On Tuesday, September 1, 2015 at 9:27:25 AM UTC-4, Stormin Mormon wrote:
I'm working with some church guys on a roof shingle
project. The compressor is in the garage, at the
power socket. There is air hose going to the air
nailer, which is in use on the roof.

A couple times, the hose was not long enough to
reach. The question was raised, should we get more
hose, or an extension cord and move the compressor?

There can be problems with air flow. There is also
voltage drop in extension cords. Which should we use?

--
.
Christopher A. Young
learn more about Jesus
. www.lds.org
.
.

OK...serious comment:

Everyone is recommending a longer air hose as opposed to an extension cord, yet no one knows anything about the circuit that the compressor is currently plugged in to.

For all we know it's 14g wire, 5000' feet from the source. The voltage drop could already be huge. Let's say you used a 10' 12g extension cord to move the compressor. Would there really be much more of a drop, enough to make any difference?

This may be one of those cases where we don't know enough about the current (pun intended) situation to really offer a definitive answer. For all we know, there is another receptacle that is physically farther from the roof but electrically closer to the source such that even after adding a decent extension cord there may be less overall voltage drop than you're getting now.

Just sayin'