Thread: Dowelling accuracy

Dontcha want to support me Silent

Well, in the sense that what you say is correct, yes. The only question is how much of a problem it really is. Traditional glues really need long grain to long grain contact as we all know, but there has been debate about whether modern glues are as dependent on it and even one guy here who tried to argue that polyurethane glue eats end grain for breakfast. So I didn't want to get into the glue argument, even though I see and accept your point and agree with it to the extent that for the way I do my woodworking - with traditional glues - it is a valid one. In my opinion. Not to put down those who use dowels. Or their friends and family.

Hi Ian,

Yes the Domino has a high capital cost but if you are doing a fair bit of commercial work and say you are edge joining table tops when you can't have the zig zag profile of the spindle moulder cutter appearing on the end grain then you have to look for an alternative.

The Domino is quite capable of referencing the board faces to a standard where one pass with a sharp No 80 cabinet scraper can be followed up by 150 or 180 grit sanding and that will get you in the direction you need to aim for. That is of course taken as a given that the boards are absolutely, flat, straight and square edged and can be pulled up to a zero visible joint with one hand only on the sash cramp.

I'm not too apologetic about my comment about the mine carpentry. Good cabinet making is about attitude and state of mind as much as skill. There's a hell of a big difference between saying " I'm going to make a good job of this" and saying " I'm going to do the very best I'm capable of with this" Over 4 decades I've managed to progress from the first to the second approach and sometimes I actually feel quite pleased with myself

Old Pete

Originally Posted by Ian Smith

Careful, you'll start a fight

Yeah, I think the nub of the problem is the drill bit and, although I've never used one, those forstener bits look the goods. The Haron bit has a centre spur but they still tend to wander when used in a hand held power drill and I can't use a drill press inside a cabinet carcass.

What I think I'll do is try to make a small jig as mic-d suggested.

I did go searching for the Dowelmax mentioned by Ron Dunn, and there are some threads on this forum, one makes a comparison with the Domino, but they are a tad expensive.

Ian

Originally Posted by mic-d

Chumley, notice I said mortise (or hole if you will)is made up of endgrain.
Cheers
Michael

Must admit I didn't notice that, my apologies - looks like there's more to grain than I thought.

Cheers,
Adam

Hi Ian

I had another thought on this.

While I do not use dowels much (drawboring aside - and here I make my own dowels), when I do I use a Stanley #59 jig, which is ideal for edges. It is very accurate, which it needs to be as dowels are quite intolerant of inaccuracy, as you have found. If I needed to place a dowel in the centre of a face, then I would need to make up a jig.

The important feature, common to all and one that has not been mentioned this far in this thread, is whether you are drilling perfectly square (perpendicular) to the face? If you are doing this freehand or with a sloppy guide, then this could account for your difficulty matching up holes/dowels.

I would make a guide out of a block of wood, using a carefully set up drill press to ensure accuracy. This is exactly how Jim Krenov does his, such as when joining a carcase.

Regards from Perth

Derek

Thanks Derek and others who responded
Bloody hell!!! I didn't mean to re-ignite the dowell/domino/M&T debate - must be the hot weather.

I am in the process of making a hardwood jig to try to solve the problem and I will persist with the dowels only because my prepared stock is too short for a tenon.
If I was independantly wealthy I might have considered a Domino but I'm a looooong way from being a commercial enterprise. Even that Dowellmax at over $500 is a bridge too far

I suspect you are right Derek. Holding a hand drill exactly vertical is a real chore and I'm sure that's part of the problem, but I also think that the Haron drill bit is not as sharp as it used to be - so I'll either have go at sharpening it or get a new one

Ian

Originally Posted by Ron Dunn

Use a good quality jig and you don't need to wobble anything.

And talking about good quality jigs, I have a special on a new Dowelmax system, fully loaded:
http://www.woodworkforums.ubeaut.com...ad.php?t=79785

Just a post-script to this thread.
I made my jig a got the job done and SWMBO's buffet progresses, but not before a bit of drama.
I figured that the Haron brad-point bit was blunt and since I had one of those el-cheapo, put it in you electric drill, clamp the whole lot to your bench, fire up your drill, and ..hope, type sharpeners, I thought I'd give it a touch up.
No joy - buggered it completely.
So, since I was off to Carbatec for some other stuff I just added a new 10mm Haron bit to my list. Got home, down to the shed with my shiny new bit, set up the jig and ...wot the hell!!
The thing had some sort of wobble mid length and there was about 2mm run-out at the brad point - nearly wrecked by lovely jig.
Back to Carbatec - very nice and helpful - and rather than exchange it for another Haron at $10 I bought a nice quality German beastie for $30.
It seems Haron - like most others these days source their stuff from China and I very much doubt if the quality of the metal in them is much above mild steel.
If there's any good to come out of the current global situation is may be that we get back to a some level of home grown quality. (I won't mention the "T" word)

Ian

Reminds me of the Neal Young song, "Piece of Crap"

Saw it on the tube
Bought it on the phone
Now you're home alone
It's a piece of crap

I tried to plug in it
I tried to turn it on
When I got it home
It was a piece of crap

I went back to the store
They gave me four more
The guy told me at the door
It's a piece of crap

Hi Ian,

When the biscuit cutter was introduced, the older tradesmen were very P.O'd as it was: "the death of skill" and any handyman could start cabinetmaking.

Back to your question, it's a simple fix.

(0) Lay out the joint how it's meant to look, and mark a line at 90° across the join with a sharp pencil to accurately locate things.
(1) Disassemble
(2) Looking now at the faces which are meant to be stuck together, draw an accurate line from the mark in (0) onto this face, at 90° to the edge.
(3) Use a marking gauge to lay out the distance of the dowel from the outside face, not the dowel pops (they can be a trifle inaccurate, but usually they're fine unless you need accuracy as in this case.)
(4) Use a sharp centrepunch to pop a starting dent for the drill into the required spot. The spur bit of the drill will start in this spot.
(5) Drill as per recommendations.

If you've taken care, you'll find that the dowels should drag the joint into position accurately.

As a final comment, you usually assemble the thing dry first then clean it up before gluing/painting. The slight misalignment can be corrected easily at this stage.

Hope that this helps,

Cheers,

eddie

Eddie,
Thanks for your comments.
I understand the mechanics of getting the dowel positioned correctly - it's just the actual "doing" that was causing me grief.

Firstly, holding the drill exactly vertical, and secondly, the drill bit tended to wander even thought it was a brad point. I solved both issues with a hardwood jig about 40mm in height done on my drill press which helped both keeping the bit vertical and preventing it from wandering.

I always dry assemble first but tell me, how do you go about correcting the "slight misalignment" you mention? Do you shave down the dowel?

Ian

Hi Ian,

The centrepop mark is the critical step - gets the point of the brad-point bit started right.

Glad you worked it out

The misalignment is corrected by removing a bit of timber from the show face as required, either sandpaper or plane, depending on finish and amount to be removed.

Cheers,

eddie