superfly, what bike do you have, any pictures?
Yes you can fill a steel tube or pipe with kiln dried silver sand (if it gets damp put it in the oven for a while until its bone dry) and heat it up so its glowing red and bend it quite easily. If your tube bender isn't the same size as your tube/pipe it will crush or deform it. Personally though i'd use solid round bar for this project.
Corrobend is pretty much ideal for jobs like this, and has the added advantage of being reusable. http://www.bendalloy.co.uk/
Thanks a million I will look into that, and get the proper sand, so far I use the beach sand...