This is my bow saw hot wire. It is almost an exact copy of a old Stro-jig.
The bow saw is made from a product that is no longer available. The pipe was flawed and was prone to burst. That is also why I have to dig up the slab in my work shop. It burst wile I was away. I am lucky the damage is something I can repair.
Any plastic pipe will work. Try some PVC water pipe. If you can not find any you can see the handle on the smaller hack saw style is made from broom stick. Don't use a old piece of metal like on the small saw it is to hard to insulate properly. Not worth the risk.
I do not know how hard it will be to find some of the materials in Egypt but take care to avoid electric sock or more likely fire.
The hill in the back ground was made by an old friend of mine. Howard Whitehouse. He inspired me to get into this and I hope it will do the same for you.