Drawboring

[Derek Cohen]

I have added a second pictorial to the Mortice-and-Tenon primer: Drawboring.

The link is here: http://www.inthewoodshop.com/Furniture/Drawboring.html

Regards from Perth

Derek

[Jeff Skory]

Nice tutorial Derek. As always, your articles are a pleasure to read.

[Eric Brown]

Nice tutorial. Some questions.

1. Did you insert the drawbore pin from only one side?
2. Was it the pin insertion side?
3. Did you try to drive the pins with light or heavy hits?
4. Have you ever used wax to make driving easier?
5. If the joint needs redone or repaired, do you recommend either pounding out the pin or drilling?
6. Was the bit for your brace make the same sized hole as the dowel?
(Some bits are slightly oversized)
7. When the drill bit broke into the mortise, did you go back and clean it up somehow or did you use a filler in the mortise?

Thanks Derek.

Eric

[Derek Cohen]

Good questions, Eric ...

1. Did you insert the drawbore pin from only one side?
2. Was it the pin insertion side?

yes and yes

3. Did you try to drive the pins with light or heavy hits?

light-moderate hits are all that are necessary

4. Have you ever used wax to make driving easier?

No. Not necessary.

5. If the joint needs redone or repaired, do you recommend either pounding out the pin or drilling?

You can knock out the pin

6. Was the bit for your brace make the same sized hole as the dowel?
(Some bits are slightly oversized)

mine was a good match in size

7. When the drill bit broke into the mortise, did you go back and clean it up somehow or did you use a filler in the mortise?

I have compared the breakout of a brace/auger, eggbeater and power drills with bradpoints. The brace and eggbeater created much the same amount of breakout inside the mortice, with the power drill (and higher speed) the least. How much? This can vary per wood type. If you are concerned, add a blank into the mortice. I mostly get a few splinters and just remove them.

Regards from Perth

Derek

[Jeff Considine]

Great tutorial, as always. Thank you for posting.

One quick question, is there any advantage to lining up the end grain of the dowel so it runs with the grain of the stile? I thought I read somewhere that was a good thing to do, but other than cosmetics I can't see a reason to do it.

Thanks again.

Jeff

[Derek Cohen]

Jeff

I must admit that this has never occurred to me to do. I doubt that it would add anything to the strength of the joint.

Regards from Perth

Derek

[Bob Glenn]

Do you use glue in the joint? If not, why not? Thanks

[Derek Cohen]

Hi Bob

The use of glue is optional.

A drawbored joint is pulled together tightly and the pin creates a strong mechanical connection. The advantage of this is that gaps in less-than-perfect joints are removed and any potential expansion of gaps (due to moisture) is minimised. You can use glue for a permanent joint, but it is not necessary as the internal tension of the pin will hold the joint together.

Regards from Perth

Derek

[Chris Friesen]

You can use glue for a permanent joint, but it is not necessary as the internal tension of the pin will hold the joint together.

Note of course that there *is* internal tension, and so you need to make sure that the tension is not so high that it blows out the end of the tenon or splits out the edge of the mortised piece.

[Jeff Skory]

Great tutorial, as always. Thank you for posting.

One quick question, is there any advantage to lining up the end grain of the dowel so it runs with the grain of the stile? I thought I read somewhere that was a good thing to do, but other than cosmetics I can't see a reason to do it.

Thanks again.

Jeff

Where I have seen this mentioned is when using large dowels (e.g. 1"). The reason for lining the dowel grain perpendicular to the surface grain is so that if the dowel expands it will not split the surface wood. I made use of this technique for a sawbench I built.

[harry strasil]

Draw boring originated with timber framing using green wood to compensate for the shrinkage when drying, I don't drawbore very often in dry wood and if I do I don't drill the hole off very much and just taper the end of the peg like the old timers did.
my 2 cents

[James Baker SD]

What keeps the joint from separating after you remove the steel drawbore pin and before you insert the wooden dowel?

James

[Rob Fisher]

What keeps the joint from separating after you remove the steel drawbore pin and before you insert the wooden dowel?

James

Nothing. The drawbore just allows you to test fit the joint, to make sure its fitting properly. If you didn't use a drawbore pin you would have to put the dowel in and set the joint to see how it fit. Getting the dowel back out of the joint, if it needs adjustments, is much more difficult than removing the tapered drawbore. Test with a drawbore pin, finish with dowel.

Rob

[James Baker SD]

Makes sense, thanks.

James

[Paul Davis]

Or, if the tenon is wide enough for a double drawbore, as is sometimes the case, leave the pin in one of the holes while driving the peg through the other.

[Andy Pedler]

I have a question about making your own drawbore pins. I read the article by Chris Schwartz about making your own drawbore pins and picked up the punch and alignment set from Sears that he recommended. I have some nice walnut to use for the handles.

Question is, how important is the step where he suggests heating up the metal punch with a torch prior to pounding it into the handle? The article states that this is to char the wood as the handle is pushed into the hexagonal top of the punch and prevent the wood handle from splitting. Since the hole drilled for the handle is round and the top of the punch is a hexagon, the punch is biting into the wood as you go.

I don't own a torch like that and I'm wondering if I can accomplish the same thing without one. Any ideas?

Andy - Newark, CA

[Harlan Barnhart]

I don't own a torch like that and I'm wondering if I can accomplish the same thing without one. Any ideas?

Andy - Newark, CA

Holding it over a gas stove top burner works fine. I makes a surprisingly strong bond. I used maple for the handle and there is no way that punch is ever coming out.