Best shape for big cuts?

[leatherback]

So.. I was wondering. Soon I will have to work on a 3? inch diameter chop on a beech. I intent to get this to close.

What I am now wondering.. For the final cut, what it the best shape to get a smooth transition once it heals. An angular cut, that much is clear. I however often see concave advertized. It feels that at that size, one would create a dimple and convex feels like it may create a smoother transition.

Any thoughts?

 

[sorce]

Any thoughts?

I would demand pictures, not just guesses.

Somebody has to have some pictures!

Sorce

 

[BobbyLane]

whether its a flat, sloped or concave cut, much will depend on how much growth/branches there are around the cut. that will determine the speed of healing.

 

[leatherback]

speed

I am not looking for speed. I am looking for recommendations as to which shape has the best looking endresult once healed. And I know that a cut this size on a beech might take 5+ years to heal over.

 

[BobbyLane]

I am not looking for speed. I am looking for recommendations as to which shape has the best looking endresult once healed. And I know that a cut this size on a beech might take 5+ years to heal over.

depends on how the branches are set and the trees style. a pic will help
on a broom style tree a flat cut looks and works best.
a broom of sorts, but i made the cut sloped because i knew where branches would be,

only had one branch visible on the hornbeam, so a sloped cut,

 

[Cadillactaste]

I was told to use convave...and to make an indentation in the center where the hardwood was. This was to allow for a cleaner image for the area to heal with less bulge. I've a concave and a spherical concave. But for such a large cut. You will need to just dig out the center to clean it up. Even Adam Lavigne did that with my tigerbark when he was correcting the scar that was from the hurricane and a branch fell on it and took a good branch for the structure. Though my tree has lumps and bumps. That area he wanted a nice transition for profile image.

 

[Bonsai Nut]

When the edges of the cut heal over, they will be thicker than the surrounding bark. So you simply have to plan for the increased thickness. Depending where you make the cut, having thicker growth could be a good thing, or it could leave you with an unsightly nob. So a slightly concave cut will usually leave you with a flat healed wound, while a slightly convex cut will usually leave you with a more pronounced convex healed wound. If you have good tools and a lot of patience, you can carve out a recessed convex shape that will lead to flush edges with a rounded convex shape in the middle - to better follow a round profile on the exterior of a trunk, for example.

 

[BobbyLane]

When the edges of the cut heal over, they will be thicker than the surrounding bark. So you simply have to plan for the increased thickness. Depending where you make the cut, having thicker growth could be a good thing, or it could leave you with an unsightly nob. So a slightly concave cut will usually leave you with a flat healed wound, while a slightly convex cut will usually leave you with a more pronounced convex healed wound. If you have good tools and a lot of patience, you can carve out a recessed convex shape that will lead to flush edges with a rounded convex shape in the middle - to better follow a round profile on the exterior of a trunk, for example.

with that in mind i used a termite ball to get the cut more concave to negate increased thickness.
due to location i could only get so deep with concave cutters

 

[just.wing.it]

you can carve out a recessed convex shape that will lead to flush edges

Woah, now we're getting technical!
I like it!

 

[Brian Van Fleet]

The most successful chops I have made have been made from the angle of one existing branch to another, example from @BobbyLane photo:

These heal quicker and with less dieback. You’re dealing with a beech, and they’re notoriously slow to close wounds. Obviously, make the cut so it’s only visible on the back.

 

[River's Edge]

So.. I was wondering. Soon I will have to work on a 3? inch diameter chop on a beech. I intent to get this to close.

What I am now wondering.. For the final cut, what it the best shape to get a smooth transition once it heals. An angular cut, that much is clear. I however often see concave advertized. It feels that at that size, one would create a dimple and convex feels like it may create a smoother transition.

Any thoughts?

I would recommend a slightly concave cut, the depth of the concave is usually varied based on the thickness of the bark associated with the species. I assume you are speaking of the final cut. The quality of the final product is influenced by the timing and stages of the cut as well. I for one believe that a temporary transition cut to a stub aids the tree in setting up for the final cut. The final cut is a misnomer, in that often the cut is worked on several times to facilitate the best result.
If you have access to Andrea Meriggioli's book " Bonsai maples" there is a very thorough discussion of methods and steps for refining, treating and sealing scars. Over the twelve pages of information and examples illustrated it is apparent that the shape of the cut is just one of many variables that affect the quality of the result.
Within the same chapter ( 13 ) is a smaller section devoted to improvement of trunk and scars with carving and healing of defects and poorly done scar sections.
Basically the short answer is that a concave approach is best, but there are many other variables and steps to the technique that will affect the outcome.