Creating a coil in tubing?
 

I would like to make some straws for a "cocktail" theme party using some 8mm boro tube.

part of my design calls for a helical coil in the middle of the straw I read somewhere (and forgot to bookmark it) about a tape that could be used over a mandrel that was heat and flame proof and would give the cushion that the glass needed when cooling as not to contract and be permanently part of the mandrel or crack.

anybody have any idea what it is called and where to get it or have a better way to create the coil

open to any ideas here

Ali would be the one to answer this... ;)

Maybe try wrapping the hot tube around a brass rod and slip it off before it cools/contracts enough to break?

a ribbon burner would come in handy here. I have a neon ribbon burner that works great for this. You heat up a section of it at a time. Usually one loop of the coil at a time. and make it as long as you like. Using a "mandrel" on this type of work just doesn't work, unless you have a lath.
try drawing the dia. on a graphite plate or better yet some refractory paper. heat up small sections of tubing at a time and lay it down on the drawing to guide you. the flat surface will also help in keeping the glass from drooping while you do it.
Let us know how it comes out.
Mike

graphite tape used mostly on lathe's Abr or mountain I believe sell it

acidfly

graphite tape.... THATS IT thank you ... will order some today ... in the mean time I will try Glassdog's method and see how that works for me ... no ribbon burner yet but its on my list if I ever see a used one going for a price I can afford.