In this particular case forming balsawood for an insulation wrap on a steam boiler. In simple terms the process was to soak it in hot water, wrap it into shape and then heat it up. Here though are the steps and some images to show you the finer points.
1. Soaking the Balsawood in Hot Water
The pieces of balsawood were quite small and so I just used a mug with water just boiled from the kettle.
Separate the pieces, dip them in the water and ensure they submerge.
Leave them in the hot water for a few minutes.
Be careful removing the balsawood from the hot water. Use some tweezers.
2. Wrap and Fix
I had a former for the balsa wood, the important thing is you need to consider this beforehand. You also need to work out how you will hold the wet balsawood in place.
Here it is wrapped around my boiler test piece with elastic bands holding it.
It is better to use lots of fixings or a larger area fixing and less force.
3. Dry the Balsawood
You need to leave the balsawood on the former until it is thoroughly dry. You can use heat to speed this up, but ensure the heat is uniform.
Once dry you can dismantle the parts and they will hold their shape.
4. Once Formed Cut to Shape
If you form more balsawood than you need it will allow you to overlap it and then cut it to size.
5. Check the Formed Balsawood
In this example the balsawood sits under an outer sheet of brass. Here it is all held in place with an elastic band.
The fit is good, but the final fit will have a number of fixing bands that will pull the balsawood tight into place.
6. Final Assembly
In this example the balsawood is being just held in place by the brass sheet.
However, you can fix the the balsawood with glue in the final assembly. You could also layer the balsawood and use glue between the layers. This will then form a much tougher shell of balsawood.
If the balsawood gets too wet it is likely to relax in form. Therefore, you may need to hold the balsawood in shape whilst the glue dries and if you treat the surface.
This is one simple way of forming balsawood. There are other methods and they all depend on the amount of form and complexity of shape that you want the balsawood to take. Also, note that softer balsawood will be easier to form.
Balsawood comes from the West Indian Corkwood tree (Ochroma lagapus). When selecting balsa wood it is important to consider the intended application as it varies considerably in density and hardness. Used a lot in model aircraft based on the fact that it is light, easily cut and formed along with being strong and semi-flexible.