Bending bamboo into a heart shape

[Melongo]

Hello, Im new to bamboo crafting, and i need some urgent help with making a bamboo into a heart shape.

My goal is to make it into a heart shape , no larger than the size of the palm of a hand.. does anyone know if this is possible? I have a picture of what im planning to make in the attachments (drawn).

Unfortunately, i do not know what type of bamboo i have.. i just know its thin... and its green.. but im pretty sure its painted because its pretty unrealistic plus it loses colour easily. I just purchased it at a garden shop so yeah..
the bamboo stick is around 7mm thin, and about a metre long. I think there is a tiny hole in the middle with about 3mm diameter, but i cant see through the other side clearly. =(


So far, i havent had any luck with it.. i just got a candle, and started heating the bamboo stick over it, then i start to bend it. the most i can manage to bend it is around 20 degrees, if i go any further, the stick starts to break, and the inside part just snaps.

It would be great if anyone could give me any advice, help or instructions or comments or anything on how to do all this please =).

i really need to get this done in about two weeks.. before feb 14 xD
thanks in advance fellas =D

[Mark Meckes]

Hi Melongo,
This reminds me of how bamboo sometimes grows into heart shaped pieces when cut into sections ...
Porta Bambu Servilleta
http://www.bamboocraft.net/gallery/data/534/thumbs/69Mvc-203f.jpg (http://www.bamboocraft.net/gallery/showphoto.php?photo=794&cat=500&ppuser=69)
This is made from a very select piece of a Guadua. The culm grew inwardly to produce heart-shaped pieces.
- Angel

The first issue with bending bamboo has to do with the type and quality of bamboo.
The 'green' bamboo you are using is imported bamboo, sold around the world for floristry ahd horticultural stakes and has been dyed in hot (probably near boiling) water.
I've never tried using it as I have an abundance of homegrown bamboo, but I'll guess that because of the treatment and for other reasons, that it may not be as supple for bending - more stiff and brittle when bent into a tight curve.
Ideally the best bamboo for bending is locally grown, reasonably but not over mature culms, bent either green to freshly dried, as the 'glues' that bind the fibers are still elastic and malleable.
I know there is bamboo growing around Sydney, but the question is where, and a matter of getting access to some. (before the upcoming deadline)

There are many types of bamboo and the best for bending (in the round) is if the bamboo is round (doesn't have a deep groove on one side) and has a reasonable distance between nodes, for sharper curves, because the area near the node is stiff and hardest to bend.

Another thing is that bending bamboo requires practice. And it's good to have extra material to practice with, because the best way to learn is when bending beyond the breaking point, in other words, finding the limit of bending which the bamboo will endure, and then to explore various techniques to overcome the problem of the bamboo breaking.
It is easier to bend split bamboo than round bamboo.

The important thing is your trying things out and learning about the nature of the bamboo you have to work with. Working with bamboo is a never ending process of culmparative evaluation based on the material that you have in hand.

This is an interesting challenge, to bend bamboo into a heart shape ... before 'V' day. I might just give it a go myself!

Cheers,
Mark

[Melongo]

Hey Mark, Thanks for the quick reply =D it helps me out heaps. So the bamboo i have isnt really ideal for bending? Oh and.. do you know what kind of shops would sell the bamboos that are ideal for bending? because i have no idea where to look xD

Im gonna keep trying with these till i can get my hands on some better bamboo xD. Do you have any idea what i should do to these bamboo before i use bend??
am i supposed to dip it in water to give it some moisture?
Oh and do you know i if theres anything to prevent the inside from breaking while i bend it? because when i bend it.. the surface thats inside the circle breaks, should i be using a saw or knife to but a bit of the inside off so it doesnt get too much pressure?

Thanks =D

[Melongo]

Hey, i just realised we got some bamboo growing in my own backyard LOL
but we only have a precious amount.. about 3-4 sticks lol their just the same width as the dried gardenning ones i have. Oh and their still green and growing,
the highest one is around 5 ft and the rest are rather small. and towards the bottom.. the intervals or nodes? are about 15cm appart, so i think thats alright? the rest are about 7cm apart.. their a bit closer towards the top.

