adjustment The magnet trick will make getting the nut aligned with the bolt. easier. It's still tricky getting the nut to the right height AND the hole aiming the right way
Why go through the aggravation?
Options. If you want to make the bench shorted later - you can cut new dovetail tails on one end of the apron and put the end cap back on. If you want to replace an apron with a taller one - you can. If you want to widen the bench - you can. You'd have to make new end caps but . . . If you want to change and end vise - maybe to a Veritas Twin Screw - you can.
The thing about glue is that it's permanent. Change your mind a month or a year from now and you're screwed.
No matter how certain you are that your bench design will meet all of your needs, after you use it for three or four projects you probably will come up with at least one "If only I'd . . . when I built this thing I could've . . ."
The screw on my shoulder vise is too long and gets in may way at times. Because my aprons and end caps aren't glued together or glued to the bench core I can, when I get around to it, shorted the vise screw and either add on to its moveable jaw (the easy method) or cut it down, take some wood off it's spacer and shorted the left end cap of my bench.
Unless someone who wants to kill you is chasing you - don't burn bridges behind you.
Charlie, those are some incredibly good ideas. The first thing I pictured for barrel nuts was slots sawed in for the bolts to lay in, and screw into the barrel nuts. But drilled holes for that would allow the top to remain stronger indeed. I would have to do it on a drill press.
I WAS going to just glue-spline the apron into the front, or what you call 'the core of the top'. But I guess there will still have to be a spline, glued into either the front of the core or into the apron, the apron obviously.
In order to lengthen the bench top in the future, I would have to make a whole new apron, which incidentally is also the first dog hole strip. That would also include a longer breadboard end. A whole lot of work. Not trying to discourage myself, just a consideration.
But Charlie, if I did all gluing instead of your idea, do you really think it would be bad in the case of wood movement through the seasons of differences in humidity? I mean, it's all the same maple, including any splines... here in California we really don't have that problem drastically.
If the core, the apron and the splines are all the same wood, with the grain running in the same direction then wood movement will not be a problem.
Me, I like to have options. Say I should have enough rosewood or black walnut to replace the front and back aprons bestowed upon me . . .
OH - this is probably obvious but I'll point it out anyway The dogs in the apron point towards the end/ tail vise The dog in the moveable jaw of the end/tail vise points towards the bench. I ALMOST cut them all in the same direction.
If you have a face vise, either use the arpon as the inside jaw, or if you go with a separate wood for the inside jaw inset it so the outside face lines up with the outside face of the apron.
Some round dogholes in the face of the apron, two or three threaded, come in real handy for face clamping, board support for planing, a place to hold stock for sawing dovetails,....
OK thanks. It's merely a first bench built as a learning experience, even as my it being own design, a learning experience. I held this as a valuable principle. I don't need to go too far with it but it will have everything I can muster into it. It's just for small work.
Yes I understand. Just tonight I was sawing and chiseling, and "71-ing" half dog holes into the inside piece, or half, of the front apron. I did get them in the "right" direction. But as screw-ups go, I had already done this with every half hole in both pieces, they came out terribly badly. So I decided (as someone else suggested) to go with the 1" x 1" size and do it neatly as possible. By paying attention carefully, I only got three halves done in three hours.
Yeah the inside 'wood jaw' will be the front face of the apron! The inside 'iron jaw' will be incorporated somehow, I am cofused as to how deep it should be, the iron is about 3/8" thick, maybe a touch more. Standard US quick action type 7" x 4". It also must be spaced downwards 'til the tops are flush, or lower than that to make it deeper by at least 1"-2", and wider by 4" definitely, maybe 6".
I like the same idea and I will make differet kinds. Though you and Ken Vaughn use threaded pegs for another kind of front vise for face clamping, I like the hanging dog idea which works with the tail vise for clamping the sides of any given board to the front of the bench. It's in one of the bench books, I think the Schliening one. I do like the idea of holdfasts as well so I have two T-type steel dogs for those holes. There will be peg holes in the front, too.
Thanks for the great help and encouragement! Seriously!
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