Bending and Twisting using the Drill-Out technique

[Grant Bowie]

Drill Out technique to Bend and Twist at same time.
Here is a description of a technique I have been using to bend and twist some trunks on Pines. I prefer to use this technique on Pines as it is not overly invasive and does not leave huge scars. The ability to twist a trunk at the same time as you are bending actually makes it easier to do the bend in the first place.
It also makes the bend more interesting. You get a compound or complex bend instead of just a single bend in one plain.

1. Using a high speed drill or Dremel insert the drill bit into the trunk at high speed at the point that you would like to bend the tree. The hole is made on the inside of the future bend. Go about half way or slightly more and try not to poke it all the way through. Wiggle it about a bit and try not to enlarge the entry hole too much. You can pull out the bit and reinsert it through the same hole but at a much sharper angle and try and clear out some of the heartwood up and down the trunk. Test the flexibility to see if it is now more flexible. If need be you can use a larger drill bit to excavate more of the heartwood. We are trying to make the trunk flexible but not to the point of collapse.

Drill Out Technique 1.jpg

2. In Sketch 2 you can see that some of the holes will not be round but elongated. This is not a problem and the holes will callous over in a short time and no evidence will be left to see.

Drill Out Technique 2.jpg

3. Drill a series of holes where you think you might like the bends to be.

Drill Out Technique 3.jpg

4. Try to vary the numbers of holes and spacing to give a more natural look as it is where the holes have been drilled that the tree will bend the most easily and it will resist bending in areas where it has not been drilled. It is easy to place the first set of holes and the second. After that you have to have a good idea of where and what you want to bend.

Drill Out Technique 4.jpg

5. I tend to semi avoid the junctions of branches and completely avoid old knuckly bits of wood as it may splinter or break.

Drill Out Technique 5.jpg

More coming

[Grant Bowie]

6. On the Pine in the accompanying pictures I used a very broad, strong and clear grafting tape as the binding. You can use just about anything of course; Electrical tape, vet wrapping, raffia, string, rubber etc. The only advantage of the grafting tape is that it is clear and so you can see the stresses on the tree at critical points during the bend and twist

Drill Out Technique 6.jpg

7. I usually apply two layers of the tape and then another layer of something else if it needs more support.

Drill Out Technique 7.jpg

8. You must know in advance in which direction you wish to twist the tree. Place the wire on in the direction that you are intending to twist. The wire will tighten on the trunk as you rotate it so you don’t need to apply it really tight. In fact if you need to use tourniquets later to tighten up the bends or keep them in place then it can be hard to get the wire under the now tightened wire.

Drill Out Technique 8.jpg

9. Start to bend the tree and rotate in the direction you have selected.

Drill Out Technique 9.jpg

10. After bending and rotating you can thread the wire for the tourniquets. You may need a very big pair of wire benders to help pull the wire away from the trunk to slip the lighter wire underneath it. If the wire on the trunk is heavy enough and the bends are holding then you won’t need tourniquets.

Drill Out Technique 10.jpg

I hope this is clear and I am happy to discuss.

Grant

[Grant Bowie]

Tree now all wired and lower branch detached from pot 1.JPG

here is the scots pine that this article is based on.

The two trunks were long, thin and straight when I started.

Grant

[alpineart]

Hi Grant , nice tutorial , , This was a topic of discussion at the Albury Bonsai Clubs last meeting .Yes i joined a club , i considered running a thin saw blade vertical and spiral it around the trunk , then using a dove tail router bit to clear out the heartwood . After seeing this i will employ this method ,The trunk in question is 45mm at the base and 1200mm high . If i cant get the bends it will be out with the saw then carve the heart out . I was looking at the tree in question and sizing it up today .Thanks for posting . Cheers Alpine

[Grant Bowie]

Hi Grant , nice tutorial , , This was a topic of discussion at the Albury Bonsai Clubs last meeting .Yes i joined a club , i considered running a thin saw blade vertical and spiral it around the trunk , then using a dove tail router bit to clear out the heartwood . After seeing this i will employ this method ,The trunk in question is 45mm at the base and 1200mm high . If i cant get the bends it will be out with the saw then carve the heart out . I was looking at the tree in question and sizing it up today .Thanks for posting . Cheers Alpine

Its always fun when you get out the power tools on the trees but I am not sure if I would go that far; yet.

grant

[alpineart]

Hi Grant i actually watch a W.P tutorial grooving a very old pine out to about 6-8mm wide and possibly 20mm deep , then inserting a wire to aid the bend .Now thats what i call drastic ,i'm only considering a 2.5 mm skirf and hollow out the center by about 8 mm after all the centers finished its job . No doubt i will try both methods .Cheers Alpine

[Dario]

Thanks Grant, great thread...very clear and concise!
Looks great!
Cheers, Dario.

[kcpoole]

Awesome Grant thanks

Mind if i borrow soem of this for a Wiki article? I will link back to this thread as well

Ken

[Grant Bowie]

Awesome Grant thanks

Mind if i borrow soem of this for a Wiki article? I will link back to this thread as well

Ken

Sure,

no problem.

Grant

[Tony Bebb]

Nice Grant.

Very concise. Good description of this technique, and I am sure it will be well used.

Tony

[Gerard]

I have seen this method employed many times and it seems to have very few failures, the most important thing is that we do not interfere too much with the sap flow. Keeping the bark damage to a minimum is the key.

I have never seen clear grafting tape used and I like the idea very much. It can sometimes be difficult to know exactly where you have drilled the holes especially if attempting more than one bend. I need to get myself some broad grafting tape.

One thing which has not been discussed is species.

I like this method for pines and junipers.
I also like the splitting method into 2, 4 or even more but only for junipers.
But I cannot think of any deciduous species where I would be keen to do this.

Can you give us your thoughts on the drill out method for deciduous species please Grant?

[Grant Bowie]

I have seen this method employed many times and it seems to have very few failures, the most important thing is that we do not interfere too much with the sap flow. Keeping the bark damage to a minimum is the key.

I have never seen clear grafting tape used and I like the idea very much. It can sometimes be difficult to know exactly where you have drilled the holes especially if attempting more than one bend. I need to get myself some broad grafting tape.

One thing which has not been discussed is species.

I like this method for pines and junipers.
I also like the splitting method into 2, 4 or even more but only for junipers.
But I cannot think of any deciduous species where I would be keen to do this.

Can you give us your thoughts on the drill out method for deciduous species please Grant?

hi Gerard,

I think we are in agreement about everything above.

I haven't used this specificaly on deciduos trees although i have done a trunk split on a Larch(deciduous conifer).
viewtopic.php?f=129&t=5746&hilit=Larch

I suppose it could be done. It would leave less scars than an open cut. Would work on Taxodium(deciduous conifer again) and elms, ash etc. Give it a go on maples etc and see how it goes.

Anyone else out there with experience or searched the internet?

Grant

[Grant Bowie]

Oh,

and one other thing. You can always do extra drilling after the tree is wrapped. You just do the drill through the plastic.

Grant

[makro]

great Tut Grant !!

[NBPCA]

Oh, and one other other thing.

I would be very careful and probably not drill, bend and twist a decdiuous tree in the above manner.

I would be very careful and probably drill and bend a decdiuous tree however. I have certainly done some carving on an elm to cause callous to hold down a rogue branch.

Grant