Can anyone give me any instructions on what to do? because i really have a small limited amount, and cant really afford make much mistakes.
thanks guys =D

[Mark Meckes]

Unfortunately bending bamboo into defined shapes is an art, which when perfected is accomplished with speed and dexterity, but in the interim requires practice and an acceptance that breakage will occur.

BTW .. I typed - bamboo sydney - into Google search and some areas that may be worth trying to find bamboo are ...
- through a garden center ... by visiting a center they might have some growing on their property that you could harvest some small canes or know where some is growing ...
- and there were other links to locations where it is growing wild or in public gardens where they might let you harvest some ... with some sweet talking persuasion.

I see 2 main technical challenges to bending a small heart shape:

1) A heart is comprise of 2 sized curves, with the top of the heart having the tightest curve. Therefore whatever is the tightest curvature that you can make is ultimately going to determine the overall size of the heart that you will be able to make with the material you have to work with.
You can make a jig or use a round object to bend the piece around after heating the bamboo and to hold it in place until it cools and sets ...
If all else fails to get a tight bend using bamboo 'in the round', another option is to split the bamboo in half or into a strip and bend this into the desired shape. You will be able to make a much tighter bend this way.

2) A heart has 2 areas, top and bottom which comes to a point.
The only way I can think of to achieve this to a limited degree in a bend is to cut out a v-shaped notch in the bamboo, which if the bend is successful will produce a somewhat blunt tip.
Another possible method is to cross over, notch and lash one or both of the connecting points.

It is quite a reasonable challenge to attempt to bend bamboo into a simple round circle ... bending bamboo into a heart shape isn't so easy. :(

For reference, here's the Bamboo Workshop category of Bending Bamboo (http://www.bamboocraft.net/workshop/showgallery.php?cat=508) pics.

Mark

[Melongo]

Oh, i was gonna make the heart side by side, then after i make it, glue the left and right one together.
Before i cut the bamboo, id just like to know.. is it better to start trying to heat it then bend right away?
or is it better to soak it up a little in water??

[Mark Meckes]

Presoaking can help when bending dried bamboo or strips of bamboo though this procedure is more helpful to prevent the bamboo from getting burnt when applying a flame to the bamboo as it is the heat that plasticizes the bamboo and makes it more supple.

Yes, you need to bend the bamboo immediately after heating the bamboo because as the bamboo cools it stiffens up. In fact once a desired bend has been made, you can immerse the bamboo in a tub of cold water to stiffen the bend. It may be necessary to make the bend slightly tighter initially to compensate for some springback after it cools. This is where experimentation is necessary to achieve the final result, though in the case of making a heart, perfect symmetry isn't essential unless you are a perfectionist. ;)

Mark

[Melongo]

Oh okay, thank you so much!
do you know if i should heat it.. then bend it a little... then heat it again,, and soak it.. and keep repeating?
or all in one go??
and is there any other advice you can give me before i start?? thanks

[Mark Meckes]

Initially feel the 'springyness' of the piece to gauge what you're up against and to note any changes during heating.
Then heat the portion you want to bend by moving the bamboo back and forth over the flame so that the area to be bent gets evenly heated.
As you do this you will gradually feel the piece hopefully becoming more supple and will need to gauge whether more heat is needed to make the bend.
Generally the outer part of the bend needs more heat as it is this part which must 'stretch' more than the inner part of the curve.
When bending by hand it is easier to make a bend away from the end of the bamboo piece because you can hold both ends of the piece to coax the bend.
However the end can be clamped to something or inserted in a drilled hole to hold that end.
Also if you have something round to bend it around it can help to prevent the inner part of the curve from caving in.
There are various jigs one can come up which help to make the bend into a specific shape.

You mentioned using a candle to heat the bamboo which may heat smaller pieces sufficiently though it does cause carbon black to coat the bamboo.
A gas /electric stove/grill/heater can be used too, in addition to a propane torch or electric heat gun etc ...
For smaller curves I would try completing the bend before cooling it.

Mark