Back to doweling jigs

[Phil Thien]

A couple of enormous real-world work assignments have wound-through, and I'm back to make good on my commitment to deliver a 1/4" doweling jig.

One thing I've learned is, a bunch of shorter 1/4" dowels, a multidimensional array if you will, is a pretty great alternative to many other forms of joinery, including larger/deeper dowels.

First, ease:  I've now standardized on 1" long dowels, so I can pretty much set the bit depth using a stop collar once, and forget it.  I don't need larger dowels or longer dowels, because I'm using MORE dowels.  And I only will need one dowel size to stock, going forward.

Second, strength:  I've been testing to destruction and it seems a lot of smaller/shorter dowels is actually stronger than fewer larger/deeper dowels.  I was hoping for almost as strong.  My best guess is that distributing the stress over a wider area of the joint is pushing the envelope on the typical failure mode (where the stock itself just fractures apart).

Third, speed:  Drilling 1/4" holes that are 1/2"-ish deep is really fast, even in challenging types of lumber.  Chips from drilling fir, for example, can be a challenge to evacuate from holes when drilling larger/deeper.  A 1/4" D 1/2" deep hole is not a problem in this regard.  It is much much faster/easier drilling twelve (12) 1/4" holes than four or five 3/8" holes that are 1" to 1-1/2" deep.

I don't know of any other doweling jig that can do anything like this, not without having to jump through quite a few hoops.  And it would be nowhere near as fast.

The astute observer will note that the fastener holes in the template are now pocketed.  With the screw heads recessed, I can use a larger drill guide block, improving perpendicularity.

I'm also using a "real" 1/4" drill bushing.  They aren't inexpensive, but will each joint needing more dowels, I figured it was worthwhile.

I'm still tweaking a couple of things.  Like, the sandpaper on my fence is scraping-up the surface of the workpieces.  I need finer-grained sandpaper.  Most joints would be sanded but as you can tell form the pics, the alignment is so good that it might take more work to get the scratches from the sandpaper out, than to flush-up the joint.

Also want to tweak a couple of the dimensions a little more, to make setting the fence maybe a little more intuitive using stuff we already have in our shops.

But here are some pics so you guys know I'm actually going to get this done.


First pic shows the jig and some 1-1/4 x 3-1/4 ("dressed 2x4") stock I use for making tool stands and workbenches.  I've got twelve dowels in this joint.  I've tested similar joints to destruction and found I need quite long lengths in order to get enough leverage to destroy the joint.
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Here is that same joint assembled.  Piston first, reference edges nicely aligned.
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My current drill guide block.  I thought of making something fancier, but this one works well and probably approximates my final design.
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A joint in some 3/4 x 1" stock and some 1-1/2" square stock.  Terrific fits.
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As you can see, the alignment is great, but you can see my scratches being left by my sandpaper.  I need to get some different (finer) sandpaper grits and see which works best.
[attachment=14229]

[jteneyck]

Phil, that looks like it has a lot of potential.  Do you plan on making more than one option?  I'm sure your test results are valid for interior applications, but I'm interested in it's application for something like an exterior door.  Traditionally, larger diameter and longer dowels are used for that application, but I have recently some Euro style doors made with what look to be an array of 3/8" dowels maybe 2" deep, much the same as you are doing.  


John

[Phil Thien]

Phil, that looks like it has a lot of potential.  Do you plan on making more than one option?  I'm sure your test results are valid for interior applications, but I'm interested in it's application for something like an exterior door.  Traditionally, larger diameter and longer dowels are used for that application, but I have recently some Euro style doors made with what look to be an array of 3/8" dowels maybe 2" deep, much the same as you are doing.  


John

I've done a 3/8" version, I don't think it would be ideal for doors, I'd think you'd want one wide enough to do a full rail width w/o repositioning.

So the question would be, how wide would that be, how thick are the doors typically, and what dowel spacing?

[jteneyck]

I've done a 3/8" version, I don't think it would be ideal for doors, I'd think you'd want one wide enough to do a full rail width w/o repositioning.

So the question would be, how wide would that be, how thick are the doors typically, and what dowel spacing?

Typical bottom rails are 8" wide, though I have made some as wide as 13".  But I don't think you need to make the jig that wide.  If you made the jig so that it can be indexed, like you do with Rockler's shelf hole jig, you should be able to maintain perfect alignment for multiple lengths.  If your jig had holes over 8" on maybe 1" centers it would cover all "standard" exterior door joints, and being able to index it would cover the rest.  For reference, exterior doors are typically 1-3/4" thick, but some are 2-1/4".  

John

[Phil Thien]

Typical bottom rails are 8" wide, though I have made some as wide as 13".  But I don't think you need to make the jig that wide.  If you made the jig so that it can be indexed, like you do with Rockler's shelf hole jig, you should be able to maintain perfect alignment for multiple lengths.  If your jig had holes over 8" on maybe 1" centers it would cover all "standard" exterior door joints, and being able to index it would cover the rest.  For reference, exterior doors are typically 1-3/4" thick, but some are 2-1/4".  

John

You know I was thinking about this some more.

I'm worried that if you put that many dowels that deep into a door, you might need some crazy hydraulic-type clamping at your disposal to get the joints to close.

[Alan S]

I wonder if something like a paint-on latex rubber would give a non-slip surface that would not mar surfaces? Maybe something like the spray on version of plasti-dip would work. I don't know if that would be a thin enough uncompressible coating to not hurt the high precision of your jig.

[Phil Thien]

I wonder if something like a paint-on latex rubber would give a non-slip surface that would not mar surfaces?  Maybe something like the spray on version of plasti-dip would work.  I don't know if that would be a thin enough uncompressible coating to not hurt the high precision of your jig.

That might work, although if there is anything that would allow me to not have to wait for something to dry, I think I might prefer that.

I was thinking just a lower-grit self-adhesive sandpaper, or even something like the friction tape from Lee Valley:

http://www.leevalley.com/us/wood/page.as...53293&ap=1

[NEILYEAG]

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Look forward to releasing this version.  I have the other one you made and would be interested in this as well.

Neil

[Phil Thien]

Look forward to releasing this version.  I have the other one you made and would be interested in this as well.

Neil

I'll get it done now, I've got some time now.

[Phil Thien]

By changing the spacing on the jig a bit, I've found that two spacer blocks are enough to get the holes centered on a variety of stocks.

For example, a 1-3/4" strip of wood will setup the fence on the jig for stock that is 1/2", 1", and 1-1/2" thick.  In that instance, the 1/2" thick stock would have a single row of holes, the 1" thick stock would accommodate two rows of holes, and the 1-1/2" thick stock would accommodate up to three rows of holes.  Of course, you don't have to use every hole position.

A 1-7/8" strip of wood will setup the fence for stock that is 3/4" or 1-1/4" thick.  In that instance, the 3/4" thick stock would have a single row of holes, and the 1-1/4" thick stock would have two rows.

There is really no need to perfectly center the holes in your stock, but it is important to get the fence parallel to the template holes, and a scrap of wood of the correct width makes this a simple procedure.  Also if your project calls for moving the fence, having a piece of wood that amounts to a setup gauge will allow one to return to a previous settings quickly.