Flaring tubing

Whats the best way to flare a 1.5" copper tube out to 2"? This is a chimney for a boiler.

I know there are flaring tools available, but they are typically for much smaller pipe....anyone got a suggestion?

You could try popping down to your nearest custom exhaust builder.

They will have a hydraulic pipe expander designed for the job.

Failing that, it's possible to buy internal exhaust pipe expanders, which work on threaded rod. I've only ever used them for making a clamped, distorted pipe round again, so not sure if one would be up to the job.

Have a look at the adverts for one, then it should be easy enough to duplicate in the workshop.

This sort of thing on youtube; https://www.youtube.com/watch?v=zcz6CSVmxQU

N.B. turn the sound down, and scroll to about 1 Min 45 

Bill

Edited By peak4 on 16/10/2017 23:49:00

Another method - try googling "youtube diy metal spinning"

Flared as in musical instruments or brake pipes? Or flared as in expanded for a parallel overlap joint - as in vehicle exhaust sections? If the latter, the exhaust fitters are likely the easiest option. Or search out a plumbing fitting?

Its fun to just use a hammer and a spike, beat the pipe with the hammer on its outer edge, thus enlarging the diameter and slowly work down the pipe as the outer edge enlarges. Anneal by heating to cherry red frequently and quenching in cold water to speed up the process. You may find a straight pein hammer best.
BobH