another of my project questions

[breezer]

I will try it anyway, but am looking for advice / opinions

I intend to heat a 15mm copper pipe and i want to pull it so that it gets thinner at a point (the place of the point does not matter, since i will cut the pipe to size)

The idea is to make the pipe have a conical end.(once i have cut it off)

I know i could use a 15 mm to say 8mm reducer, but i want it to be to say 2 or 3mm (doesnt have to be exact)

I only have a butane blow torch (i suppose an oxy acetalene one would be better, but i dont have one and its only a one off test project , so if it doesnt work, it doesnt work)

so any advice or opions please

 

[Agile]

I dont think you will get it hot enough and I doubt that hard drawn 15 mm copper will act as you want.

Just possibly soft drawn copper might...

If you put the tube against heat resisting sheets at 90° to each other it will concentrate the heat a bit.

Tony

 

[breezer]

damn, thanks

 

[fumb]

Could you roll it?

Whip the blade out of a pipe cutter then use the wheels to just shrink the tube down as though you were cutting it?

Only a thought

 

[ChrisR]

Won't make any difference whether it's hard or soft if you heat it to soften it. Rolling it down would work. It'll work-harden rapidly, so keep heating it as hot as poss to soften again. Let the heat "soak through" , then you can quench it in water, or roll it down hot.

 

[Onetap]

Won't make any difference whether it's hard or soft if you heat it to soften it.

Annealling. It work hardens and will crack unless you anneall it. The soft annealled copper tube supplied in coils (table W to BS EN 1057) has a greater wall thickness than the Table X half hard straight lengths.

Some years ago, in the days when folk were chuntering about Indian & Pakistani building workers (much as they do about East Europeans today)
my father was working on a site with a Sikh labourer. The Sikh got a bit of copper 15mm offcut (or it might have been 1/2") and spent his lunch time tapping, heating, and drillling it, whilst everyone else was in the pub. By the time they got back he'd made it into a snake-charmers flute type pipe.

Do that, Mr. Brit Plumber.

 

[ChrisR]

Wot I meant was you'll get it as soft regardless of whether it was originally hard-drawn or soft-drawn. You won't have to fully "anneal" it to roll it down, relieving the stresses induced by work-hardening will do.