Broken Wood turning - chair component

[baileyuph]

Hopefully some in the wood end of our business will chime in.

Requirement is on a rocker with wood arms and support to the side of the seat
bottom, the wood turning is broken pretty much in the middle.

To repair, I have drilled into the two broken parts and spline across with as large dowel as possible, then touched up the finish.

Is there a better way to handle this?  

I am deeper in thought about this repair because of the precision drilling required, the center line is going to have to be right on to be able to insert a dowel into the two pieces and bring the pieces back in line.  I have a horizontal drilling machine and even so my jig holding the two pieces while drilling up into them in two setups on the machine is going to be a challenge.  I thought of gluing the two pieces back together then drilling one long hole into and across the break area and then insert the down with glue of course. That would be one hole at least on the two pieces that would line up. If I take this approach, I know I don't have a bit some 10 or 12 inches long (that specific I haven't measured the requirement).

There are a few of you people in the wood business that might have a tip. Keith "Hammer' has some good background in this, If I have gleaned correctly.

I could make a jig out of wood to hold he pieces or after they are temporarily glued back into one piece and search out the bit requirement if encouraged to go in that direction.  

To further clarify, this is all show wood, probably needless to say.

Doyle

[byhammerandhand]

Can you post a photo?

If it's in the middle of a turning, this is what I usually do:

* On one end of the break, use a drill press or horizontal boring machine (I have a Shopsmith that I set up with a chuck and a lathe center at the other end).   Drill as close to the center line as you can and head toward a detail such as a cove or bead nearby and drill at least 3/4" of an inch past it.

* Cut the piece with a narrow kerf handsaw right at the transition point in the turning.  Before you do this, make a mark spanning the cut so you can realign to the same point.

* Glue and clamp the cutoff onto the other half of the fractured spindle.   Let the glue dry.

* Go back to the drill and use the hole you drilled previously as your guide hole and drill past  the fracture point into the other part of the spindle.

* Glue up the holes and insert a dowel or dowel pin and clamp it together.  Realign your mark.

* Touch up color and/or fill as needed at the cut line.   Because it's in a transition point, it's easy to hide.

I use a similar technique on back spindles where they are broken into a slab seat.  Drill from the top down into the stub of the tenon, all the way through the bottom of the seat.  Glue the spindle back in place, then come up from the bottom using the hole you drilled before to automatically center the hole for a dowel.



If the break is more toward the end of the spindle, glue it up first and just drill into the tenon.


George Polya said the difference between a trick and a technique is that a technique is a trick used more than once.

[baileyuph]

Keith I think I understand. Yes, it would be better if the break was closer to and end of the turning, but it is probably 6 or 8 inches. The break is nasty, not a clean break following grain.

This piece of wood is the vertical, more or less, support for the level arm section it connects to (the top piece where a person's arm will rest. That is two separate pieces that have been milled out. The vertical component of the arm is a turned component primarily but does become curved wood on the end closer to the floor where it is screwed to the side of the seat. The top half is turned where it joins the level piece a person's arm rest on.

Due to the length of the two broken pieces, running a drill from one end to just past the break would require a pretty long bit. If it was shorter, the technique described could be executed much easier.  I will study what I have to work with and will keep your idea of shortening one of the components with a narrow kerf first which would shorten the drilling distance for the reinforcement dowel.

This thing is really a head scratch er. To reproduce the broken area on a wood lathe and then insert it into the broken component as a repair section is one option, that would probably require two dowel reinforcements, one for each end.

The option of dealing with the two broken components by mounting each piece, one at a time, and drilling a dowel hole will require some very precise setups on the Shop Smith. To further clarify, I would mount one broken component and drill down the center line by entering at the broken area then mount the other piece and do the same operation. Then, glue and insert the bridging downing to make a strong join and go from there with the finishing cosmetics.

What do you think of that technique?  I suppose you would suggest testing it first on some miscellaneous wood.

Is a brad point bit the best bit to use for a centerline hole?

Thanks for you input.

Doyle

[MinUph]

Sounds like your in a pickle Doyle,
  You should be able to find the center with a pin then an icepic to give you a starting point to guide the drilling. All twist drills have a tendency to travel in the hole. I would use a spadebit. Start with a small hole and work your way up gradually to the final hole size for the dowel. I personally like to leave as much of the real wood on as it gives a much larger glue area. Turning a new piece is really the best way but can be tedious.

[byhammerandhand]

Here are some photos of a demo piece that I did:

V cut simulates a fracture.



Drill through the fracture to nearest detail



Saw off at detail


Glue and clamp on stub, then let dry



Drill the other way, your holes are now aligned



glue and dowel

[baileyuph]

Excellent presentation Keith, that is the understanding I gathered from your collective posting.  

You are able, or was able to join with one dowel, a longer one. By sawing at detail and drilling into precision surfaces, the chances of the dowel alignment is higher than otherwise.

That looks like the best approach, now I have to (when back at the business) estimate how much the technique will shorten my overall piece and what I can do to account for that difference.

Thanks to Paul, I noted that you spoke from experience in your comments.

One question Keith, your twist bit, what type did you use? Also, did you free hand the drilling or jig it in your Shop Smith?

Fun stuff, wood working has become part of the business because the demand knows you can.

Anyone else?

Doyle

[byhammerandhand]

When I organized my tools into a new chest earlier this year, I was shocked at the number of drill bits that I own*.  I think my choice in this would be brad point.  One difficulty is trying to get the drill started in a jagged end.   Sometimes, I'll drill a smaller hole (1/8" or less) to create a "point" for the drill bit to hit.   I also sometimes use an awl to get a starter hole, too.   The drill bit in the photos is a "bullet point" chosen for no reason other than it was already sitting on the work table.


* Twist bits, bullet point, brad point, spade, Forstner, bell-hanger, Yankee driver, masonry, pocket hole,  auger bits,  extra long, fly cutters and hole saws.  Usually multiple sets of each.    I have a tool problem, but I can stop, anytime.

[MinUph]

* Twist bits, bullet point, brad point, spade, Forstner, bell-hanger, Yankee driver, masonry, pocket hole,  auger bits,  extra long, fly cutters and hole saws.  Usually multiple sets of each.    I have a tool problem, but I can stop, anytime.

Why stop isn't that a normal thing to have as many tools as you can fit in your shop?

[byhammerandhand]

I have a cousin that snorts brake fluid.   He says it's not an addiction because he can stop anytime he wants.


How about this video, that resembles my shop a lot?  Fast forward to 6:23 to see what I'm talking about.
http://www.youtube.com/watch?v=HkSvQlH9elM&feature=player_embedded

and this one , too
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/545848_480719598621798_1625040169_n.jpg

[gene]

I'll bet that guy in the picture knows where every single item in his shop is located.

Organization is for those who are too lazy to get up and look for things.

Maybe "organization" is like "beauty", it's in the eye of the beholder?

gene

[baileyuph]

Feedback:

Using tips from Paul and Hammer, I got it done and delivered.  In this situation I used the Shop Smith and drilled into the broken pieces in two setups.  It was challenging that way, I didn't see a detail that I could cut off and establish a hole that would allow reinforcement with a common dowel.

The rest of the good news is learning the Hammer technique.  That is one cool way of handling breaks similar to mine.  In time, that technique will be very good to know.

Paul, I drilled starting with a very mall bit and graduated up to a desired size.

Doyle