Shortening a baseboard radiator - very thin pipe
How about a much finer toothed hacksaw? They make some really fine toothed saws for hobbyists. These may not last very long when cutting copper pipe (and not succeed in cutting even one steel pipe) but you might not need to do that many cuts.
Saw a little, turn the pipe a little, and saw some more. This way most of the sawing is across (nearly tangent to) the surface as opposed to across the cut edge. Don't apply too much pressure while sawing.
Heating systems operate at much lower pressures compared with water supply systems so thinner pipes can be used. Of course, the thinner pipes are cheaper.
The disadvantages of crab apple trees. In summer, the apples are too sour to pick and eat. In winter the birds come and leave dropping all over the place.
Last edited by AllanJ; 11-12-2012 at 08:18 AM.