On Mon, 24 Oct 2011 19:40:31 -0400, blueman wrote:


However, there are times when I would like to have a larger air supply
tank such as when I am blowing out my irrigation system. Of course the
steady-state is limited by the compressor motor to about 4-5 CFM@90 psi.

I am in the same situation. I also thought about the exact same tank.
Last year I paid the $20 for a commercial blow job. His compressor
put out 100 CFM. It took several minutes for the remote heads to stop
blowing mist. My observation is the 8 gallons of air will blow out
the near heads and is exhausted in a few seconds, another 11 gallons
may extend this to a fraction of a minute. The consensus on the
Internet is a min of 10 to 15 CFM is required. This somewhat depends
on the slope of the lawn. The steeper the slope the more CFM
required. In a previous house with a flatter lawn and auto drains at
the low spots I used my small compressor for years with no problem.

Next I thought about the $129 HF 6 CFM in conjunction with my present
compressor. It is close, but I am not sure if my expected lifetime
would justify this expense.

So my solution this year was to blow out and use a shop vac to
evacuate the far heads. After doing that I decided to hire the pro
next year. Tomorrow it is going to be 14 so I hope I got enough water
out. A little water in the poly pipe won't cause a problem, sprinkler
heads are cheap, the expensive anti siphon is water free.

Lets us know how you make out.